High-voltage-activated Ca2+ currents and the excitability of pyramidal neurons in the hippocampal CA3 subfield in rats depend on corticosterone and time of day

Citation
Mhp. Kole et al., High-voltage-activated Ca2+ currents and the excitability of pyramidal neurons in the hippocampal CA3 subfield in rats depend on corticosterone and time of day, NEUROSCI L, 307(1), 2001, pp. 53-56
Citations number
19
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences & Behavoir
Journal title
NEUROSCIENCE LETTERS
ISSN journal
0304-3940 → ACNP
Volume
307
Issue
1
Year of publication
2001
Pages
53 - 56
Database
ISI
SICI code
0304-3940(20010706)307:1<53:HCCATE>2.0.ZU;2-8
Abstract
This study tested the time-of-day dependence of the intrinsic postsynaptic properties of hippocampal CA3 pyramidal neurons. High-voltage-activated Ca2 + currents and the Ca2+- and voltage-dependent afterhyperpolarizations were examined in slices of rat brains obtained at four distinct time periods. J ust after onset of the dark phase, the steady-state amplitude of the Ca2+ c urrent (-1.24 +/- 0.11 nA) was significantly greater (P < 0.03) than that o f the light phase (-0.84 +/- 0.06 nA). Over the entire time range, the ampl itude of the Ca2+ current correlated with plasma corticosterone levels in a U-shaped function. Furthermore, depolarization-induced excitability during the dark phase exhibited an increased spike after depolarization (3.1 +/- 0.1 mV) and a slower adaptation of the firing frequency (146 +/- 18%). Thes e findings point to a dynamic time-of-day dependence of the CA3 neuronal pr operties and postsynaptic Ca2+ currents. (C) 2001 Published by Elsevier Sci ence Ireland Ltd.