#hypothalamus — Public Fediverse posts
Live and recent posts from across the Fediverse tagged #hypothalamus, aggregated by home.social.
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DATE: September 23, 2026 at 10:00AM
SOURCE: PSYPOST.ORG** Research quality varies widely from fantastic to small exploratory studies. Please check research methods when conclusions are very important to you. **
-------------------------------------------------TITLE: Orexin neurons act as an effort-tracking system in the brain
URL: https://www.psypost.org/orexin-neurons-act-as-an-effort-tracking-system-in-the-brain/
A new study found that specialized brain cells called orexin neurons act as an effort-tracking system that spikes in activity when an animal expects a reward. The research suggests that turning these cells on or off can directly adjust how hard an animal is willing to work for a goal. The findings were published in PNAS.
Orexin neurons are a small but highly influential group of cells located deep in the hypothalamus. This region at the base of the brain manages basic survival functions like body temperature, thirst, and fatigue. Originally discovered for their role in regulating sleep, wakefulness, and appetite, these neurons also play a massive role in motivated behavior.
Motivation is the internal psychological drive that initiates and sustains our actions toward a goal. To successfully reach a goal, an animal must evaluate a situation, predict the outcome, and apply the right amount of effort.
A 2014 review established the foundational idea that orexin does not just regulate sleep and hunger, but acts as a central engine for motivating animals to pursue goals. Building on this concept, a 2024 study in mice indicated that orexin neurons are essential for choosing to expend physical effort instead of settling for easy temptations.
“Orexin has traditionally been studied for its role in wakefulness, with much of the evidence coming from studies,” study author Hiroyuki Mizoguchi, an associate professor in the Department of Neuropsychopharmacology and Hospital Pharmacy at Nagoya University Graduate School of Medicine, told PsyPost. “Although previous work has also implicated orexin neurons in motivated behavior in mice, exactly how their activity relates to reward prediction and effort has remained unclear.”
To bridge this gap, the research team, which also included Yutao Dong, developed a genetically modified rat model that allowed them to monitor and manipulate orexin neurons as the animals worked for food. Rats are particularly useful for this type of research because their advanced learning abilities make them well-suited for complex behavioral tests.
First, the researchers used a chemical technique called chemogenetics to selectively activate orexin neurons. They trained hungry rats to interact with a touchscreen to receive a small food pellet. To measure motivation, they used a progressive ratio test, where the amount of effort required to get a single food pellet steadily increased. For example, a rat might need to touch the screen five times for the first reward, but eventually have to touch it dozens of times for the next.
This escalating test continued until the rats gave up, providing a “breakpoint” that reflects their maximum willingness to work. When the researchers artificially activated the orexin neurons, the rats’ motivation increased. They displayed a higher breakpoint, meaning they were willing to tap the screen many more times to secure a single reward compared to their baseline performance.
Next, the team used a technique called fiber photometry to observe the natural activity of these cells in real time. When a neuron fires, calcium floods into the cell. By tracking these calcium signals, the scientists could monitor exactly when the orexin neurons were active while the rats performed tasks requiring varying levels of effort.
The researchers noticed a distinct pattern. As the rats tapped the screen and expected a food pellet, orexin neuron activity sharply increased. Once the rats received and ate the food, the cell activity dropped back down to normal levels.
The intensity of this brain signal also scaled with the amount of effort required. The neurons fired more strongly during the difficult progressive ratio test than during an easy task that required only one or two screen taps.
Additionally, the researchers tested what would happen if they tricked the rats by withholding the expected food pellet after a completed task. In these frustrating scenarios, the orexin activity stayed high. This suggests the cells maintain a state of prolonged expectation or stress when a predicted goal is not met.
“We were surprised that orexin neuronal activity changed across several distinct situations,” Mizoguchi said, noting that the neurons became active during reward prediction “rather than only when the reward was received.”
To test whether this burst of activity is directly tied to goal-directed action, the scientists used optogenetics. This method uses targeted flashes of light to turn specific brain cells on or off. The researchers trained the rats to tap the screen five times for a reward.
Right after the rats made their final tap, the researchers flashed a blue light into the brain to temporarily silence the orexin neurons during the brief window of reward anticipation. Suppressing the cells at this exact moment caused the rats to perform poorly. They took noticeably longer to complete the trials compared to when their brain activity was left alone, indicating that their drive to seek the reward had been interrupted.
“Our findings suggest that orexin neurons are part of a broader brain system that helps translate reward expectations into motivated action,” Mizoguchi explained. “Motivation does not depend on orexin alone, but these neurons may help the brain determine whether a reward is worth the effort.”
The findings are in line with research covered by PsyPost in 2016, which found that blocking orexin signaling reduced compulsive drug-seeking behavior. A study covered by PsyPost in 2017 similarly observed that turning down these receptors lowered drug intake. It is worth noting that those earlier experiments examined extreme cocaine addiction models rather than general reward prediction, but they still point to orexin’s fundamental role in driving animals toward a desired outcome.
As with all research, there are a few things to keep in mind regarding the current study. The researchers only used food as a reward, so it is still unknown if orexin neurons act the same way for other types of goals. Future research will need to explore whether similar brain activity occurs during social interactions, mating behaviors, or avoiding danger.
Additionally, the light manipulation targeted the entire population of orexin neurons at once. The hypothalamus contains different sub-groups of these cells, and future studies might need to separate them to see if they handle motivation differently. The team also noted that while turning the neurons off reduced effort, artificially stimulating them with light did not reliably increase motivation. This might be because the hungry rats were already operating at near-maximum motivation, making it hard to push their effort levels even higher through artificial means.
“A key caveat is that the relationship between orexin neuronal activity and motivated behavior is not straightforward; its effects may vary with the experimental conditions and with how neuronal activity is manipulated,” Mizoguchi pointed out. “Moreover, because this was a basic study in rats, not all of the findings can necessarily be applied to humans.”
Moving forward, the research team aims to map the broader neural circuits involved in these processes. “Our long-term goal is to understand how orexin neuronal activity is regulated and how these neurons influence motivated behavior,” Mizoguchi said. “We aim to identify the signals that orexin neurons transmit to downstream targets and the factors that stabilize or destabilize their activity.”
“Difficulty maintaining motivation can have substantial social and medical consequences,” he added. “Although the present study did not examine specific disorders or treatments, we hope that our findings will ultimately contribute to a better understanding of conditions involving reduced motivation and provide a foundation for future therapeutic research.”
The study, “Reward prediction is encoded by orexin neuron activity during motivated behavior,” was authored by Yutao Dong, Sheikh Mizanur Rahaman, Wenjun Zhu, Ayumu Inutsuka, Daisuke Ono, Rinako Tanaka, Tetsuo Matsuzaki, Eiji Shibata, Madoka Isobe, Shuntaro Izawa, Akihiro Yamanaka, Kiyofumi Yamada, and Hiroyuki Mizoguchi.
