MENINGOCORTICAL LESION INCREASES EXPRESSION OF THE CHOLECYSTOKININ GENE IN RAT CEREBRAL-CORTEX - EVIDENCE FOR THE INVOLVEMENT OF PLATELET-ACTIVATING-FACTOR (PAF)

In rat neocortex, interneurons express the gene encoding cholecystokin in. After an injury to the meninges and the underlying cortex the leve ls of cholecystokinin mRNA are transiently enhanced in the ipsilateral hemisphere. In the present study, we have investigated, whether plate let-activating factor plays a role in this phenomenon. Two antagonists of platelet-activating receptors, i.e. WEB 2086 (1.5 mg/kg) and broti zolam (10 mg/kg), were used. When injected 30 min prior to the injury of the parietal cortex, both agents reduced the rise in the concentrat ion of cholecystokinin mRNA in frontal cortex by approximately 60%. Th ey had no significant effect when given 30 min after the injury. Our f inding that antagonists of platelet-activating factor receptors dimini sh the injury-induced change in the activity of cholecystokinin-intern eurons opens the possibility that these agents may also affect other p athophysiological apects of brain trauma.