PHENCYCLIDINE-INDUCED EXPRESSION OF C-FOS-LIKE IMMUNOREACTIVITY IN MOUSE-BRAIN REGIONS

For the purpose of studying a role of immediate early genes in psychot omimetic-induced behavioral excitation, we experimentally enhanced the locomotor activity of mice by acute administration of phencyclidine a nd examined the expression and localization of the c-fos-like and c-Ju n-like immunoreactivities;in brain regions. A single injection of phen cyclidine (5.0 mg/kg, i.p.) significantly increased not only the locom otor activity but also the expression of c-Fos-like immunoreactivity i n several brain regions, particularly in the parietal cortex, hippocam pal dentate gyrus, piriform cortex and hypothalamus. Interestingly, th e c-Fos-like immunoreactivity in the parietal cortex continued to incr ease for 1 week after the phencyclidine injection. These results indic ate that phencyclidine, even injected only once, can induce the persis tent expression of c-Fos or c-Fos-related protein(s) in the mouse brai n, and also suggest the possibility that such a c-Fos expression may u nderlie the behavioral and/or psychotomimetic effects of phencyclidine . Copyright (C) 1996 Elsevier Science Ltd.