Differential effects of selective lesions of cholinergic and dopaminergic neurons on serotonin-type 1 receptors in rat brain.
Serotonin (5-HT)-type1 (abbreviated as a subscript 1) receptor binding sites are discretely distributed in rat brain. High densities of [3H]5-HT1 binding sites are especially located in areas enriched with cholinergic and dopaminergic innervation, such as the substantia innominata/ventral pallidum, striatum, septal nuclei, hippocampus and substantia nigra. The possible association of [3H]5-HT1 binding sites with cholinergic or dopaminergic cell bodies and/or nerve fiber terminals was investigated by selective lesions of the substantia innominata/ventral pallidum-cortical and septohippocampal cholinergic pathways and the nigrostriatal dopaminergic projection. [3H]5-HT1 receptor binding sites are possibly located on cholinergic cell bodies in the ventral pallidum-cortical pathway since [3H]5-HT1 binding in the substantia innominata/ventral pallidal area was markedly decreased following kainic acid lesions. Fimbriaectomies markedly decreased [3H]5-HT1 binding in the hippocampus, suggesting the presence of 5-HT1 binding sites on cholinergic nerve fiber terminals in the septohippocampal pathway. Lesions of the nigrostriatal dopaminergic projection did not modify [3H]5-HT1 binding in the substantia nigra and the striatum, suggesting that 5-HT1 receptors are not closely associated with dopaminergic cell bodies and nerve terminals in this pathway. These results demonstrate differential association between 5-HT1 receptors and cholinergic and dopaminergic innervation in rat brain.
Quirion
R
R
Douglas Hospital Research Centre, Verdun, Quebec, Canada.
Richard
J
J
D000109:Acetylcholine / Q000502:physiology*; D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000502:physiology*; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004298:Dopamine / Q000502:physiology*; D006892:Hydroxydopamines / Q000633:toxicity; D007608:Kainic Acid / Q000633:toxicity; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D016627:Oxidopamine; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000502:physiology*; D012016:Reference Values; D012701:Serotonin / Q000378:metabolism; D013378:Substantia Nigra / Q000502:physiology; D014316:Tritium
D006892:Hydroxydopamines; D011985:Receptors, Serotonin; D014316:Tritium; D012701:Serotonin; D016627:Oxidopamine; D002795:Choline O-Acetyltransferase; D000109:Acetylcholine; D007608:Kainic Acid; D004298:Dopamine