title: Origin of the neuropeptide Y innervation of the rat retrohippocampal region.
abstract: Using the method of retrograde tracing of Fast Blue in combination with immunohistochemistry, the origins of the retrohippocampal neuropeptide Y (NPY) innervation was studied in the rat brain. The findings suggest that two NPY-immunoreactive (NPY-i) afferent systems, one intrinsic and the other of extrinsic origin give rise to the massive NPY innervation of the retrohippocampal region, including the entorhinal area (EA). The intrinsic projections originate from multipolar and fusiform cells situated primarily in layers IV through VI of the medial and lateral EA, as well as from a small number of NPY-i basket cells situated in layer II. Other NPY-i afferents originate from cortical neurons with long association projections located in the deep layers of the perirhinal area and in the piriform cortex, as well as from cells situated throughout the rostrocaudal extent of the endopiriform nucleus, in the lateral nucleus of amygdala and in the nucleus locus coeruleus.
mesh_terms: D000578:Amidines; D000818:Animals; D001931:Brain Mapping; D005455:Fluorescent Antibody Technique; D006624:Hippocampus / Q000032:analysis / Q000033:anatomy & histology*; D008297:Male; D009419:Nerve Tissue Proteins / Q000032:analysis*; D009478:Neuropeptide Y; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000578:Amidines; D009419:Nerve Tissue Proteins; D009478:Neuropeptide Y; C031455:diamidino compound 253-50