title: The geniculohypothalamic tract in monkey and man.
abstract: The intergeniculate leaflet (IGL) of the lateral geniculate complex in rodents contains neuropeptide Y-immunoreactive (NPY-IR) neurons which project to the suprachiasmatic nucleus (SCN) of the hypothalamus. In the macaque monkey and human brain, a large portion of the pregeniculate nucleus contains NPY-IR neurons indicating that this is the primate homologue of the rodent IGL. The monkey SCN has a dense plexus of NPY-IR axons identical in location and appearance to that in rodents. As in other mammals, no NPY-IR neurons are found in the monkey SCN. In contrast, in the human SCN, the NPY-IR plexus is less dense than in the monkey and there are numerous NPY-IR neurons. This suggests that the human SCN differs in organization from that of other mammals and that the functional homologue of the mammalian geniculohypothalamic tract is local circuit NPY+ neurons within the nucleus.
authors.affiliation: Department of Neurology, State University of New York, Stony Brook 11794.
authors.forename: R Y
authors.initials: RY
authors.lastname: Moore
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D002648:Child; D005260:Female; D005829:Geniculate Bodies / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D007031:Hypothalamus / Q000166:cytology / Q000378:metabolism*; D008253:Macaca mulatta; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000378:metabolism; D009478:Neuropeptide Y / Q000378:metabolism*
chemical_list: D009478:Neuropeptide Y