Autoradiographic mapping of spirodecanone binding-sites in the hippocampal region of the rat. Evidence for a localization on intrinsic neurons.
The method of in vitro receptor autoradiography was used to map the distribution of spirodecanone binding-sites in the rat hippocampal region. Incubations of horizontal sections through the hippocampus with [3H]spiperone (1 nM) resulted in dense labeling restricted to the pyramid cell layer in CA1, the parasubiculum and layers I and II of the entorhinal area (EA), while the other hippocampal subfields contained moderate to low binding. ADTN, serotonin, ketanserin and mianserin (1-100 microM) all failed to displace the [3H]spiperone in the layers of densest binding, while displacement of the [3H]spiperone binding occurred with high concentrations of spiperone (1 microM) and haloperidol (100 microM). Intra-entorhinal injections of the neurotoxin ibotenic acid prevented [3H]spiperone binding to layers I and II of the EA, while transections of septal and commissural afferents or the degeneration of serotonin and noradrenaline terminals appeared not to reduce the [3H]spiperone binding in any part of the hippocampal region. These findings suggest that spirodecanone binding-sites are located on intrinsic neurons in restricted laminae of the hippocampal region.
D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive; D001931:Brain Mapping; D002090:Butyrophenones / Q000378:metabolism*; D006220:Haloperidol / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism*; D007650:Ketanserin; D008297:Male; D008803:Mianserin / Q000378:metabolism; D010880:Piperidines / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011954:Receptors, Dopamine; D012701:Serotonin / Q000378:metabolism; D013134:Spiperone / Q000378:metabolism*; D013764:Tetrahydronaphthalenes / Q000378:metabolism
D002090:Butyrophenones; D010880:Piperidines; D011956:Receptors, Cell Surface; D011954:Receptors, Dopamine; D013764:Tetrahydronaphthalenes; C038349:spirodecanone receptor; D008803:Mianserin; D012701:Serotonin; D013134:Spiperone; C011639:ADTN; D007650:Ketanserin; D006220:Haloperidol