title: The importance of 5-hydroxytryptamine for the induction of harmine tremor and its antagonism by dopaminergic agonists assessed by lesions of the midbrain raphe nuclei.
abstract: The brain lesion technique was used to destroy the ascending 5-hydroxytryptamine (5-HT) system at its cell bodies in the dorsal and medial raphe nuclei in order to assess the importance of 5-HT for the induction of harmine tremor and its antagonism by the dopaminergic agonists, L-DOPA, apomorphine and d-amphetamine. Lesions of the medial or dorsal raphe nucleus reduced the intensity of harmine tremor. The remaining tremor was generally resistant to further reduction by the dopaminergic agonists. 5-hydroxytryptophan was shown to enhance tremor: this effect was reduced both by the raphe lesions and by treatment with L-DOPA. The data are discussed in terms of the possible relationship between 5-HT and dopamine.
mesh_terms: D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D003913:Dextroamphetamine / Q000494:pharmacology; D006247:Harmine / Q000494:pharmacology*; D007980:Levodopa / Q000494:pharmacology; D008297:Male; D008636:Mesencephalon / Q000502:physiology*; D009424:Nervous System Physiological Phenomena; D009434:Neural Pathways / Q000502:physiology*; D051381:Rats; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists; D014202:Tremor / Q000139:chemically induced*
chemical_list: D000470:Alkaloids; D012702:Serotonin Antagonists; D012701:Serotonin; D007980:Levodopa; D006247:Harmine; D001058:Apomorphine; D003913:Dextroamphetamine