Inhibitory modulation of long-term potentiation via the 5-HT1A receptor in slices of the rat hippocampal dentate gyrus.
Modulation of long-term potentiation (LTP) and isoproterenol-induced long-lasting potentiation (ILLP) via the 5-HT1A receptor was examined in slice preparations of the rat hippocampal dentate gyrus. 8-OH-DPAT, a selective agonist of the 5-HT1A receptor, decreased population spike (PS) amplitude in these preparations, in a dose-dependent manner. Application of NAN-190, an antagonist of the 5-HT1A receptor, blocked the 8-OH-DPAT-induced decrease in PS amplitude. LTP was not affected by application of 8-OH-DPAT during tetanic stimulation (TS), while in contrast, application of NAN-190 during TS significantly augmented LTP. The NAN-190-induced enhancement of LTP was reversed by 8-OH-DPAT. In addition, a dose-dependent inhibition of isoproterenol-induced long-lasting potentiation was produced by simultaneous application of 8-OH-DPAT and isoproterenol. These results suggests that 5-HT modulates LTP in the hippocampal dentate gyrus via the 5-HT1A receptor, in an inhibitory fashion.
Sakai
N
N
Department of Pharmacology, Kobe University School of Medicine, Japan.
Tanaka
C
C
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D017774:Long-Term Potentiation / Q000187:drug effects*; D008297:Male; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D013997:Time Factors
D010879:Piperazines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; C058895:1-(2-methoxyphenyl)-4-(4-(2-phthalimido)butyl)piperazine; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D007545:Isoproterenol