Nicotine-induced Fos-like immunoreactivity in rat sympathetic ganglia and adrenal medulla

Abstract

The expression of c-fos proteins (Fos) in principal sympathetic neurons and adrenal chromaffin cells was studied immunocytochemically after a single s.c. injection of nicotine (2 mg/kg). One and 2 h after injection most of the adrenal chromaffin cells showed nuclear Fos-like immunoreactivity (Fos-IR). In the superior cervical ganglion more than 80 % of the neuronal nuclei were Fos-IR 2–5 h after nicotine administration, whereas only 50–60 % of the neurons in the hypogastric ganglion were immunoreactive at these time points. The results suggest that nicotinic receptor mediates signal transduction, which induces c-fos expression both in sympathetic neurons and in adrenal chromaffin cells in vivo.