In:
Journal of Neurochemistry, Wiley, Vol. 103, No. 6 ( 2007-12), p. 2342-2353
Abstract:
Serotoninergic modulation of GABAergic mIPSCs was investigated in immature (postnatal 12–16‐days old) rat CA3 pyramidal neurons using a conventional whole‐cell patch clamp technique. Serotonin or 5‐hydroxytryptamine (5‐HT) (10 μmol/L) transiently and explosively increased mIPSC frequency with a small increase in the current amplitude. However, 5‐HT did not affect the GABA‐induced postsynaptic currents, indicating that 5‐HT acts presynaptically to facilitate the probability of spontaneous GABA release. The 5‐HT action on GABAergic mIPSC frequency was completely blocked by 100 nmol/L MDL72222, a selective 5‐HT 3 receptor antagonist, and mimicked by mCPBG, a selective 5‐HT 3 receptor agonist. The 5‐HT action on GABAergic mIPSC frequency was completely occluded either in the presence of 200 μmol/L Cd 2+ or in the Na + ‐free external solution, suggesting that the 5‐HT 3 receptor‐mediated facilitation of mIPSC frequency requires a Ca 2+ influx passing through voltage‐dependent Ca 2+ channels from the extracellular space, and that presynaptic 5‐HT 3 receptors are less permeable to Ca 2+ . The 5‐HT action on mIPSC frequency in the absence or presence of extracellular Na + gradually increased with postnatal development. Such a developmental change in the 5‐HT 3 receptor‐mediated facilitation of GABAergic transmission would play important roles in the regulation of excitability as well as development in CA3 pyramidal neurons.
Type of Medium:
Online Resource
ISSN:
0022-3042
,
1471-4159
DOI:
10.1111/jnc.2007.103.issue-6
DOI:
10.1111/j.1471-4159.2007.04945.x
Language:
English
Publisher:
Wiley
Publication Date:
2007
detail.hit.zdb_id:
2020528-4
SSG:
12
