delta-9-Tetrahydrocannabinol regulates gene expression of the growth factor pleiotrophin in the forebrain.

delta-9-Tetrahydrocannabinol (THC) is a major psychoactive component of cannabis. We here studied, by quantitative in situ hybridization at the macroscopic level, the possible modulatory effects of acute THC (5 mg/kg/i.p.) on gene expression of the growth factor pleiotrophin (PTN) in the adult rat forebrain. We found, 30 min after a single injection of THC, a significant increase of PTN mRNA concentrations in the cingulate cortex (38%), fronto-parietal cortex (31%) and caudate-putamen (27%). In conclusion, this is the first report on THC regulation of growth factor gene expression in the brain.