Voluntary Wheel Running Exercise Evoked by Food-Restriction Stress Exacerbates Weight Loss of Adolescent Female Rats but Also Promotes Resilience by Enhancing GABAergic Inhibition of Pyramidal Neurons in the Dorsal Hippocampus

Tara G. Chowdhury, Gauri S. Wable, Yi Wen Chen, Kei Tateyama, Irene Yu, Jia Yi Wang, Alex D. Reyes, Chiye Aoki

Research output: Contribution to journalArticle

Abstract

Adolescence is marked by increased vulnerability to mental disorders and maladaptive behaviors, including anorexia nervosa. Food-restriction (FR) stress evokes foraging, which translates to increased wheel running exercise (EX) for caged rodents, a maladaptive behavior, since it does not improve food access and exacerbates weight loss. While almost all adolescent rodents increase EX following FR, some then become resilient by suppressing EX by the second-fourth FR day, which minimizes weight loss. We asked whether GABAergic plasticity in the hippocampus may underlie this gain in resilience. In vitro slice physiology revealed doubling of pyramidal neurons' GABA response in the dorsal hippocampus of food-restricted animals with wheel access (FR + EX for 4 days), but without increase of mIPSC amplitudes. mIPSC frequency increased by 46%, but electron microscopy revealed no increase in axosomatic GABAergic synapse number onto pyramidal cells and only a modest increase (26%) of GABAergic synapse lengths. These changes suggest increase of vesicular release probability and extrasynaptic GABAA receptors and unsilencing of GABAergic synapses. GABAergic synapse lengths correlated with individual's suppression of wheel running and weight loss. These analyses indicate that EX can have dual roles-exacerbate weight loss but also promote resilience to some by dampening hippocampal excitability.

Original languageEnglish (US)
Pages (from-to)4035-4049
Number of pages15
JournalCerebral Cortex
Volume29
Issue number10
DOIs
StatePublished - Sep 13 2019

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Keywords

  • electron microscopy
  • exercise
  • food restriction
  • glutamic acid decarboxylase
  • mIPSC

ASJC Scopus subject areas

  • Cognitive Neuroscience
  • Cellular and Molecular Neuroscience

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