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Stress‐induced suppression of neuropeptide Y‐induced hunger in anorexic chicks involves corticotrophin‐releasing factor signalling and the paraventricular nucleus of the hypothalamus
Author(s) -
Wang J.,
Yi J.,
Siegel P. B.,
Cline M. A.,
Gilbert E. R.
Publication year - 2017
Publication title -
journal of neuroendocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.062
H-Index - 116
eISSN - 1365-2826
pISSN - 0953-8194
DOI - 10.1111/jne.12555
Subject(s) - endocrinology , medicine , hypothalamus , neuropeptide y receptor , nucleus , neuropeptide , psychology , biology , neuroscience , receptor
The Virginia lines of chickens have been selected for low ( LWS ) or high ( HWS ) juvenile body weight and have different severities of anorexia and obesity, respectively. The LWS that are exposed to stressors at hatch are refractory to neuropeptide Y ( NPY )‐induced food intake and the objective of the present study was to determine the underlying mechanisms. Chicks were exposed to a stressor (−20°C for 6 minutes and 22°C and delayed access to food for 24 hours) after hatching and the hypothalamic nuclei, including the lateral hypothalamus ( LH ), paraventricular nucleus ( PVN ), ventromedial hypothalamus ( VMH ) and arcuate nucleus ( ARC ), were collected 5 days later. In LWS but not HWS , stress exposure up‐regulated corticotrophin‐releasing factor ( CRF ), CRF receptor subtypes 1 and 2 ( CRFR 1 and CRFR 2, respectively), melanocortin receptor 4 and urocortin 3 in the PVN , as well as CRFR 2 mRNA in the VMH and ARC . In LWS , stress exposure was also associated with greater NPY and NPY receptor subtype 5 mRNA in the ARC and PVN , respectively, as well as decreased agouti‐related peptide mRNA in the ARC . In HWS , stress exposure was associated with increased CRFR 1 and decreased cocaine‐ and amphetamine‐regulated transcript in the ARC and PVN , respectively. Refractoriness of the food intake response to NPY in LWS may thus result from the over‐riding anorexigenic tone in the PVN associated with CRF signalling. Indeed, the orexigenic effect of NPY was restored when LWS were injected with a CRF receptor antagonist, astressin, before stress exposure. The results of the present study provide insights into the molecular basis of eating disorders and suggest that CRF signalling in the PVN may exacerbate the anorexic phenotype in the presence of environmental stressors.