In rats central chemical sympathectomy (CCS) was elicited by intracerebro-ventricular (icv) injection of two doses of 250 mug of 6-hydroxydopamine (6-OHDA) at 48 hr interval. 7 days after the last injection when full CCS is developed, 10 mug of dopamine (DA) or 5-hydroxytryptamine (5-HT) were applied icv and locomotor and exploratory activity and irritability of animals were measured. CCS reversed the depressive effect of DA on the locomotor and exploratory activity, and intensified irribability of animals. It intensified the effect of 5-HT on the exploratory activity without changing the others observed behavioral parameters. It is concluded that CCS changes reactivity of central nervous system of pharmacological effects of DA and slightly affects the central response to 5-HT.