BENZODIAZEPINES INCREASE PREPROCHOLECYSTOKININ MESSENGER-RNA LEVELS IN RAT-BRAIN

Using in situ hybirdisation, the effects of acute and chronic diazepam administration and diazepam withdrawal on preprocholecystokinin (CCK) mRNA levels in discrete regions of rat brain were determined. In cere bral cortex and a subpopulation of hippocampal neurones, CCK mRNA leve ls were increased after a single injection of diazepam and 24 h after withdrawal from chronic diazepam treatment, but not after chronic diaz epam treatment. These results show that, in some neuronal groups, CCK mRNA expression is regulated by benzodiazepines, although there is no clear link between CCK mRNA levels and anxiety state.