URL: https://www.psypost.org/orexin-neurons-act-as-an-effort-tracking-system-in-the-brain/
-------------------------------------------------
Private, vetted email list for mental health professionals: https://www.clinicians-exchange.org
Unofficial Psychology Today Xitter to toot feed at Psych Today Unofficial Bot @PTUnofficialBot
-------------------------------------------------
#psychology #counseling #socialwork #psychotherapy @psychotherapist @psychotherapists @psychology @socialpsych @socialwork @psychiatry #mentalhealth #psychiatry #healthcare #depression #psychotherapist #orexin #motivation #rewardprediction #neuroscience #brainresearch #itevations #optogenetics #chemogenetics #hypothalamus # motivatedbehavior
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DATE: September 23, 2026 at 10:00AM
SOURCE: PSYPOST.ORG** Research quality varies widely from fantastic to small exploratory studies. Please check research methods when conclusions are very important to you. **
-------------------------------------------------TITLE: Orexin neurons act as an effort-tracking system in the brain
URL: https://www.psypost.org/orexin-neurons-act-as-an-effort-tracking-system-in-the-brain/
A new study found that specialized brain cells called orexin neurons act as an effort-tracking system that spikes in activity when an animal expects a reward. The research suggests that turning these cells on or off can directly adjust how hard an animal is willing to work for a goal. The findings were published in PNAS.
Orexin neurons are a small but highly influential group of cells located deep in the hypothalamus. This region at the base of the brain manages basic survival functions like body temperature, thirst, and fatigue. Originally discovered for their role in regulating sleep, wakefulness, and appetite, these neurons also play a massive role in motivated behavior.
Motivation is the internal psychological drive that initiates and sustains our actions toward a goal. To successfully reach a goal, an animal must evaluate a situation, predict the outcome, and apply the right amount of effort.
A 2014 review established the foundational idea that orexin does not just regulate sleep and hunger, but acts as a central engine for motivating animals to pursue goals. Building on this concept, a 2024 study in mice indicated that orexin neurons are essential for choosing to expend physical effort instead of settling for easy temptations.
“Orexin has traditionally been studied for its role in wakefulness, with much of the evidence coming from studies,” study author Hiroyuki Mizoguchi, an associate professor in the Department of Neuropsychopharmacology and Hospital Pharmacy at Nagoya University Graduate School of Medicine, told PsyPost. “Although previous work has also implicated orexin neurons in motivated behavior in mice, exactly how their activity relates to reward prediction and effort has remained unclear.”
To bridge this gap, the research team, which also included Yutao Dong, developed a genetically modified rat model that allowed them to monitor and manipulate orexin neurons as the animals worked for food. Rats are particularly useful for this type of research because their advanced learning abilities make them well-suited for complex behavioral tests.
First, the researchers used a chemical technique called chemogenetics to selectively activate orexin neurons. They trained hungry rats to interact with a touchscreen to receive a small food pellet. To measure motivation, they used a progressive ratio test, where the amount of effort required to get a single food pellet steadily increased. For example, a rat might need to touch the screen five times for the first reward, but eventually have to touch it dozens of times for the next.
This escalating test continued until the rats gave up, providing a “breakpoint” that reflects their maximum willingness to work. When the researchers artificially activated the orexin neurons, the rats’ motivation increased. They displayed a higher breakpoint, meaning they were willing to tap the screen many more times to secure a single reward compared to their baseline performance.
Next, the team used a technique called fiber photometry to observe the natural activity of these cells in real time. When a neuron fires, calcium floods into the cell. By tracking these calcium signals, the scientists could monitor exactly when the orexin neurons were active while the rats performed tasks requiring varying levels of effort.
The researchers noticed a distinct pattern. As the rats tapped the screen and expected a food pellet, orexin neuron activity sharply increased. Once the rats received and ate the food, the cell activity dropped back down to normal levels.
The intensity of this brain signal also scaled with the amount of effort required. The neurons fired more strongly during the difficult progressive ratio test than during an easy task that required only one or two screen taps.
Additionally, the researchers tested what would happen if they tricked the rats by withholding the expected food pellet after a completed task. In these frustrating scenarios, the orexin activity stayed high. This suggests the cells maintain a state of prolonged expectation or stress when a predicted goal is not met.
“We were surprised that orexin neuronal activity changed across several distinct situations,” Mizoguchi said, noting that the neurons became active during reward prediction “rather than only when the reward was received.”
To test whether this burst of activity is directly tied to goal-directed action, the scientists used optogenetics. This method uses targeted flashes of light to turn specific brain cells on or off. The researchers trained the rats to tap the screen five times for a reward.
Right after the rats made their final tap, the researchers flashed a blue light into the brain to temporarily silence the orexin neurons during the brief window of reward anticipation. Suppressing the cells at this exact moment caused the rats to perform poorly. They took noticeably longer to complete the trials compared to when their brain activity was left alone, indicating that their drive to seek the reward had been interrupted.
“Our findings suggest that orexin neurons are part of a broader brain system that helps translate reward expectations into motivated action,” Mizoguchi explained. “Motivation does not depend on orexin alone, but these neurons may help the brain determine whether a reward is worth the effort.”
The findings are in line with research covered by PsyPost in 2016, which found that blocking orexin signaling reduced compulsive drug-seeking behavior. A study covered by PsyPost in 2017 similarly observed that turning down these receptors lowered drug intake. It is worth noting that those earlier experiments examined extreme cocaine addiction models rather than general reward prediction, but they still point to orexin’s fundamental role in driving animals toward a desired outcome.
As with all research, there are a few things to keep in mind regarding the current study. The researchers only used food as a reward, so it is still unknown if orexin neurons act the same way for other types of goals. Future research will need to explore whether similar brain activity occurs during social interactions, mating behaviors, or avoiding danger.
Additionally, the light manipulation targeted the entire population of orexin neurons at once. The hypothalamus contains different sub-groups of these cells, and future studies might need to separate them to see if they handle motivation differently. The team also noted that while turning the neurons off reduced effort, artificially stimulating them with light did not reliably increase motivation. This might be because the hungry rats were already operating at near-maximum motivation, making it hard to push their effort levels even higher through artificial means.
“A key caveat is that the relationship between orexin neuronal activity and motivated behavior is not straightforward; its effects may vary with the experimental conditions and with how neuronal activity is manipulated,” Mizoguchi pointed out. “Moreover, because this was a basic study in rats, not all of the findings can necessarily be applied to humans.”
