NEUROPEPTIDE-Y Y-1 RECEPTORS IN THE RAT FOREBRAIN - AUTORADIOGRAPHIC DEMONSTRATION OF [I-125] [LEU(31),PRO(34)]-NPY BINDING-SITES AND NEURONS EXPRESSING Y-1 RECEPTOR MESSENGER-RNA
Pj. Larsen et al., NEUROPEPTIDE-Y Y-1 RECEPTORS IN THE RAT FOREBRAIN - AUTORADIOGRAPHIC DEMONSTRATION OF [I-125] [LEU(31),PRO(34)]-NPY BINDING-SITES AND NEURONS EXPRESSING Y-1 RECEPTOR MESSENGER-RNA, Journal of receptor and signal transduction research, 15(1-4), 1995, pp. 457-472
Using the specific monoiodinated NPY analog [Leu(31),Pro(34)]-NPY we h
ave localized NPY binding sites of the Y-1 type in forebrain areas of
the rat. The resulting receptor autoradiograms were compared with the
regional distribution and cellular localization of the mRNA encoding Y
-1 receptor as demonstrated by in situ hybridization histochemistry. H
igh densities of Y-1 binding sites were present in the cerebral cortex
, the claustrum, the thalamus and the medial mammillary nucleus, while
moderate densities of Y-1 binding sites were observed in the amygdala
hippocampal complex. Lower binding densities were observed in septal n
uclei, most hypothalamic nuclei and the circumventricular organs. High
levels of Y-1 mRNA were observed in the granula cell layer of the hip
pocampal dentate gyrus, several thalamic nuclei and the hypothalamic a
rcuate nucleus, while moderate levels of Y-1 mRNA were seen in the fro
ntoparietal cortex, several thalamic nuclei, the hippocampal pyramidal
layers, the subiculum, the olfactory tubercle, the claustrum and a nu
mber of hypothalamic nuclei. Using the hypothalamic arcuate nucleus as
an example, the distribution of immunoreactive NPY, Y-1 mRNA and Y-1
binding sites was compared, and possible implications of Y-1 mediated
actions within this nucleus are discussed. The present study further e
nlightens the anatomical distribution of NPY binding sites of the Y-1
type within the central nervous system of the rat, and extends the und
erstanding of central actions of NPY mediated via this type of recepto
r.