The distribution of serotonergic 5-HT1A and non-5-HT1A recognition sites along the dorso-ventral axis of the rat hippocampus.
The distribution of serotonergic 5-HT1 binding sites along the hippocampal dorso-ventral axis was compared with [3H]5-HT uptake considered as a marker of the quantity of serotonergic nerve terminals. [3H]5-HT binding to 5-HT1A and non-5-HT1A sites, of high and low affinity for spiperone, respectively, was investigated in three parts of the hippocampus: dorsal, medial and ventral. In each hippocampal part, 5-HT1A sites constituted approximately 70% of binding sites. [3H]5-HT uptake and [3H]5-HT binding to 5-HT1A and non-5-HT1A sites were significantly higher in the ventral than in the dorsal part of the hippocampus. The dorso-ventral hippocampal gradient in [3H]5-HT binding to both 5-HT1A and non-5-HT1A sites was due to an increase of the density (Bmax) of these sites along the longitudinal hippocampal axis, but not their affinity (Kd) for [3H]5-HT. The results are discussed in the context of the previously described mismatch between the localization of serotonergic nerve terminals and serotonergic receptors in the hippocampus.
Kiedrowski
L
L
Department of Neurophysiology, Nencki Institute of Experimental Biology, Warszawa, Poland.
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism*; D007700:Kinetics; D008024:Ligands; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism; D013134:Spiperone / Q000494:pharmacology
D008024:Ligands; D009419:Nerve Tissue Proteins; D011985:Receptors, Serotonin; D012701:Serotonin; D013134:Spiperone