OPIOIDERGIC AND DOPAMINERGIC GENE-EXPRESSION IN THE CAUDATE-PUTAMEN AND ACCUMBENS OF THE MUTANT MOUSE, TOTTERING (TG TG)/

Expression of preproenkephalin, dynorphin and D-2 dopamine receptor mR NAs was examined in selected regions of the forebrain of homozygous an d heterozygous tottering mice, using in situ hybridization histochemis try. Homozygous tottering mice carry an autosomal recessive mutation c ausing them to exhibit petit mal-like epilepsy. Preproenkephalin mRNA levels were significantly higher in the lateral caudate and the core o f the nucleus accumbens of homozygous tottering mice compared to wild- type controls. No differences were observed in the expression of dynor phin and D-2 receptor mRNA distribution in brain regions examined in t he mutant mice as compared to wild-type controls. (C) 1997 Elsevier Sc ience B.V.