title: Dopaminergic activation of reticulata neurones in the substantia nigra.
abstract: Dendritic release of dopamine (DA) in substantia nigra (SN) is well established in various experimental situations. Morphological substrates for DA storage exist in dendrites, as do dendro-dendritic and dendro-axonic contacts. DA receptors in SN are located on both cells and striato-nigral terminals. DA is thought to regulate the activity of neighbouring dopaminergic neurones through its dendritic release by a local feedback mechanism. However, dendrites of DA neurones also ramify close to the neuropil of non-dopaminergic reticulata neurones in SN. The question has arisen whether dendritically release DA might also influence these neurones which, to a large extent, project to ventromedial thalamus (VM) and superior colliculus. A necessary condition would be that they are sensitive to DA. In the experiments reported here this was found to be the case--a considerable proportion of nigrothalamic neurones were activated by iontophoretically applied DA. This contrasts with its known depressant effect on pars compacta DA neurones which we confirmed.
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D004298:Dopamine / Q000494:pharmacology*; D005260:Female; D008297:Male; D009434:Neural Pathways / Q000187:drug effects; D051381:Rats; D013378:Substantia Nigra / Q000166:cytology / Q000187:drug effects*; D013788:Thalamus / Q000166:cytology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
chemical_list: D005680:gamma-Aminobutyric Acid; D004298:Dopamine