Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New role for insulin: Studies tie the hormone to brain's 'pleasure' center

27.10.2015

Findings also shed light on food choices and obesity

Insulin, the hormone essential to all mammals for controlling blood sugar levels and a feeling of being full after eating, plays a much stronger role than previously known in regulating release of dopamine, a neurotransmitter that helps control the brain's reward and pleasure centers, new studies by researchers at NYU Langone Medical Center show.


Image of a rodent brain cell, with insulin receptors (seen as many green dots) that when activated spur release of dopamine (In background in pink is neuron nucleus.)

Courtesy of Nature Communications

"We found that when there's more insulin in the brain, there will be more dopamine released, not less," says study senior investigator and NYU Langone neuroscientist Margaret Rice, PhD. Her team's new findings from laboratory and behavioral studies with rodents are set to appear in the journal Nature Communications online Oct. 27.

Rice says the experiments she and her colleagues conducted not only reaffirm that insulin helps trigger the reuptake of dopamine when insulin levels rise, but also are the first to show that the net effect is a rise in dopamine levels. The results may also be the first to demonstrate that insulin's role in the dopamine pathway may affect and explain food choices.

In one set of experiments, Rice and her colleagues recorded a 20 percent to 55 percent increase in dopamine released in the striatal region of the rodent brain (where dopamine's effects on the brain are felt and which governs the body's response to getting a reward). The rise occurred along the same timeframe as the rise in insulin activity needed to process any food sugars the mice and rats ate. And this occurred despite the reabsorption, or reuptake, of dopamine that in other regions of the brain tells an animal that its appetite is satisfied.

Rice and study co-principal investigator Kenneth Carr, PhD, also conducted separate experiments with rats in which they found that animals fed low-calorie diets had a 10-fold greater sensitivity to increasing insulin levels in the brain (meaning that it took only a tenth of a rise in insulin levels as seen in rats on a normal diet to spur dopamine release). By contrast, rats on high-calorie diets lost all striatal-brain insulin responsiveness. In addition, rats offered a choice between a drink reward that was paired with either an insulin antibody injection to block hormone signaling or a mock placebo injection always favored the drink-injection combination that led to intact insulin signaling (and more dopamine).

"Our work establishes what we believe is a new role for insulin as part of the brain's reward system and suggests that rodents, and presumably people, may choose to consume high-carb or low-fat meals that release more insulin - all to heighten dopamine release," says Rice, a professor in the Department of Neurosurgery at NYU Langone and a member of NYU Langone's Druckenmiller Neuroscience Institute.

Rice says this finding is important because chronically elevated insulin levels and lowered insulin sensitivity in the brain are closely tied to obesity and type II diabetes, both very prevalent in the United States.

Rice says the team plans further experiments on how insulin influences the mammalian brain's control over food motivation and reward pathways, and whether changes in insulin sensitivity brought about by obesity can be reversed or even prevented.

"If our future experiments prove successful," says Rice, "it could confirm our hypothesis that when people refer to an insulin-glucose rush, they may really be referring to a dopamine reward rush. And there are healthy ways to get that by making smart food choices."

###

Funding support for the research was provided by grants from the National Institute on Drug Abuse and the National Institute of Neurological Disorders and Stroke, both members of the National Institutes of Health. Corresponding grant numbers are R01 DA033811, a multiple-principal investigator award; R01 DA03956; and R01 NS036362. Additional funding support came from a Brain and Behavior Research Institute NARSAD independent investigator award.

Besides Rice and Carr, other NYU Langone researchers involved in the study were lead study investigator Melissa Stouffer, PhD; Catherine Woods, BA; Jyoti Patel, PhD; Christian Lee, PhD; Paul Whitkovsky, PhD; Li Bao, PhD; Robert Machold, PhD; Kymry Jones, PhD; Soledad Cabeza de Vaca, PhD; and Maarten Reith, PhD.

Media Inquiries:

David March
Phone: 212-404-3528
david.march@nyumc.org

Media Contact

David March
david.march@nyumc.org
212-404-3528

 @NYULMC

http://www.med.nyu.edu 

David March | EurekAlert!

Further reports about: Institute Langone Medicine dopamine food choices hormone rise

More articles from Health and Medicine:

nachricht Cholesterol-lowering drugs may fight infectious disease
22.08.2017 | Duke University

nachricht Once invincible superbug squashed by 'superteam' of antibiotics
22.08.2017 | University at Buffalo

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>