Moving forward, the research team aims to map the broader neural circuits involved in these processes. “Our long-term goal is to understand how orexin neuronal activity is regulated and how these neurons influence motivated behavior,” Mizoguchi said. “We aim to identify the signals that orexin neurons transmit to downstream targets and the factors that stabilize or destabilize their activity.”
“Difficulty maintaining motivation can have substantial social and medical consequences,” he added. “Although the present study did not examine specific disorders or treatments, we hope that our findings will ultimately contribute to a better understanding of conditions involving reduced motivation and provide a foundation for future therapeutic research.”
The study, “Reward prediction is encoded by orexin neuron activity during motivated behavior,” was authored by Yutao Dong, Sheikh Mizanur Rahaman, Wenjun Zhu, Ayumu Inutsuka, Daisuke Ono, Rinako Tanaka, Tetsuo Matsuzaki, Eiji Shibata, Madoka Isobe, Shuntaro Izawa, Akihiro Yamanaka, Kiyofumi Yamada, and Hiroyuki Mizoguchi.
URL: https://www.psypost.org/orexin-neurons-act-as-an-effort-tracking-system-in-the-brain/
-------------------------------------------------
Private, vetted email list for mental health professionals: https://www.clinicians-exchange.org
Unofficial Psychology Today Xitter to toot feed at Psych Today Unofficial Bot @PTUnofficialBot
-------------------------------------------------
#psychology #counseling #socialwork #psychotherapy @psychotherapist @psychotherapists @psychology @socialpsych @socialwork @psychiatry #mentalhealth #psychiatry #healthcare #depression #psychotherapist #orexin #motivation #rewardprediction #neuroscience #brainresearch #itevations #optogenetics #chemogenetics #hypothalamus # motivatedbehavior
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DATE: September 23, 2026 at 10:00AM
SOURCE: PSYPOST.ORG** Research quality varies widely from fantastic to small exploratory studies. Please check research methods when conclusions are very important to you. **
-------------------------------------------------TITLE: Orexin neurons act as an effort-tracking system in the brain
URL: https://www.psypost.org/orexin-neurons-act-as-an-effort-tracking-system-in-the-brain/
A new study found that specialized brain cells called orexin neurons act as an effort-tracking system that spikes in activity when an animal expects a reward. The research suggests that turning these cells on or off can directly adjust how hard an animal is willing to work for a goal. The findings were published in PNAS.
Orexin neurons are a small but highly influential group of cells located deep in the hypothalamus. This region at the base of the brain manages basic survival functions like body temperature, thirst, and fatigue. Originally discovered for their role in regulating sleep, wakefulness, and appetite, these neurons also play a massive role in motivated behavior.
Motivation is the internal psychological drive that initiates and sustains our actions toward a goal. To successfully reach a goal, an animal must evaluate a situation, predict the outcome, and apply the right amount of effort.
A 2014 review established the foundational idea that orexin does not just regulate sleep and hunger, but acts as a central engine for motivating animals to pursue goals. Building on this concept, a 2024 study in mice indicated that orexin neurons are essential for choosing to expend physical effort instead of settling for easy temptations.
“Orexin has traditionally been studied for its role in wakefulness, with much of the evidence coming from studies,” study author Hiroyuki Mizoguchi, an associate professor in the Department of Neuropsychopharmacology and Hospital Pharmacy at Nagoya University Graduate School of Medicine, told PsyPost. “Although previous work has also implicated orexin neurons in motivated behavior in mice, exactly how their activity relates to reward prediction and effort has remained unclear.”
To bridge this gap, the research team, which also included Yutao Dong, developed a genetically modified rat model that allowed them to monitor and manipulate orexin neurons as the animals worked for food. Rats are particularly useful for this type of research because their advanced learning abilities make them well-suited for complex behavioral tests.
First, the researchers used a chemical technique called chemogenetics to selectively activate orexin neurons. They trained hungry rats to interact with a touchscreen to receive a small food pellet. To measure motivation, they used a progressive ratio test, where the amount of effort required to get a single food pellet steadily increased. For example, a rat might need to touch the screen five times for the first reward, but eventually have to touch it dozens of times for the next.
This escalating test continued until the rats gave up, providing a “breakpoint” that reflects their maximum willingness to work. When the researchers artificially activated the orexin neurons, the rats’ motivation increased. They displayed a higher breakpoint, meaning they were willing to tap the screen many more times to secure a single reward compared to their baseline performance.
Next, the team used a technique called fiber photometry to observe the natural activity of these cells in real time. When a neuron fires, calcium floods into the cell. By tracking these calcium signals, the scientists could monitor exactly when the orexin neurons were active while the rats performed tasks requiring varying levels of effort.
The researchers noticed a distinct pattern. As the rats tapped the screen and expected a food pellet, orexin neuron activity sharply increased. Once the rats received and ate the food, the cell activity dropped back down to normal levels.
The intensity of this brain signal also scaled with the amount of effort required. The neurons fired more strongly during the difficult progressive ratio test than during an easy task that required only one or two screen taps.
Additionally, the researchers tested what would happen if they tricked the rats by withholding the expected food pellet after a completed task. In these frustrating scenarios, the orexin activity stayed high. This suggests the cells maintain a state of prolonged expectation or stress when a predicted goal is not met.
“We were surprised that orexin neuronal activity changed across several distinct situations,” Mizoguchi said, noting that the neurons became active during reward prediction “rather than only when the reward was received.”
To test whether this burst of activity is directly tied to goal-directed action, the scientists used optogenetics. This method uses targeted flashes of light to turn specific brain cells on or off. The researchers trained the rats to tap the screen five times for a reward.
Right after the rats made their final tap, the researchers flashed a blue light into the brain to temporarily silence the orexin neurons during the brief window of reward anticipation. Suppressing the cells at this exact moment caused the rats to perform poorly. They took noticeably longer to complete the trials compared to when their brain activity was left alone, indicating that their drive to seek the reward had been interrupted.
“Our findings suggest that orexin neurons are part of a broader brain system that helps translate reward expectations into motivated action,” Mizoguchi explained. “Motivation does not depend on orexin alone, but these neurons may help the brain determine whether a reward is worth the effort.”
The findings are in line with research covered by PsyPost in 2016, which found that blocking orexin signaling reduced compulsive drug-seeking behavior. A study covered by PsyPost in 2017 similarly observed that turning down these receptors lowered drug intake. It is worth noting that those earlier experiments examined extreme cocaine addiction models rather than general reward prediction, but they still point to orexin’s fundamental role in driving animals toward a desired outcome.
As with all research, there are a few things to keep in mind regarding the current study. The researchers only used food as a reward, so it is still unknown if orexin neurons act the same way for other types of goals. Future research will need to explore whether similar brain activity occurs during social interactions, mating behaviors, or avoiding danger.
