Dissection of corticotropin-releasing factor system involvement in locomotor sensitivity to methamphetamine

Genes Brain Behav. 2011 Feb;10(1):78-89. doi: 10.1111/j.1601-183X.2010.00641.x. Epub 2010 Sep 30.


Sensitivity to the euphoric and locomotor-activating effects of drugs of abuse may contribute to risk for excessive use and addiction. Repeated administration of psychostimulants such as methamphetamine (MA) can result in neuroadaptive consequences that manifest behaviorally as a progressive escalation of locomotor activation, termed psychomotor sensitization. The present studies addressed the involvement of specific components of the corticotropin-releasing factor (CRF) system in locomotor activation and psychomotor sensitization induced by MA (1, 2 mg/kg) by utilizing pharmacological approaches, as well as a series of genetic knockout (KO) mice, each deficient for a single component of the CRF system: CRF-R1, CRF-R2, CRF, or the CRF-related peptide Urocortin 1 (Ucn1). CRF-R1 KO mice did not differ from wild-type mice in sensitization to MA, and pharmacological blockade of CRF-R1 with CP-154,526 (15, 30 mg/kg) in DBA/2J mice did not selectively attenuate either the acquisition or expression of MA-induced sensitization. Deletion of either of the endogenous ligands of CRF-R1 (CRF, Ucn1) either enhanced or had no effect on MA-induced sensitization, providing further evidence against a role for CRF-R1 signaling. Interestingly, deletion of CRF-R2 attenuated MA-induced locomotor activation, elucidating a novel contribution of the CRF system to MA sensitivity, and suggesting the participation of the endogenous urocortin peptides Ucn2 and Ucn3. Immunohistochemistry for Fos was used to visualize neural activation underlying CRF-R2-dependent sensitivity to MA, identifying the basolateral and central nuclei of the amygdala as neural substrates involved in this response. Our results support further examination of CRF-R2 involvement in neural processes associated with MA addiction.

Publication types

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

MeSH terms

  • Animals
  • Central Nervous System Stimulants / pharmacology*
  • Corticotropin-Releasing Hormone / genetics
  • Corticotropin-Releasing Hormone / physiology*
  • Female
  • Gene Deletion
  • Immunohistochemistry
  • Male
  • Methamphetamine / pharmacology*
  • Mice
  • Mice, Inbred DBA
  • Mice, Knockout
  • Motor Activity / drug effects*
  • Motor Activity / physiology*
  • Mutation / genetics
  • Mutation / physiology
  • Proto-Oncogene Proteins c-fos / metabolism
  • Receptors, Corticotropin-Releasing Hormone / antagonists & inhibitors
  • Receptors, Corticotropin-Releasing Hormone / genetics
  • Urocortins / genetics


  • CRF receptor type 2
  • Central Nervous System Stimulants
  • Proto-Oncogene Proteins c-fos
  • Receptors, Corticotropin-Releasing Hormone
  • Urocortins
  • Methamphetamine
  • CRF receptor type 1
  • Corticotropin-Releasing Hormone