Region-specific down-regulation of Crhr1 gene expression in alcohol-preferring msP rats following ad lib access to alcohol

Addict Biol. 2007 Mar;12(1):30-4. doi: 10.1111/j.1369-1600.2007.00050.x.

Abstract

Corticotropin-releasing hormone 1 receptors (CRH-R1) mediate increased behavioral sensitivity to stress and excessive alcohol self-administration following a history of dependence. It was recently demonstrated that the genetically selected alcohol-preferring msP rat line replicates many characteristics of the post-dependent state, due to an innate up-regulation of the Crhr1 transcript in several limbic areas related to alcohol drinking motivation. Here, we examined whether voluntary alcohol consumption might be able to down-regulate Crhr1 transcript levels in msP rats in brain areas where elevated expression previously has been shown. Within central and medial amygdala (CeA, MeA), as well as the Nc. Accumbens, 2 weeks'ad lib access to alcohol led to a highly significant down-regulation of the Crhr1 transcript. Alcohol-induced Crhr1 down-regulation was not seen in cingulate cortex. These data support that recruitment of CRH-R1 signaling within components of the extended amygdala drives excessive alcohol intake, and that alcohol is voluntarily consumed in part for its ability to reduce CRH-R1 activity in this region.

MeSH terms

  • Alcoholism / genetics*
  • Amygdala / metabolism*
  • Animals
  • Down-Regulation / genetics
  • Gyrus Cinguli / metabolism
  • In Situ Hybridization
  • Male
  • Nucleus Accumbens / metabolism*
  • Rats
  • Rats, Inbred Strains
  • Receptors, Corticotropin-Releasing Hormone / genetics*

Substances

  • Receptors, Corticotropin-Releasing Hormone
  • CRF receptor type 1