Additionally, the light manipulation targeted the entire population of orexin neurons at once. The hypothalamus contains different sub-groups of these cells, and future studies might need to separate them to see if they handle motivation differently. The team also noted that while turning the neurons off reduced effort, artificially stimulating them with light did not reliably increase motivation. This might be because the hungry rats were already operating at near-maximum motivation, making it hard to push their effort levels even higher through artificial means.
“A key caveat is that the relationship between orexin neuronal activity and motivated behavior is not straightforward; its effects may vary with the experimental conditions and with how neuronal activity is manipulated,” Mizoguchi pointed out. “Moreover, because this was a basic study in rats, not all of the findings can necessarily be applied to humans.”
Moving forward, the research team aims to map the broader neural circuits involved in these processes. “Our long-term goal is to understand how orexin neuronal activity is regulated and how these neurons influence motivated behavior,” Mizoguchi said. “We aim to identify the signals that orexin neurons transmit to downstream targets and the factors that stabilize or destabilize their activity.”
“Difficulty maintaining motivation can have substantial social and medical consequences,” he added. “Although the present study did not examine specific disorders or treatments, we hope that our findings will ultimately contribute to a better understanding of conditions involving reduced motivation and provide a foundation for future therapeutic research.”
The study, “Reward prediction is encoded by orexin neuron activity during motivated behavior,” was authored by Yutao Dong, Sheikh Mizanur Rahaman, Wenjun Zhu, Ayumu Inutsuka, Daisuke Ono, Rinako Tanaka, Tetsuo Matsuzaki, Eiji Shibata, Madoka Isobe, Shuntaro Izawa, Akihiro Yamanaka, Kiyofumi Yamada, and Hiroyuki Mizoguchi.
URL: https://www.psypost.org/orexin-neurons-act-as-an-effort-tracking-system-in-the-brain/
-------------------------------------------------
Private, vetted email list for mental health professionals: https://www.clinicians-exchange.org
Unofficial Psychology Today Xitter to toot feed at Psych Today Unofficial Bot @PTUnofficialBot
-------------------------------------------------
#psychology #counseling #socialwork #psychotherapy @psychotherapist @psychotherapists @psychology @socialpsych @socialwork @psychiatry #mentalhealth #psychiatry #healthcare #depression #psychotherapist #orexin #motivation #rewardprediction #neuroscience #brainresearch #itevations #optogenetics #chemogenetics #hypothalamus # motivatedbehavior
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DATE: September 23, 2026 at 10:00AM
SOURCE: PSYPOST.ORG** Research quality varies widely from fantastic to small exploratory studies. Please check research methods when conclusions are very important to you. **
-------------------------------------------------TITLE: Orexin neurons act as an effort-tracking system in the brain
URL: https://www.psypost.org/orexin-neurons-act-as-an-effort-tracking-system-in-the-brain/
A new study found that specialized brain cells called orexin neurons act as an effort-tracking system that spikes in activity when an animal expects a reward. The research suggests that turning these cells on or off can directly adjust how hard an animal is willing to work for a goal. The findings were published in PNAS.
Orexin neurons are a small but highly influential group of cells located deep in the hypothalamus. This region at the base of the brain manages basic survival functions like body temperature, thirst, and fatigue. Originally discovered for their role in regulating sleep, wakefulness, and appetite, these neurons also play a massive role in motivated behavior.
Motivation is the internal psychological drive that initiates and sustains our actions toward a goal. To successfully reach a goal, an animal must evaluate a situation, predict the outcome, and apply the right amount of effort.
A 2014 review established the foundational idea that orexin does not just regulate sleep and hunger, but acts as a central engine for motivating animals to pursue goals. Building on this concept, a 2024 study in mice indicated that orexin neurons are essential for choosing to expend physical effort instead of settling for easy temptations.
“Orexin has traditionally been studied for its role in wakefulness, with much of the evidence coming from studies,” study author Hiroyuki Mizoguchi, an associate professor in the Department of Neuropsychopharmacology and Hospital Pharmacy at Nagoya University Graduate School of Medicine, told PsyPost. “Although previous work has also implicated orexin neurons in motivated behavior in mice, exactly how their activity relates to reward prediction and effort has remained unclear.”
To bridge this gap, the research team, which also included Yutao Dong, developed a genetically modified rat model that allowed them to monitor and manipulate orexin neurons as the animals worked for food. Rats are particularly useful for this type of research because their advanced learning abilities make them well-suited for complex behavioral tests.
First, the researchers used a chemical technique called chemogenetics to selectively activate orexin neurons. They trained hungry rats to interact with a touchscreen to receive a small food pellet. To measure motivation, they used a progressive ratio test, where the amount of effort required to get a single food pellet steadily increased. For example, a rat might need to touch the screen five times for the first reward, but eventually have to touch it dozens of times for the next.
This escalating test continued until the rats gave up, providing a “breakpoint” that reflects their maximum willingness to work. When the researchers artificially activated the orexin neurons, the rats’ motivation increased. They displayed a higher breakpoint, meaning they were willing to tap the screen many more times to secure a single reward compared to their baseline performance.
Next, the team used a technique called fiber photometry to observe the natural activity of these cells in real time. When a neuron fires, calcium floods into the cell. By tracking these calcium signals, the scientists could monitor exactly when the orexin neurons were active while the rats performed tasks requiring varying levels of effort.
The researchers noticed a distinct pattern. As the rats tapped the screen and expected a food pellet, orexin neuron activity sharply increased. Once the rats received and ate the food, the cell activity dropped back down to normal levels.
The intensity of this brain signal also scaled with the amount of effort required. The neurons fired more strongly during the difficult progressive ratio test than during an easy task that required only one or two screen taps.
Additionally, the researchers tested what would happen if they tricked the rats by withholding the expected food pellet after a completed task. In these frustrating scenarios, the orexin activity stayed high. This suggests the cells maintain a state of prolonged expectation or stress when a predicted goal is not met.
“We were surprised that orexin neuronal activity changed across several distinct situations,” Mizoguchi said, noting that the neurons became active during reward prediction “rather than only when the reward was received.”
To test whether this burst of activity is directly tied to goal-directed action, the scientists used optogenetics. This method uses targeted flashes of light to turn specific brain cells on or off. The researchers trained the rats to tap the screen five times for a reward.
Right after the rats made their final tap, the researchers flashed a blue light into the brain to temporarily silence the orexin neurons during the brief window of reward anticipation. Suppressing the cells at this exact moment caused the rats to perform poorly. They took noticeably longer to complete the trials compared to when their brain activity was left alone, indicating that their drive to seek the reward had been interrupted.
“Our findings suggest that orexin neurons are part of a broader brain system that helps translate reward expectations into motivated action,” Mizoguchi explained. “Motivation does not depend on orexin alone, but these neurons may help the brain determine whether a reward is worth the effort.”
