Pretreatment with a CRF antagonist amplifies feeding inhibition induced by fourth ventricular cocaine- and amphetamine-regulated transcript peptide

Ulrika Smedh, Karen A. Scott, Timothy H. Moran

Research output: Contribution to journalArticlepeer-review

Abstract

Background: Pre-treatment with the corticotropin-releasing factor antagonist α-helical CRF9-41 prevents inhibition of gastric emptying by cocaine-and amphetamine-regulated transcript peptide at a dorsal hindbrain level, but its inhibition of sucrose intake is not affected. This is suggestive of separable underlying mechanisms of action in the caudal brainstem for cocaine-and amphetamine-regulated transcript peptide with regard to food intake and gastrointestinal functions. Here we further examine cocaine-and amphetamine-regulated transcript peptide - corticotropin-releasing factor receptor interactions in caudal brainstem controls of solid food intake. Injections of combinations of vehicle, cocaine-and amphetamine-regulated transcript peptide (0.5 μg or 1 μg) or α-helical CRF9-41 were given into the fourth cerebral ventricle of rats. Nocturnal solid food intake was recorded over 22 h. Results: Pre-treatment with α-helical CRF9-41 into the fourth ventricle significantly increased the responsivity to cocaine-and amphetamine-regulated transcript peptide on hypophagia. In a separate control experiment, α-helical CRF9-41 pre-treatment blocked CRF-induced food intake inhibition indicative of its antagonistic effectiveness. Conclusions: We conclude that an endogenous Corticotropin-releasing factor agonist may modulate suppression of food intake caused by cocaine-and amphetamine-regulated transcript peptide at a dorsal hindbrain level in the absence of stress. A potential caudal brainstem mechanism whereby cocaine-and amphetamine-regulated transcript peptide effects on food intake is attenuated via corticotropin-releasing factor receptor activity causing tonic inhibition, is suggested.

Original languageEnglish (US)
Article number11
JournalBMC Neuroscience
Volume20
Issue number1
DOIs
StatePublished - Mar 18 2019

Keywords

  • Dorsal hindbrain
  • Food intake
  • Rat

ASJC Scopus subject areas

  • Neuroscience(all)
  • Cellular and Molecular Neuroscience

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