The effect of lesions of dopaminergic and serotonergic systems on apomorphine-induced hypothermia in the rat.

Bilateral lesion of caudate nucleus or substantia nigra as well as brain transsection between telencephalon and diencephalon potentiates the body temperature fall produced by apomorphine (5 mg/kg). A lesion of nucleus accumbens septi did not prevent the hypothermia, but slightly shortened its duration. Electrolytical and chemical (with 5,6-dihydroxytryptamine) lesions of both dorsal and medial raphe nuclei alleviated the hypothermia produced by apomorphine. The lesion of medial raphe nucleus did not affect, while the lesion of dorsal raphe nucleus prevented the hypothermia induced by apomorphine or piribedil (25 mg/kg). The results show that dopaminergic neurons of telencephalon are not involved in the mechanism of induction of apomorphine hypothermia, while the neurons of dorsal raphe nucleus participate in it.