Sakai N, Tanaka C
Department of Pharmacology, Kobe University School of Medicine, Japan.
Brain Res. 1993 Jun 11;613(2):326-30. doi: 10.1016/0006-8993(93)90921-9.
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.
在大鼠海马齿状回切片标本中，研究了通过5-羟色胺1A（5-HT1A）受体对长时程增强（LTP）和异丙肾上腺素诱导的长时程增强（ILLP）的调节作用。5-HT1A受体的选择性激动剂8-羟基二丙胺基四氢萘（8-OH-DPAT）以剂量依赖的方式降低了这些标本中的群体峰电位（PS）幅度。5-HT1A受体拮抗剂NAN-190的应用阻断了8-OH-DPAT诱导的PS幅度降低。强直刺激（TS）期间应用8-OH-DPAT对LTP没有影响，而相反，TS期间应用NAN-90可显著增强LTP。8-OH-DPAT可逆转NAN-190诱导的LTP增强。此外，同时应用8-OH-DPAT和异丙肾上腺素可产生剂量依赖性的对异丙肾上腺素诱导的长时程增强的抑制作用。这些结果表明，5-羟色胺通过5-HT1A受体以抑制方式调节海马齿状回中的LTP。
