Protein kinase C epsilon mediation of CRF- and ethanol-induced GABA release in central amygdala

Proc Natl Acad Sci U S A. 2008 Jun 17;105(24):8410-5. doi: 10.1073/pnas.0802302105. Epub 2008 Jun 9.

Abstract

In the central amygdala (CeA), ethanol acts via corticotrophin-releasing factor (CRF) type 1 receptors to enhance GABA release. Amygdala CRF mediates anxiety associated with stress and drug dependence, and it regulates ethanol intake. Because mutant mice that lack PKCepsilon exhibit reduced anxiety-like behavior and alcohol consumption, we investigated whether PKCepsilon lies downstream of CRF(1) receptors in the CeA. Compared with PKCepsilon(+/+) CeA neurons, PKCepsilon(-/-) neurons showed increased GABAergic tone due to enhanced GABA release. CRF and ethanol stimulated GABA release in the PKCepsilon(+/+) CeA, but not in the PKCepsilon(-/-) CeA. A PKCepsilon-specific inhibitor blocked both CRF- and ethanol-induced GABA release in the PKCepsilon(+/+) CeA, confirming findings in the PKCepsilon(-/-) CeA. These results identify a PKCepsilon signaling pathway in the CeA that is activated by CRF(1) receptor stimulation, mediates GABA release at nerve terminals, and regulates anxiety and alcohol consumption.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Drinking / genetics
  • Alcohol Drinking / metabolism*
  • Amygdala / drug effects*
  • Amygdala / enzymology
  • Animals
  • Anxiety / enzymology*
  • Anxiety / genetics
  • CRF Receptor, Type 1
  • Corticotropin-Releasing Hormone / metabolism*
  • Corticotropin-Releasing Hormone / pharmacology
  • Ethanol / pharmacology*
  • Male
  • Mice
  • Mice, Mutant Strains
  • Neurons / drug effects
  • Neurons / metabolism
  • Neurons / physiology
  • Protein Kinase C-epsilon / genetics
  • Protein Kinase C-epsilon / physiology*
  • Receptors, Corticotropin-Releasing Hormone / agonists
  • Receptors, Corticotropin-Releasing Hormone / metabolism
  • Synaptic Transmission / drug effects
  • gamma-Aminobutyric Acid / metabolism*

Substances

  • Receptors, Corticotropin-Releasing Hormone
  • Ethanol
  • gamma-Aminobutyric Acid
  • CRF Receptor, Type 1
  • Corticotropin-Releasing Hormone
  • Protein Kinase C-epsilon