Differential expression of c-Fos following administration of two tremorgenic agents: harmaline and oxotremorine

The regional distribution of c-Fos expression in the brain after the admini stration of two tremorgenic agents was studied. In both the harmaline- and oxotremorin-treated rats, c-fos-positive neurons were extensively distribut ed in the basal ganglia nuclei and the cerebellum. Additionally, in the har maline-treated rats, numerous c-fos-positive neurons were also distributed throughout the inferior olivary nucleus. In the oxotremorine-treated rats, while the inferior olive was not involved, c-Fos was strongly expressed in the neurons of the reticular thalamic nucleus, possibly due to the muscarin ic effects of oxotremorine. The present study revealed that the inferior ol ive is selectively activated in the harmaline-administered animals and that the basal ganglia are involved in both harmaline- and oxotremorine-induced tremors. NeuroReport 11:2385-2390 (C) 2000 Lippincott Williams & Wilkins.