The findings are in line with research covered by PsyPost in 2016, which found that blocking orexin signaling reduced compulsive drug-seeking behavior. A study covered by PsyPost in 2017 similarly observed that turning down these receptors lowered drug intake. It is worth noting that those earlier experiments examined extreme cocaine addiction models rather than general reward prediction, but they still point to orexin’s fundamental role in driving animals toward a desired outcome.
As with all research, there are a few things to keep in mind regarding the current study. The researchers only used food as a reward, so it is still unknown if orexin neurons act the same way for other types of goals. Future research will need to explore whether similar brain activity occurs during social interactions, mating behaviors, or avoiding danger.
Additionally, the light manipulation targeted the entire population of orexin neurons at once. The hypothalamus contains different sub-groups of these cells, and future studies might need to separate them to see if they handle motivation differently. The team also noted that while turning the neurons off reduced effort, artificially stimulating them with light did not reliably increase motivation. This might be because the hungry rats were already operating at near-maximum motivation, making it hard to push their effort levels even higher through artificial means.
“A key caveat is that the relationship between orexin neuronal activity and motivated behavior is not straightforward; its effects may vary with the experimental conditions and with how neuronal activity is manipulated,” Mizoguchi pointed out. “Moreover, because this was a basic study in rats, not all of the findings can necessarily be applied to humans.”
Moving forward, the research team aims to map the broader neural circuits involved in these processes. “Our long-term goal is to understand how orexin neuronal activity is regulated and how these neurons influence motivated behavior,” Mizoguchi said. “We aim to identify the signals that orexin neurons transmit to downstream targets and the factors that stabilize or destabilize their activity.”
“Difficulty maintaining motivation can have substantial social and medical consequences,” he added. “Although the present study did not examine specific disorders or treatments, we hope that our findings will ultimately contribute to a better understanding of conditions involving reduced motivation and provide a foundation for future therapeutic research.”
The study, “Reward prediction is encoded by orexin neuron activity during motivated behavior,” was authored by Yutao Dong, Sheikh Mizanur Rahaman, Wenjun Zhu, Ayumu Inutsuka, Daisuke Ono, Rinako Tanaka, Tetsuo Matsuzaki, Eiji Shibata, Madoka Isobe, Shuntaro Izawa, Akihiro Yamanaka, Kiyofumi Yamada, and Hiroyuki Mizoguchi.
URL: https://www.psypost.org/orexin-neurons-act-as-an-effort-tracking-system-in-the-brain/
-------------------------------------------------
Private, vetted email list for mental health professionals: https://www.clinicians-exchange.org
Unofficial Psychology Today Xitter to toot feed at Psych Today Unofficial Bot @PTUnofficialBot
-------------------------------------------------
#psychology #counseling #socialwork #psychotherapy @psychotherapist @psychotherapists @psychology @socialpsych @socialwork @psychiatry #mentalhealth #psychiatry #healthcare #depression #psychotherapist #orexin #motivation #rewardprediction #neuroscience #brainresearch #itevations #optogenetics #chemogenetics #hypothalamus # motivatedbehavior
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DATE: September 22, 2026 at 02:30PM
SOURCE: PSYPOST.ORG** Research quality varies widely from fantastic to small exploratory studies. Please check research methods when conclusions are very important to you. **
-------------------------------------------------TITLE: Brain scans reveal how artificial sweeteners affect our reward circuits differently than sugar
An experimental study compared changes in brain activity after ingestion of water and different types of flavored waters. Results showed that cerebral blood flow in the hypothalamus (a brain region that controls homeostatic processes like hunger and thirst) was not differentially affected by any of the drinks. However, the ventral tegmental area (a midbrain region involved in reward and motivation) showed lower changes in cerebral blood flow after sucrose than after water, sucralose, or monk fruit drink ingestion. The paper was published in The American Journal of Clinical Nutrition.
As obesity rates have risen worldwide, reducing excessive energy intake has become an important goal for both individuals and public health. One widely used strategy is to replace sugar with low- or no-calorie sweeteners, particularly in beverages, where added sugars can contribute substantially to daily calorie intake. Although concerns are often raised that exposure to sweetness might increase cravings for sweet foods, current evidence does not consistently support this idea.
At the same time, low- and no-calorie sweeteners should not necessarily be viewed as a single, uniform group. Different sweeteners can vary in taste, metabolic effects, effects on the gut microbiome, and the physiological responses they produce after consumption. Sugars themselves also differ in how they are processed by the body and in their effects on blood glucose and other metabolic processes.
Because the brain plays a central role in hunger, satiety, reward, and energy regulation, researchers are increasingly interested in how different sweeteners influence brain activity after consumption. Brain-imaging research suggests that caloric sugars and non-caloric sweeteners may sometimes produce different responses in regions involved in appetite regulation, including the hypothalamus, although findings remain inconsistent.
Study author Paul AM Smeets, an associate professor at the Division of Human Nutrition and Health at Wageningen University Research, and his colleagues conducted a study in which they examined changes in brain activity and physiological markers after the ingestion of flavored waters sweetened with the sugar sucrose or various low-no-calorie sweeteners.
“I have done previous work on low-/no-calorie sweeteners (LNCS), also with the use of brain imaging (fMRI),” Smeets explained. “There has been quite some negative press about potential adverse effects of sweet compounds on metabolism and energy intake. The evidence in favor of no adverse effects such as subsequent increased food intake is substantial. That said, there is research emerging that shows differential effects of different LNCS because they are metabolized differently by the body. Therefore, when I was approached by an ingredient company to do a study on a range of LNCS I was eager to pursue such a study.”
The researchers hypothesized that sugar sucrose would elicit decreased cerebral blood flow (indicating decreased neural activity) in brain areas related to food intake regulation and reward 30 minutes after ingestion. They expected that low- or no-calorie sweeteners and water would not produce such effects due to their low or absent energy content.
Study participants were 30 healthy individuals. Fifteen of them were men. Their average age was 23 years. They completed six treatment sessions between February 2023 and March 2024.
The treatment consisted of ingestion of 500 milliliters of either water or one of five equally sweet, lemon-lime flavored waters sweetened with sucrose (25 grams, 97 kcal) or sucralose, stevia extract, monk fruit extract, or allulose + stevia extract.
Sucralose is a high-intensity artificial sweetener made from modified sucrose that provides sweetness with virtually no calories. Stevia extract is a plant-derived sweetener obtained from Stevia rebaudiana and contains sweet compounds called steviol glycosides. Monk fruit extract is a natural high-intensity sweetener derived from Siraitia grosvenorii fruit. Allulose is a rare low-calorie sugar with properties similar to ordinary sugar. Stevia is mixed with allulose to increase sweetness while keeping calorie content low. These sweeteners add little or no calories to a drink.
