[125I]galanin binding sites in the rat frontal lobe are guanine nucleotide-sensitive and display a low regional index of occupancy.
As the neuropeptide galanin is possibly involved in spatial learning, we investigated both the precise location and the binding features of the receptors within the rat frontal cortex using quantitative autoradiography. Galanin receptors predominated in layers I and V of medial and lateral frontal cortex with a low regional index of occupancy by endogenous galanin. These receptors might be of functional relevance since the guanylnucleotide Gpp(NH)p inhibited [125I]galanin specific binding in each labeled region in the frontal lobe. Nevertheless, the striking areal difference of expression of this effect within the medial frontal cortex suggests that [125I]galanin binding sites might be coupled to one or more types of G-proteins related to the functionally distinct cortical subareas.
Lagny-Pourmir
I
I
Laboratoire de Neurobiologie et Neuropharmacolgie du développement, CNRS URA 1121, Orsay, France.
Crépel
F
F
D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive / Q000187:drug effects; D005625:Frontal Lobe / Q000187:drug effects / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism; D006150:Guanine Nucleotides / Q000494:pharmacology*; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007457:Iodine Radioisotopes; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D044088:Receptors, Galanin; D011964:Receptors, Gastrointestinal Hormone / Q000187:drug effects / Q000378:metabolism*
D006150:Guanine Nucleotides; D007457:Iodine Radioisotopes; D044088:Receptors, Galanin; D011964:Receptors, Gastrointestinal Hormone; D006165:Guanylyl Imidodiphosphate; D019204:GTP-Binding Proteins