Premium
Dopaminergic Regulation of Cannabinoid Receptor mRNA Levels in the Rat Caudate‐Plitamen: An In Situ Hybridization Study
Author(s) -
Mailleux Pierre,
Vanderhaeghen JeanJacques
Publication year - 1993
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1993.tb09807.x
Subject(s) - dopaminergic , in situ hybridization , cannabinoid receptor , cannabinoid , neuroscience , chemistry , endocrinology , medicine , messenger rna , biology , receptor , dopamine , biochemistry , gene , agonist
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 dopa‐minergic deafferentation of the striatum (characterized by a contralateral turning behavior in response to apomor‐phine, 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 D 1 receptor antagonist SCH‐23390, haloperidol, and the D 2 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.