At the start of the treatment procedure, participants completed magnetic resonance imaging scans of their brains and of their stomachs. They also answered questions about appetite and well-being verbally. After this, they drank the drink assigned to them on the occasion. This was followed by two more scans of their brains and of their stomachs at different times up to 45 minutes after drinking.
Participants gave blood samples at the start and five more times up to an hour after drinking their assigned beverage (except on the day they received water). After the first sip, participants rated the tastiness and sweetness of the drink they consumed. All participants consumed their drinks within five minutes. Sixty minutes after drinking, after all the procedures were completed, participants were offered a takeaway breakfast.
“It was a huge study, with approximately 180 intense test sessions that combined brain imaging, blood sampling and stomach imaging,” Smeets noted. “I’m really proud of the research team that did the data collection.”
Results showed that all sweet drinks were liked equally, except monk fruit, which was liked modestly less than the sucrose-sweetened drink. All sweetened drinks except the one with monk fruit were liked more than water. All sweetened drinks were perceived as sweeter than water. The monk fruit-sweetened drink and the drink sweetened with allulose+stevia were rated modestly less sweet than the sucrose-sweetened drink.
Cerebral blood flow in the hypothalamus was similarly affected by all sweet drinks. Cerebral blood flow is an indirect indicator of activity in a particular region of the brain, with higher cerebral blood flow generally suggesting higher neural activity.
In the ventral tegmental area, the change in the cerebral blood flow was lower after sucrose than after water, sucralose, and monk fruit drink 30 minutes after ingestion. This suggests that neural activity in that region of the brain was lower after ingesting the sucrose-sweetened drink than after water, and drinks sweetened with sucralose and monk fruit extract.
Exploratory analyses showed increased cerebral blood flow (and thus increased neural activity) after consumption of the allulose+stevia-sweetened drink in the amygdala region of the brain and after the stevia-sweetened drink in the putamen region of the brain compared to the sucrose-sweetened drink. Despite its low energy content, the allulose+stevia-sweetened drink delayed gastric emptying (the speed at which food leaves the stomach) similar to the sucrose-sweetened drink, whereas only the sucrose-sweetened drink increased glucose and insulin concentrations.
This particular finding stood out to the research team. The fact that the “LNCS allulose slowed down stomach emptying of the drink similar to table sugar despite its low energy content” was a surprising result, Smeets said. Looking ahead, he added, “I would like to further explore allulose, e.g. by measuring its effect on gut hormones that affect gastric emptying and appetite, like GLP-1.”
“Although flavored waters with LNCS mostly elicit similar neural and gastrointestinal responses as water, they have some distinct effects on the brain compared with 25 g of sucrose, particularly in reward-related brain areas,” the study authors wrote.
Smeets emphasized that the overarching takeaway for consumers is quite straightforward: “Sweet drinks (flavored waters) with LNCS mostly elicit similar neural and gastrointestinal responses as water, i.e., they are largely equivalent to water except for their sweet taste.”
The study contributes to the scientific knowledge about brain reactions to sweetened beverages. However, it should be noted that the study was conducted on a very small group of participants, which may have made some differences in brain reactions undetectable using usual statistical procedures. Smeets also pointed out that the research involved a “young healthy adults (specifically selected),” cautioning that “responses in individuals with overweight/obesity or type 2 diabetes might be different.”
The paper, “Brain and physiological responses to flavored waters with different sweeteners: a randomized crossover study in healthy young adults,” was authored by Paul AM Smeets, Ralf Veit, Els Oosterink, Saskia Meijboom, Davide Risso, Hubert Preissl, and Stephanie Kullmann.
(Note: This article was updated post-publication with comments from Smeets.)
-------------------------------------------------
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#psychology #counseling #socialwork #psychotherapy @psychotherapist @psychotherapists @psychology @socialpsych @socialwork @psychiatry #mentalhealth #psychiatry #healthcare #depression #psychotherapist #BrainImaging #Sweeteners #SucroseVsLNCS #RewardCircuit #VentralTegmentalArea #Hypothalamus #FlavorBevResearch #NeuroscienceNutrition #AlluloseStevia #GutBrainConnection
-
DATE: September 22, 2026 at 02:30PM
SOURCE: PSYPOST.ORG** Research quality varies widely from fantastic to small exploratory studies. Please check research methods when conclusions are very important to you. **
-------------------------------------------------TITLE: Brain scans reveal how artificial sweeteners affect our reward circuits differently than sugar
An experimental study compared changes in brain activity after ingestion of water and different types of flavored waters. Results showed that cerebral blood flow in the hypothalamus (a brain region that controls homeostatic processes like hunger and thirst) was not differentially affected by any of the drinks. However, the ventral tegmental area (a midbrain region involved in reward and motivation) showed lower changes in cerebral blood flow after sucrose than after water, sucralose, or monk fruit drink ingestion. The paper was published in The American Journal of Clinical Nutrition.
As obesity rates have risen worldwide, reducing excessive energy intake has become an important goal for both individuals and public health. One widely used strategy is to replace sugar with low- or no-calorie sweeteners, particularly in beverages, where added sugars can contribute substantially to daily calorie intake. Although concerns are often raised that exposure to sweetness might increase cravings for sweet foods, current evidence does not consistently support this idea.
At the same time, low- and no-calorie sweeteners should not necessarily be viewed as a single, uniform group. Different sweeteners can vary in taste, metabolic effects, effects on the gut microbiome, and the physiological responses they produce after consumption. Sugars themselves also differ in how they are processed by the body and in their effects on blood glucose and other metabolic processes.
Because the brain plays a central role in hunger, satiety, reward, and energy regulation, researchers are increasingly interested in how different sweeteners influence brain activity after consumption. Brain-imaging research suggests that caloric sugars and non-caloric sweeteners may sometimes produce different responses in regions involved in appetite regulation, including the hypothalamus, although findings remain inconsistent.
Study author Paul AM Smeets, an associate professor at the Division of Human Nutrition and Health at Wageningen University Research, and his colleagues conducted a study in which they examined changes in brain activity and physiological markers after the ingestion of flavored waters sweetened with the sugar sucrose or various low-no-calorie sweeteners.
“I have done previous work on low-/no-calorie sweeteners (LNCS), also with the use of brain imaging (fMRI),” Smeets explained. “There has been quite some negative press about potential adverse effects of sweet compounds on metabolism and energy intake. The evidence in favor of no adverse effects such as subsequent increased food intake is substantial. That said, there is research emerging that shows differential effects of different LNCS because they are metabolized differently by the body. Therefore, when I was approached by an ingredient company to do a study on a range of LNCS I was eager to pursue such a study.”
