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Published on: April 28, 2016
Ghrelin, peptide YY and their hypothalamic targets differentially regulate spontaneous physical activity
Paul T Pfluger1, Tamara R Castañeda, Kristy M Heppner
1Obesity Research Center, Dept. of Internal Medicine, University of Cincinnati, Cincinnati, OH, USA. paul.pfluger@uc.edu
Physiology & Behavior
|May 11, 2011
Summary
Gut hormones like ghrelin influence spontaneous physical activity (SPA), impacting energy balance. These hormones and their brain targets may play a key role in regulating body weight and activity levels.
Area of Science:
- Neuroendocrinology
- Behavioral Neuroscience
- Physiology
Background:
- Spontaneous physical activity (SPA) regulation is linked to neuroendocrine circuits controlling food intake.
- Gut-brain communication via hormones like ghrelin and PYY may influence energy balance and activity.
Purpose of the Study:
- To investigate the long-term and acute effects of ghrelin, PYY 3-36, and hypothalamic neuropeptides (NPY, AgRP, POMC) on rat locomotor activity and home cage behaviors.
- To elucidate the role of endocrine gut-brain signaling in the control of SPA and energy balance.
Main Methods:
- Utilized an automated infrared beam break system for SPA analysis.
- Employed a novel automated video-based behavior analysis system (HomeCageScan - HCS).
- Administered gastrointestinal hormones and neuropeptides chronically and acutely via peripheral and central routes in rats.
Main Results:
- Chronic ghrelin infusion increased body weight and fat mass, primarily by decreasing SPA, not increasing caloric intake.
- Central ghrelin, AgRP, and NPY modulated SPA, with NPY showing a transient increase and AgRP a delayed decrease.
- Acute alpha-MSH decreased food intake but not SPA, while PYY 3-36 transiently increased SPA.
Conclusions:
- Gut hormones and their hypothalamic targets significantly influence spontaneous physical activity.
- SPA regulation by these neuroendocrine pathways is a critical component of energy balance regulation.
- Findings highlight a novel mechanism linking gut-brain communication to physical activity and metabolic control.
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