ACTIVATION OF MULTIPLE TRANSCRIPTION FACTOR GENES BY TETRAHYDROCANNABINOL IN RAT FOREBRAIN

delta-9-TETRAHYDROCANNABINOL (THC) is a major psychoactive component o f cannabis. We have recently localized a receptor for THC in the foreb rain and found in the caudate-putamen that its gene expression is modu lated by glucocorticoids, dopamine and glutamate. Here, we report for the first time, using quantitative in situ hybridization, that acute T HC (5 mg kg(-1), i.p.) regulates the mRNA levels of multiple immediate early genes in the adult rat forebrain. Twenty minutes after a single THC injection, significant increases in concentration of the mRNAs fo r C-FOS, C-JUN and ZIF-268 were observed in the cingulate cortex (75, 45 and 37%) and for C-FOS and ZIF-268 in the fronto-parietal cortex (6 0 and 64%) and caudate-putamen (81 and 32%) while JUN-D mRNA levels we re not changed. These transcription factor genes might mediate putativ e THC modulation of neurotransmitter gene expression.