Effects of chronic cocaine exposure on corticotropin-releasing hormone binding protein in the central nucleus of the amygdala and bed nucleus of the stria terminalis

Neuroscience. 2004;123(4):1003-9. doi: 10.1016/j.neuroscience.2003.10.031.

Abstract

The neuropeptide, corticotropin-releasing hormone (CRH), has been shown to play a role in behavioral and neurobiological effects of drugs of abuse. An important modulator of CRH, the CRH binding protein (CRH-BP), has not, on the other hand, been assessed for its role in drug-associated effects. The primary objective of the present experiment was to assess whether prior, chronic exposure to cocaine modulates expression of CRH-BP, and to compare expression of the BP with that of the peptide itself. We assessed CRH-BP and CRH mRNA expression in two brain regions where CRH is known to affect responses to drugs of abuse; namely, the central nucleus of the amygdala (CeA) and bed nucleus of the stria terminalis (BNST). Male Long-Evans rats were given 14 daily injections of cocaine (30 mg/kg, i.p.) or saline. One, 3, 10, 28, or 42 days post-treatment, animals were killed and adjacent brain sections through the CeA and BNST were processed for CRH-BP and CRH by in situ hybridization. In the CeA, cocaine pre-exposure increased both CRH and CRH-BP mRNA expression 1 day post-treatment. In the dorsal BNST, cocaine pre-exposure elevated levels of CRH-BP, but not CRH, mRNA 3 days post-treatment. Taken together, the results suggest that withdrawal-induced changes in the expression of the CRH-BP, and CRH itself, are relatively short-lived and that a dysregulation in basal expression of either gene is not likely responsible for long-lasting behavioral effects noted with cocaine and other drugs of abuse.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amygdala / drug effects*
  • Amygdala / metabolism
  • Anesthetics, Local / pharmacology*
  • Animals
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cocaine / pharmacology*
  • Corticotropin-Releasing Hormone / genetics
  • Corticotropin-Releasing Hormone / metabolism
  • In Situ Hybridization / methods
  • Male
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Long-Evans
  • Septal Nuclei / drug effects*
  • Septal Nuclei / metabolism
  • Time Factors

Substances

  • Anesthetics, Local
  • Carrier Proteins
  • RNA, Messenger
  • corticotropin releasing factor-binding protein
  • Corticotropin-Releasing Hormone
  • Cocaine