Dissociation of the plasticity of 5-HT1A sites and 5-HT transporter sites.
To study the early effects of neonatal 5,7-dihydroxytryptamine lesions on 5-hydroxytryptamine1A (5-HT1A) receptors, we measured regional [3H]8-OH-DPAT-labeled 5-HT1A sites in binding assays and compared them to our previous studies of [3H]paroxetine-labeled 5-HT transporter sites during the first month in the same rats. While there were significant time- and dose-dependent effects of 5,7-DHT on 5-HT transporter sites, there were no significant changes in 5-HT1A sites in cortex, hippocampus, diencephalon, brainstem, cerebellum, or spinal cord. 5,7-DHT lesions also did not alter the Ki of Gpp(NH)p at brainstem 5-HT1A sites or the Ki of 5-HT in cortex or brainstem in the presence or absence of GTP gamma S or Gpp(NH)p. There were significant regional differences between the density of 5-HT1A sites and 5-HT transporter sites. The ontogeny of brainstem 5-HT1A sites was a pattern of increases until three weeks postnatal, and 5,7-DHT lesions did not alter the ontogeny of 5-HT1A sites. These data suggest differential plasticity of 5-HT1A and 5-HT transporter binding sites during the first month after neonatal 5,7-DHT lesions.
Pranzatelli
M R
MR
Department of Neurology, George Washington University, Washington, DC 20010.
D015116:5,7-Dihydroxytryptamine / Q000633:toxicity; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D002352:Carrier Proteins / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008562:Membrane Glycoproteins / Q000187:drug effects / Q000378:metabolism*; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009928:Organ Specificity; D017374:Paroxetine / Q000378:metabolism; D051381:Rats; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D012016:Reference Values; D012701:Serotonin / Q000378:metabolism; D050486:Serotonin Plasma Membrane Transport Proteins; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D014316:Tritium
D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D011985:Receptors, Serotonin; D050486:Serotonin Plasma Membrane Transport Proteins; C493232:Slc6a4 protein, rat; D014316:Tritium; D015116:5,7-Dihydroxytryptamine; D012701:Serotonin; D017374:Paroxetine; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin