Studying Activity of "Deprivation Neurons" Could Help to Explain Why Dieting Is So Hard – Genetic Engineering & Biotechnology News
Research in engineered mice by scientists at Beth Israel Deaconess Medical Center (BIDMC) has revealed new insights into the complex interplay among neurons that govern hunger, behavior and learning, which could ultimately help to shed light on what happens in some eating disorders.
Our discovery provides the answer to this important question of how we learn to seek and consume food and how hunger enhances the learning of tasks oriented towards acquiring food, said research lead Bradford B. Lowell, MD, PhD, of the Division of Endocrinology at BIDMC, who is also a professor of medicine at Harvard Medical School. With additional work, our discovery could ultimately shed light into what goes wrong in disorders of hunger such as obesity and anorexia nervosa.
Lowell and colleagues report on their findings in Nature, in a paper titled, Food cue regulation of AgRP hunger neurons guides learning.
The BIDMC team has been at the forefront of research to identify the small population of agouti-related peptide (AgRP)-expressing neurons that are found in the hypothalamus. These neurons are activated by fasting, which causes the sensation of hunger, as an aversive state that motivates the seeking and consumption of food, the authors explained. Eating returns AGRP neuron activity towards baseline on three distinct timescales: rapidly and transiently following sensory detection of food cues, slowly and longer-lasting in response to nutrients in the gut, and even more slowly and permanently with restoration of energy balance. However, the team continued, precisely how the AGRP cells and the unpleasant feeling of hunger they cause actually motivate an animal to find food and eat hasnt been understood.
To try and answer this longstanding question, the BIDMC team turned to their engineered mouse model to investigate AgRP neuronal activity. The mouse modelon which more than 100 scientific papers have been publishedallows researchers to switch AgRP neurons on and off, determine what activates or inactivates them, and map their connections to other regions of the brain.
Using this model, we and others discovered some time ago that these neurons are turned on by fasting, causing hunger, and that artificially turning them on in a recently fed mouse that otherwise would not eat, causes huge amounts of food to be eaten, as if the mouse had not eaten in days, commented first author Janet Berrios, PhD, a postdoctoral fellow at BIDMC. In fact, just the presence of food or a cue linked to the presence of food will instantaneously inhibit the neurons activity, easing the unpleasant hunger sensation. If food isnt eaten in a short period of time, however, neuronal activity rebounds, restoring hunger to its previous levels.
For their newly reported study the team trained the engineered mice to recognize a food cue by associating a light with access to food, just as a dog can be trained to associate the sound of a cupboard opening with getting a biscuit. The team was then able to observe how various levels of hunger and the presence of the food cues affected the AgRP neurons.
As they expected, they observed that fasting activated the AgRP neurons, and food cues in the environment workvia a network of neurons elsewhere in the brainto inhibit AgRP activity. But remarkably, when the team blocked off this network, it caused the mice to have great difficulty learning a task in which sensory cues related to food were used to guide acquisition of food. Interference with this circuit impairs food cue inhibition of AGRP neurons and, notably, greatly impairs learning of a sensory cue-initiated food-acquisition task, the team noted. This is specific for food, as learning of an identical water-acquisition task is unaffected.
From this, the researchers suggest that fasting or deprivation known to activate the AgRP neurons and the feeling of hunger causes an unpleasant, or aversive, feeling. When food cues in the environment inhibit AgRP activity, it also tamps down the aversive feeling, which in turn serves as a reward powerful enough to enhance learning.
Calorific deficiency activates AGRP neurons and this causes the aversive feeling of hunger, they wrote. Environmental cues that are instructive for food acquisition then engage a particular neuronal circuit that transiently reduces the AGRP neuronal activity. As AGRP neurons have been proposed to transmit a negative-valence teaching signal, these appetitive falls in aversive AGRP neuron activity, over time, increase the incentive salience of food cues, thereby facilitating the learning of food acquisitions tasks, the team proposed.
Its as if these rewarding, sensory cue-linked drops in unpleasant AgRP neuron activity push the mouse towards environmental cues and tasks associated with obtaining food, said Lowell, who noted that thirst likely works the same way, although through a different specialized set of neurons. An obvious implication of this idea is that it explains why dieting is so difficultdieters are perpetually stuck with this aversive feeling. So, in short, it appears that we eat and drink because weve learned that this reduces the activity of these deprivation neurons, and hence the linked bad feelings.
- Cindy Crawford: 'In the '90s People Thought a Big Bowl of Pasta Was Low-Calorie' [Last Updated On: October 11th, 2014] [Originally Added On: October 11th, 2014]
- In 1990s people thought pasta was low-calorie: Cindy Crawford [Last Updated On: October 11th, 2014] [Originally Added On: October 11th, 2014]
- Healthy Weight Loss & Dieting Tips: How to Lose Weight and ... [Last Updated On: October 11th, 2014] [Originally Added On: October 11th, 2014]
- Dieting - Wikipedia, the free encyclopedia [Last Updated On: October 11th, 2014] [Originally Added On: October 11th, 2014]
- Cutting with Elliot: Full Day of Flexible Dieting IN COLLEGE - REFEED EDITION - IIFYM - Ep.16 - Video [Last Updated On: October 11th, 2014] [Originally Added On: October 11th, 2014]
- DO YOU JUDGE YOURSELF IF YOU'RE NOT DIETING? - Video [Last Updated On: October 11th, 2014] [Originally Added On: October 11th, 2014]
- Flexible Dieting Q and A - Part 1 - Video [Last Updated On: October 11th, 2014] [Originally Added On: October 11th, 2014]
- Elliot Fitnes Q&A - Reverse Dieting, Future Goals, and Competing? - Video [Last Updated On: October 11th, 2014] [Originally Added On: October 11th, 2014]
- Why Can't I Lose Weight Eating Healthy: Healthy Dieting May Slow Weight Loss - Video [Last Updated On: October 11th, 2014] [Originally Added On: October 11th, 2014]
- Dieting - Ep. 19 | As We Proceed - Video [Last Updated On: October 11th, 2014] [Originally Added On: October 11th, 2014]
- The Deal With Diets - KidsHealth [Last Updated On: October 13th, 2014] [Originally Added On: October 13th, 2014]
- Post Competition Dieting - Video [Last Updated On: October 13th, 2014] [Originally Added On: October 13th, 2014]
- Why dieting doesnt work [Last Updated On: October 14th, 2014] [Originally Added On: October 14th, 2014]
- Crash dieting IS the best way to loose weight, say experts [Last Updated On: October 15th, 2014] [Originally Added On: October 15th, 2014]
- Crash-dieting more effective that gradual weight loss, study suggests [Last Updated On: October 16th, 2014] [Originally Added On: October 16th, 2014]
- Losing weight quickly is just as good (or bad) as losing it gradually [Last Updated On: October 16th, 2014] [Originally Added On: October 16th, 2014]
- Crash-dieting more effective than gradual weight loss, study suggests [Last Updated On: October 16th, 2014] [Originally Added On: October 16th, 2014]
- The Geordie Motivator on Dieting - Video [Last Updated On: October 16th, 2014] [Originally Added On: October 16th, 2014]
- SAVING YOUR DIETING MACRO'S TO EAT JUNK FOOD & CRAP: IFBB BIKINI PRO - Video [Last Updated On: October 18th, 2014] [Originally Added On: October 18th, 2014]
- HOW TO MAKE DIETING EASIER - Video [Last Updated On: October 19th, 2014] [Originally Added On: October 19th, 2014]
- Flexible Dieting Q and A - Part 2 - Video [Last Updated On: October 19th, 2014] [Originally Added On: October 19th, 2014]
- Calories VS. Food Volume - The Secret To Successful Dieting - Video [Last Updated On: October 20th, 2014] [Originally Added On: October 20th, 2014]
- How to Stop Yo-Yo Dieting For Good - Video [Last Updated On: October 20th, 2014] [Originally Added On: October 20th, 2014]
- Dieting How to Do an Isagenix Shake Day - Video [Last Updated On: October 21st, 2014] [Originally Added On: October 21st, 2014]
- Donna Noble ~ "But I've been dieting" (HUMOUR) - Video [Last Updated On: October 21st, 2014] [Originally Added On: October 21st, 2014]
- Q&A with Sohee episode 2: revelations with flexible dieting - Video [Last Updated On: October 22nd, 2014] [Originally Added On: October 22nd, 2014]
- Dieting For People Who FEEL Too much - Video [Last Updated On: October 23rd, 2014] [Originally Added On: October 23rd, 2014]
- IIFYM Day of Eating Ep5 Chili Cheese Fries, 1400 calories, flexible dieting - Video [Last Updated On: October 23rd, 2014] [Originally Added On: October 23rd, 2014]
- Dr. Oz Show Schedule 10/22/2014: Ending Yo-Yo Dieting Weight Loss Traps - Video [Last Updated On: October 25th, 2014] [Originally Added On: October 25th, 2014]
- Does Flexible Dieting Work? IFBB Pro opinion - Video [Last Updated On: October 27th, 2014] [Originally Added On: October 27th, 2014]
- Full Day Of Eating IIFYM Flexible Dieting - Video [Last Updated On: October 29th, 2014] [Originally Added On: October 29th, 2014]
- Common Sense Dieting Tip! - Video [Last Updated On: October 31st, 2014] [Originally Added On: October 31st, 2014]
- Flexible dieting Grocery shopping run - Video [Last Updated On: November 2nd, 2014] [Originally Added On: November 2nd, 2014]
- Dieting Tips: Avoid This #1 Mistake If You Want To Lose Weight - Video [Last Updated On: November 3rd, 2014] [Originally Added On: November 3rd, 2014]
- Most important item to have while dieting - Video [Last Updated On: November 3rd, 2014] [Originally Added On: November 3rd, 2014]
- No Dieting Thanksgiving Day 2014 Metro Detroit Boot Camp Burns Thousands of Calories Eat Anything - Video [Last Updated On: November 4th, 2014] [Originally Added On: November 4th, 2014]
- IceCream4PRs Podcast 2 - Donuts, Post-Show Feels, Reverse Dieting - Video [Last Updated On: November 4th, 2014] [Originally Added On: November 4th, 2014]
- Liposuction. Take off what dieting wont! - Video [Last Updated On: November 4th, 2014] [Originally Added On: November 4th, 2014]
- Cutting with Elliot: Full Day of Flexible Dieting Ep. 19 IIFYM (Natural Teen Bodybuilding College) - Video [Last Updated On: November 5th, 2014] [Originally Added On: November 5th, 2014]
- Here I will teach you how to pronounce 'dieting' with Zira.mp4 - Video [Last Updated On: November 5th, 2014] [Originally Added On: November 5th, 2014]
- Interview with Sohee Lee on metabolic adaptation, reverse dieting, and more... - Video [Last Updated On: November 7th, 2014] [Originally Added On: November 7th, 2014]
- Full Day of Flexible Dieting IIFYM IN COLLEGE Ep.20 (Being Basic) - Video [Last Updated On: November 9th, 2014] [Originally Added On: November 9th, 2014]
- Reverse Dieting: Tips & IIFYM Grocery Pickups - Video [Last Updated On: November 10th, 2014] [Originally Added On: November 10th, 2014]
- Kevin Van Voris-Full day of Flexible Dieting #2 - Video [Last Updated On: November 10th, 2014] [Originally Added On: November 10th, 2014]
- Full Day of IIFYM #17 Reverse Dieting - Video [Last Updated On: November 11th, 2014] [Originally Added On: November 11th, 2014]
- How To Balance Dieting and Social Life | FitnGeeky QnA - Video [Last Updated On: November 11th, 2014] [Originally Added On: November 11th, 2014]
- Lets Play the Sims 4 [Part 23]- Dieting - Video [Last Updated On: November 11th, 2014] [Originally Added On: November 11th, 2014]
- Drew Barrymore Has No Interest in Dieting - Video [Last Updated On: November 12th, 2014] [Originally Added On: November 12th, 2014]
- Full Day Of Eating IIFYM Flexible Dieting 2 - Video [Last Updated On: November 12th, 2014] [Originally Added On: November 12th, 2014]
- Top 10 Ways to Lose Weight Fast Without Dieting - Video [Last Updated On: November 14th, 2014] [Originally Added On: November 14th, 2014]
- Dieting just got easier - Video [Last Updated On: November 16th, 2014] [Originally Added On: November 16th, 2014]
- Almost a Full Day of Flexible Dieting - Video [Last Updated On: November 17th, 2014] [Originally Added On: November 17th, 2014]
- Post Bodybuilding Contest: Reverse Dieting - Video [Last Updated On: November 18th, 2014] [Originally Added On: November 18th, 2014]
- Cutting with Elliot - Full Day of Flexible Dieting IIFYM in College - Ep. 21 - Video [Last Updated On: November 19th, 2014] [Originally Added On: November 19th, 2014]
- Exercise and Dieting - Video [Last Updated On: November 19th, 2014] [Originally Added On: November 19th, 2014]
- IIFYM/ Flexible dieting/ IF Day Of Eating EP.1 - Video [Last Updated On: November 19th, 2014] [Originally Added On: November 19th, 2014]
- Ogus Chat #1 (Reverse Dieting Controversy, Competing, Etc) - Video [Last Updated On: November 19th, 2014] [Originally Added On: November 19th, 2014]
- Healthy Living Looks at Dieting for Diabetics - Video [Last Updated On: November 21st, 2014] [Originally Added On: November 21st, 2014]
- OpenLine: Holiday Dieting - Video [Last Updated On: November 21st, 2014] [Originally Added On: November 21st, 2014]
- High Fat, High Protein, Medium Carb Bodybuilding Meal Example While Dieting - Video [Last Updated On: November 22nd, 2014] [Originally Added On: November 22nd, 2014]
- The 'Weight Loss' Goal is a Dieting Thing - Gain Health & Fitness VS Lose Weight - Video [Last Updated On: November 22nd, 2014] [Originally Added On: November 22nd, 2014]
- Dieting Websites Let You Make a Healthy Wager on Your Weight Los - Video [Last Updated On: November 23rd, 2014] [Originally Added On: November 23rd, 2014]
- Q&A Part 4: Flexible dieting tips, lifting and cardio, and female training - Video [Last Updated On: November 24th, 2014] [Originally Added On: November 24th, 2014]
- The "Dark Side" of Dieting and Fitness Modelling - Video [Last Updated On: November 25th, 2014] [Originally Added On: November 25th, 2014]
- IIFYM Day of Eating - Flexible Dieting - Day 9 - Video [Last Updated On: November 26th, 2014] [Originally Added On: November 26th, 2014]
- Peter Brooks Does a Commercial for All in One XS Dieting Pills - Video [Last Updated On: November 26th, 2014] [Originally Added On: November 26th, 2014]
- Dieting Makes you FAT - Video [Last Updated On: November 27th, 2014] [Originally Added On: November 27th, 2014]
- Fat Loss Transformation - Part 2 - Flexible Dieting - Video [Last Updated On: November 27th, 2014] [Originally Added On: November 27th, 2014]
- Is dieting necessary post weight loss surgery? CODS nutrition team answers - Video [Last Updated On: November 29th, 2014] [Originally Added On: November 29th, 2014]
- Holiday Detox and Dieting CHTV Episode 42 - Video [Last Updated On: December 1st, 2014] [Originally Added On: December 1st, 2014]
- Full day of eating 6 - IIFYM - Flexible eating/dieting? - Video [Last Updated On: December 2nd, 2014] [Originally Added On: December 2nd, 2014]
- IIFYM - Full Day of Eating - - Flexible Dieting - Day 10 - Video [Last Updated On: December 2nd, 2014] [Originally Added On: December 2nd, 2014]
- Holidays are coming... with Macros & Flexible Dieting - Video [Last Updated On: December 2nd, 2014] [Originally Added On: December 2nd, 2014]
- Biology Documentary on Dieting - Video [Last Updated On: December 2nd, 2014] [Originally Added On: December 2nd, 2014]
- VLOGMAS DAY 2: Rebellious, Dieting, Netflix, Laundry - Video [Last Updated On: December 4th, 2014] [Originally Added On: December 4th, 2014]
- 2015-16 VENUSFACTOR LoseWeight Without Dieting Discover a Slimmer, Sexier, and Healthier You - Video [Last Updated On: December 4th, 2014] [Originally Added On: December 4th, 2014]
- Reverse Dieting Book Sohee Lee | Amazing Reverse Dieting Book Sohee Lee - Video [Last Updated On: December 6th, 2014] [Originally Added On: December 6th, 2014]
- She's DIEting the Gangster - Video [Last Updated On: December 6th, 2014] [Originally Added On: December 6th, 2014]
- The Uplift Movement Flexible Dieting - Video [Last Updated On: December 7th, 2014] [Originally Added On: December 7th, 2014]
- Dieting - with Jane Plan - Video [Last Updated On: December 9th, 2014] [Originally Added On: December 9th, 2014]