Role of serotonin1A receptors on the modulation of rat spinal mono-synaptic reflexes in vitro.
The present study aimed at determining the role of the serotonin(1A) (5-HT(1A)) receptor subtype on the modulation of the mono-synaptic reflex (MSR) elicited by dorsal root stimulation and recorded from ventral roots in the hemisected spinal cord obtained from rat pups. Serotonin and 5-carboxamidotryptamine (5-CT) depressed both the MSR and the cumulative depolarisation (CD) produced by repetitive dorsal root stimulation, whereas the specific 5-HT(1A) receptor agonist (R)-(+)-8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) applied at 1 microM showed a selective depressant effect on the MSR. Superfusion of the 5-HT(1A) receptor antagonist (+)-N-tert-butyl-3(4(2-methoxyphenyl)-piperazin-1-yl)-2-phenylprpanamide ((+)WAY 100135) produced a complete blockade of 8-OH-DPAT effects. In addition (+)WAY 100135 blocked partially the effects of 5-HT and 5-CT on the MSR but not the effects of these compounds on the CD. The results are consistent with an intervention of 5-HT(1A) receptors in the modulation of non-nociceptive reflexes but do not support a prominent role for this receptor in the modulation of nociceptive reflexes.
Hedo
Gonzalo
G
Department of Physiology, Edificio de Medicina, University of Alcala, 28871 Madrid, Spain.
Ajubita
Mar
M
Lopez-Garcia
Jose A
JA
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D004558:Electric Stimulation; D009924:Organ Culture Techniques; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D044263:Receptors, Serotonin, 5-HT1; D012023:Reflex, Monosynaptic / Q000187:drug effects / Q000502:physiology*; D012701:Serotonin / Q000031:analogs & derivatives* / Q000494:pharmacology; D018490:Serotonin Agents / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013116:Spinal Cord / Q000502:physiology; D013126:Spinal Nerve Roots / Q000187:drug effects / Q000502:physiology
D010879:Piperazines; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D018490:Serotonin Agents; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; C081293:WAY 100135; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; C047087:5-carboxamidotryptamine