Distribution of histaminergic, muscarinic and serotonergic binding sites in cat spinal cord with emphasis on the region surrounding the central canal.
[3H]Quinuclidinyl benzilate (QNB), [3H]lysergic acid diethylamide (LSD) and [3H]pyrilamine were used with radiohistochemistry to determine the distribution of muscarinic, serotonergic and histaminergic binding sites, respectively, in cat spinal cord. Each ligand displayed a unique pattern of binding sites in the superficial laminae of the dorsal horn [3H]Pyrilamine binding sites were localized most superficially, while [3H]LSD binding sites were densest in the region of the laminae II/III border. The distribution of [3H]QNB binding sites partially overlapped those of LSD and pyrilamine. In the region surrounding the central canal, pyrilamine binding sites were concentrated within a zone 100 microns lateral to the canal while [3H]QNB and [3H]LSD binding sites were localized outside of this zone. The distribution of binding sites in the region surrounding the central canal may provide an important neurochemical correlate for lamina X in the cat as defined by Rexed.
D000818:Animals; D001665:Binding Sites; D002415:Cats; D006651:Histocytochemistry; D066298:In Vitro Techniques; D008024:Ligands; D008238:Lysergic Acid Diethylamide / Q000378:metabolism; D011738:Pyrilamine / Q000378:metabolism; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D011854:Radiochemistry; D011968:Receptors, Histamine / Q000378:metabolism*; D011969:Receptors, Histamine H1 / Q000378:metabolism*; D011976:Receptors, Muscarinic / Q000378:metabolism*; D011985:Receptors, Serotonin / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism*
D008024:Ligands; D011968:Receptors, Histamine; D011969:Receptors, Histamine H1; D011976:Receptors, Muscarinic; D011985:Receptors, Serotonin; D011813:Quinuclidinyl Benzilate; D008238:Lysergic Acid Diethylamide; D011738:Pyrilamine