Serotoninergic projections from the raphe nuclei to the preoptic area in sheep as revealed by immunohistochemistry and retrograde labeling.
A retrograde tracer, fluorogold, was injected into the sheep preoptic area in order to demonstrate the origin of the serotoninergic fibers observed in this area. Within the raphe nuclei, retrogradely fluorogold-labeled neurons were observed mainly in the median raphe nucleus (B8), groups B6/B5, and in the area lateral to the nucleus interpeduncularis (group S4), but not in the dorsal raphe nucleus. About 50% of these fluorogold-containing neurons were immunostained with a specific antiserum raised against serotonin. Double-labeled neurons (serotonin-immunoreactive and fluorogold containing neurons) represented less than 20% of the whole number of serotoninergic neurons. We concluded that a few serotoninergic neurons in the median raphe nucleus and in groups B5/B6 and S4 project to the preoptic area. Moreover, these nuclei contained non-serotoninergic neurons which project to the same area. These results give new information on the serotoninergic innervation of the preoptic area in the sheep.
Tillet
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Laboratoire de Neuroendocrinologie Sexuelle, INRA, Nouzilly, France.
D000818:Animals; D003594:Cytoplasmic Granules / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D005456:Fluorescent Dyes; D007150:Immunohistochemistry; D009434:Neural Pathways / Q000166:cytology / Q000502:physiology; D011301:Preoptic Area / Q000166:cytology* / Q000502:physiology; D011903:Raphe Nuclei / Q000166:cytology* / Q000502:physiology; D012701:Serotonin / Q000502:physiology*; D012756:Sheep; D013266:Stilbamidines
C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; D005456:Fluorescent Dyes; D013266:Stilbamidines; D012701:Serotonin