The researchers hypothesized that sugar sucrose would elicit decreased cerebral blood flow (indicating decreased neural activity) in brain areas related to food intake regulation and reward 30 minutes after ingestion. They expected that low- or no-calorie sweeteners and water would not produce such effects due to their low or absent energy content.
Study participants were 30 healthy individuals. Fifteen of them were men. Their average age was 23 years. They completed six treatment sessions between February 2023 and March 2024.
The treatment consisted of ingestion of 500 milliliters of either water or one of five equally sweet, lemon-lime flavored waters sweetened with sucrose (25 grams, 97 kcal) or sucralose, stevia extract, monk fruit extract, or allulose + stevia extract.
Sucralose is a high-intensity artificial sweetener made from modified sucrose that provides sweetness with virtually no calories. Stevia extract is a plant-derived sweetener obtained from Stevia rebaudiana and contains sweet compounds called steviol glycosides. Monk fruit extract is a natural high-intensity sweetener derived from Siraitia grosvenorii fruit. Allulose is a rare low-calorie sugar with properties similar to ordinary sugar. Stevia is mixed with allulose to increase sweetness while keeping calorie content low. These sweeteners add little or no calories to a drink.
At the start of the treatment procedure, participants completed magnetic resonance imaging scans of their brains and of their stomachs. They also answered questions about appetite and well-being verbally. After this, they drank the drink assigned to them on the occasion. This was followed by two more scans of their brains and of their stomachs at different times up to 45 minutes after drinking.
Participants gave blood samples at the start and five more times up to an hour after drinking their assigned beverage (except on the day they received water). After the first sip, participants rated the tastiness and sweetness of the drink they consumed. All participants consumed their drinks within five minutes. Sixty minutes after drinking, after all the procedures were completed, participants were offered a takeaway breakfast.
“It was a huge study, with approximately 180 intense test sessions that combined brain imaging, blood sampling and stomach imaging,” Smeets noted. “I’m really proud of the research team that did the data collection.”
Results showed that all sweet drinks were liked equally, except monk fruit, which was liked modestly less than the sucrose-sweetened drink. All sweetened drinks except the one with monk fruit were liked more than water. All sweetened drinks were perceived as sweeter than water. The monk fruit-sweetened drink and the drink sweetened with allulose+stevia were rated modestly less sweet than the sucrose-sweetened drink.
Cerebral blood flow in the hypothalamus was similarly affected by all sweet drinks. Cerebral blood flow is an indirect indicator of activity in a particular region of the brain, with higher cerebral blood flow generally suggesting higher neural activity.
In the ventral tegmental area, the change in the cerebral blood flow was lower after sucrose than after water, sucralose, and monk fruit drink 30 minutes after ingestion. This suggests that neural activity in that region of the brain was lower after ingesting the sucrose-sweetened drink than after water, and drinks sweetened with sucralose and monk fruit extract.
Exploratory analyses showed increased cerebral blood flow (and thus increased neural activity) after consumption of the allulose+stevia-sweetened drink in the amygdala region of the brain and after the stevia-sweetened drink in the putamen region of the brain compared to the sucrose-sweetened drink. Despite its low energy content, the allulose+stevia-sweetened drink delayed gastric emptying (the speed at which food leaves the stomach) similar to the sucrose-sweetened drink, whereas only the sucrose-sweetened drink increased glucose and insulin concentrations.
This particular finding stood out to the research team. The fact that the “LNCS allulose slowed down stomach emptying of the drink similar to table sugar despite its low energy content” was a surprising result, Smeets said. Looking ahead, he added, “I would like to further explore allulose, e.g. by measuring its effect on gut hormones that affect gastric emptying and appetite, like GLP-1.”
“Although flavored waters with LNCS mostly elicit similar neural and gastrointestinal responses as water, they have some distinct effects on the brain compared with 25 g of sucrose, particularly in reward-related brain areas,” the study authors wrote.
Smeets emphasized that the overarching takeaway for consumers is quite straightforward: “Sweet drinks (flavored waters) with LNCS mostly elicit similar neural and gastrointestinal responses as water, i.e., they are largely equivalent to water except for their sweet taste.”
The study contributes to the scientific knowledge about brain reactions to sweetened beverages. However, it should be noted that the study was conducted on a very small group of participants, which may have made some differences in brain reactions undetectable using usual statistical procedures. Smeets also pointed out that the research involved a “young healthy adults (specifically selected),” cautioning that “responses in individuals with overweight/obesity or type 2 diabetes might be different.”
The paper, “Brain and physiological responses to flavored waters with different sweeteners: a randomized crossover study in healthy young adults,” was authored by Paul AM Smeets, Ralf Veit, Els Oosterink, Saskia Meijboom, Davide Risso, Hubert Preissl, and Stephanie Kullmann.
(Note: This article was updated post-publication with comments from Smeets.)
-------------------------------------------------
Private, vetted email list for mental health professionals: https://www.clinicians-exchange.org
Unofficial Psychology Today Xitter to toot feed at Psych Today Unofficial Bot @PTUnofficialBot
-------------------------------------------------
#psychology #counseling #socialwork #psychotherapy @psychotherapist @psychotherapists @psychology @socialpsych @socialwork @psychiatry #mentalhealth #psychiatry #healthcare #depression #psychotherapist #BrainImaging #Sweeteners #SucroseVsLNCS #RewardCircuit #VentralTegmentalArea #Hypothalamus #FlavorBevResearch #NeuroscienceNutrition #AlluloseStevia #GutBrainConnection
-
DATE: September 22, 2026 at 02:30PM
SOURCE: PSYPOST.ORG** Research quality varies widely from fantastic to small exploratory studies. Please check research methods when conclusions are very important to you. **
-------------------------------------------------TITLE: Brain scans reveal how artificial sweeteners affect our reward circuits differently than sugar
An experimental study compared changes in brain activity after ingestion of water and different types of flavored waters. Results showed that cerebral blood flow in the hypothalamus (a brain region that controls homeostatic processes like hunger and thirst) was not differentially affected by any of the drinks. However, the ventral tegmental area (a midbrain region involved in reward and motivation) showed lower changes in cerebral blood flow after sucrose than after water, sucralose, or monk fruit drink ingestion. The paper was published in The American Journal of Clinical Nutrition.
As obesity rates have risen worldwide, reducing excessive energy intake has become an important goal for both individuals and public health. One widely used strategy is to replace sugar with low- or no-calorie sweeteners, particularly in beverages, where added sugars can contribute substantially to daily calorie intake. Although concerns are often raised that exposure to sweetness might increase cravings for sweet foods, current evidence does not consistently support this idea.
