A study of the effects of clonidine on the EEG in rats treated with single and multiple doses of antidepressants.

The influence of repeated and single administrations of desipramine, amitryptiline, and mianserin on the EEG effects of clonidine has been investigated in rats implanted with chronic cortical electrodes. Clonidine induced a dose-dependent EEG synchronization in control animals. Signs of behavioral depression occurred after administration of moderate (0.1 mg/kg) and higher (0.2 mg/kg) doses of clonidine. Single doses of desipramine and amitryptiline attenuated the clonidine effect, while mianserine potentiated clonidine-induced synchronization. Antidepressants given once daily for 14 days completely (desipramine and amitryptiline) or partially (mianserin) reduced the effect of clonidine. Antidepressants alone produced only a slight effect on cortical EEG pattern.