Dopaminergic regulation of cannabinoid receptor mRNA levels in the rat caudate-putamen: an in situ hybridization study

J Neurochem. 1993 Nov;61(5):1705-12. doi: 10.1111/j.1471-4159.1993.tb09807.x.

Abstract

By quantitative in situ hybridization, we examined in vivo in the rat caudate-putamen the effects on levels of cannabinoid receptor mRNA of an interruption of dopamine neurotransmission for up to 1 month, by either 6-hydroxydopamine lesioning of the medial forebrain bundle or dopamine receptor blockade. We found, in a first set of experiments, that unilateral 6-hydroxydopamine dopaminergic deafferentation of the striatum (characterized by a contralateral turning behavior in response to apomorphine, the almost complete disappearance of the tyrosine hydroxylase hybridization signal in the substantia nigra, and an increase of preproenkephalin A mRNA level in the striatum) was associated with significantly increased (45%) cannabinoid receptor mRNA levels in the homolateral caudate-putamen. In a second set of experiments, treatments with the dopamine D1 receptor antagonist SCH-23390, haloperidol, and the D2 receptor antagonist sulpiride induced significantly higher cannabinoid receptor mRNA levels (respectively, 67, 34, and 27%) in the caudate-putamen. These observations suggest for the first time that, in vivo, cannabinoid receptor gene expression in the caudate-putamen is under the negative control of dopamine receptor-mediated events.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autoradiography
  • Caudate Nucleus / metabolism*
  • Corpus Striatum / drug effects
  • Corpus Striatum / pathology
  • Dopamine / metabolism*
  • Gene Expression / drug effects
  • In Situ Hybridization
  • Male
  • Mesencephalon / metabolism
  • Oxidopamine / toxicity
  • Putamen / metabolism*
  • RNA, Messenger / metabolism*
  • Rats
  • Rats, Wistar
  • Receptors, Cannabinoid
  • Receptors, Drug / biosynthesis*
  • Receptors, Drug / drug effects
  • Sulfur Radioisotopes
  • Tyrosine 3-Monooxygenase / analysis

Substances

  • RNA, Messenger
  • Receptors, Cannabinoid
  • Receptors, Drug
  • Sulfur Radioisotopes
  • Oxidopamine
  • Tyrosine 3-Monooxygenase
  • Dopamine