At the same time, low- and no-calorie sweeteners should not necessarily be viewed as a single, uniform group. Different sweeteners can vary in taste, metabolic effects, effects on the gut microbiome, and the physiological responses they produce after consumption. Sugars themselves also differ in how they are processed by the body and in their effects on blood glucose and other metabolic processes.
Because the brain plays a central role in hunger, satiety, reward, and energy regulation, researchers are increasingly interested in how different sweeteners influence brain activity after consumption. Brain-imaging research suggests that caloric sugars and non-caloric sweeteners may sometimes produce different responses in regions involved in appetite regulation, including the hypothalamus, although findings remain inconsistent.
Study author Paul AM Smeets, an associate professor at the Division of Human Nutrition and Health at Wageningen University Research, and his colleagues conducted a study in which they examined changes in brain activity and physiological markers after the ingestion of flavored waters sweetened with the sugar sucrose or various low-no-calorie sweeteners.
“I have done previous work on low-/no-calorie sweeteners (LNCS), also with the use of brain imaging (fMRI),” Smeets explained. “There has been quite some negative press about potential adverse effects of sweet compounds on metabolism and energy intake. The evidence in favor of no adverse effects such as subsequent increased food intake is substantial. That said, there is research emerging that shows differential effects of different LNCS because they are metabolized differently by the body. Therefore, when I was approached by an ingredient company to do a study on a range of LNCS I was eager to pursue such a study.”
The researchers hypothesized that sugar sucrose would elicit decreased cerebral blood flow (indicating decreased neural activity) in brain areas related to food intake regulation and reward 30 minutes after ingestion. They expected that low- or no-calorie sweeteners and water would not produce such effects due to their low or absent energy content.
Study participants were 30 healthy individuals. Fifteen of them were men. Their average age was 23 years. They completed six treatment sessions between February 2023 and March 2024.
The treatment consisted of ingestion of 500 milliliters of either water or one of five equally sweet, lemon-lime flavored waters sweetened with sucrose (25 grams, 97 kcal) or sucralose, stevia extract, monk fruit extract, or allulose + stevia extract.
Sucralose is a high-intensity artificial sweetener made from modified sucrose that provides sweetness with virtually no calories. Stevia extract is a plant-derived sweetener obtained from Stevia rebaudiana and contains sweet compounds called steviol glycosides. Monk fruit extract is a natural high-intensity sweetener derived from Siraitia grosvenorii fruit. Allulose is a rare low-calorie sugar with properties similar to ordinary sugar. Stevia is mixed with allulose to increase sweetness while keeping calorie content low. These sweeteners add little or no calories to a drink.
At the start of the treatment procedure, participants completed magnetic resonance imaging scans of their brains and of their stomachs. They also answered questions about appetite and well-being verbally. After this, they drank the drink assigned to them on the occasion. This was followed by two more scans of their brains and of their stomachs at different times up to 45 minutes after drinking.
Participants gave blood samples at the start and five more times up to an hour after drinking their assigned beverage (except on the day they received water). After the first sip, participants rated the tastiness and sweetness of the drink they consumed. All participants consumed their drinks within five minutes. Sixty minutes after drinking, after all the procedures were completed, participants were offered a takeaway breakfast.
“It was a huge study, with approximately 180 intense test sessions that combined brain imaging, blood sampling and stomach imaging,” Smeets noted. “I’m really proud of the research team that did the data collection.”
Results showed that all sweet drinks were liked equally, except monk fruit, which was liked modestly less than the sucrose-sweetened drink. All sweetened drinks except the one with monk fruit were liked more than water. All sweetened drinks were perceived as sweeter than water. The monk fruit-sweetened drink and the drink sweetened with allulose+stevia were rated modestly less sweet than the sucrose-sweetened drink.
Cerebral blood flow in the hypothalamus was similarly affected by all sweet drinks. Cerebral blood flow is an indirect indicator of activity in a particular region of the brain, with higher cerebral blood flow generally suggesting higher neural activity.
In the ventral tegmental area, the change in the cerebral blood flow was lower after sucrose than after water, sucralose, and monk fruit drink 30 minutes after ingestion. This suggests that neural activity in that region of the brain was lower after ingesting the sucrose-sweetened drink than after water, and drinks sweetened with sucralose and monk fruit extract.
Exploratory analyses showed increased cerebral blood flow (and thus increased neural activity) after consumption of the allulose+stevia-sweetened drink in the amygdala region of the brain and after the stevia-sweetened drink in the putamen region of the brain compared to the sucrose-sweetened drink. Despite its low energy content, the allulose+stevia-sweetened drink delayed gastric emptying (the speed at which food leaves the stomach) similar to the sucrose-sweetened drink, whereas only the sucrose-sweetened drink increased glucose and insulin concentrations.
This particular finding stood out to the research team. The fact that the “LNCS allulose slowed down stomach emptying of the drink similar to table sugar despite its low energy content” was a surprising result, Smeets said. Looking ahead, he added, “I would like to further explore allulose, e.g. by measuring its effect on gut hormones that affect gastric emptying and appetite, like GLP-1.”
“Although flavored waters with LNCS mostly elicit similar neural and gastrointestinal responses as water, they have some distinct effects on the brain compared with 25 g of sucrose, particularly in reward-related brain areas,” the study authors wrote.
Smeets emphasized that the overarching takeaway for consumers is quite straightforward: “Sweet drinks (flavored waters) with LNCS mostly elicit similar neural and gastrointestinal responses as water, i.e., they are largely equivalent to water except for their sweet taste.”
The study contributes to the scientific knowledge about brain reactions to sweetened beverages. However, it should be noted that the study was conducted on a very small group of participants, which may have made some differences in brain reactions undetectable using usual statistical procedures. Smeets also pointed out that the research involved a “young healthy adults (specifically selected),” cautioning that “responses in individuals with overweight/obesity or type 2 diabetes might be different.”
The paper, “Brain and physiological responses to flavored waters with different sweeteners: a randomized crossover study in healthy young adults,” was authored by Paul AM Smeets, Ralf Veit, Els Oosterink, Saskia Meijboom, Davide Risso, Hubert Preissl, and Stephanie Kullmann.
(Note: This article was updated post-publication with comments from Smeets.)
-------------------------------------------------
Private, vetted email list for mental health professionals: https://www.clinicians-exchange.org
Unofficial Psychology Today Xitter to toot feed at Psych Today Unofficial Bot @PTUnofficialBot
-------------------------------------------------
#psychology #counseling #socialwork #psychotherapy @psychotherapist @psychotherapists @psychology @socialpsych @socialwork @psychiatry #mentalhealth #psychiatry #healthcare #depression #psychotherapist #BrainImaging #Sweeteners #SucroseVsLNCS #RewardCircuit #VentralTegmentalArea #Hypothalamus #FlavorBevResearch #NeuroscienceNutrition #AlluloseStevia #GutBrainConnection