title: Differential serotonergic innervation of individual hypothalamic nuclei and other forebrain regions by the dorsal and median midbrain raphe nuclei.
abstract: Lesions in the midbrain median but not in the dorsal raphe nucleus significantly decreased the serotonin (5-HT) content of the hippocampus (61%), medial preoptic area (49%), suprachiasmatic nucleus (70%) and anterior hypothalamic area (60%). Electrolytic lesions restricted to either the median or dorsal raphe nucleus produced significant reductions in the 5-HT concentration of the caudate-putamen, anterolateral hypothalamic area (45%) and arcuate nucleus (48--58%). The fall in caudate-putamen 5-HT level was significantly greater after the dorsal (66%) than after the median (24%) raphe lesion. Neither lesion significantly affected the 5-HT content of the posterolateral hypothalamic area, the ventromedial hypothalamic nucleus or the dorsomedial hypothalamic nucleus. Thus, like their differential projections to the caudate-putamen and hippocampus, the mesencephalic dorsal and median raphe nuclei appear to innervate different preoptico-hypothalamic nuclei and areas. Whereas the median raphe nucleus seems to be the primary source of 5-HT fibers to the suprachiasmatic nucleus, anterior hypothalamic area and medial preoptic area, the 5-HT inputs to the anterolateral hypothalamic area and arcuate nucleus appear to derive from both the dorsal and median raphe nuclei.
mesh_terms: D000818:Animals; D001931:Brain Mapping; D001933:Brain Stem / Q000033:anatomy & histology*; D002421:Caudate Nucleus / Q000033:anatomy & histology* / Q000502:physiology; D006624:Hippocampus / Q000033:anatomy & histology* / Q000502:physiology; D007031:Hypothalamus / Q000033:anatomy & histology* / Q000502:physiology; D008297:Male; D008636:Mesencephalon / Q000033:anatomy & histology*; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D011301:Preoptic Area / Q000033:anatomy & histology; D011699:Putamen / Q000033:anatomy & histology* / Q000502:physiology; D011903:Raphe Nuclei / Q000033:anatomy & histology* / Q000502:physiology; D051381:Rats; D012701:Serotonin / Q000378:metabolism*
chemical_list: D012701:Serotonin