Localization of phencyclidine in the rat brain in vivo.

Male rats were injected with 3H-PCP(3 mg/kg; 1.2 mCi/rat) into the tail vein. Three minutes later, the rats were anesthetized, frozen and their heads processed for autoradiographic study. The autoradiograms illustrated diffuse distribution of 3H-PCP or its metabolites in the whole brain tissue. Increased intensity was observed in the hippocampus, corpus callosum, subicullum, thalamus, colliculus caudalis, nucleus caudatus putamen, hypothalamus, and cerebellum. These labelled regions are in accord with those which were found to change glucose metabolism, as has been observed by monitoring labelled deoxyglucose before and after PCP injection. In addition to the previously mentioned sites, radioactivity is seen in the olfactory bulb, chiasma opticus and parts of the eye (lens cortex, retina, cilliary body). The presence of radioactivity in the chiasma opticus, as well as in various parts of the eye itself, may partially explain the effect of PCP on the eye and on vision.