Z. Wang et P. Zheng, Characterization of spontaneous excitatory synaptic currents in pyramidal cells of rat prelimbic cortex, BRAIN RES, 901(1-2), 2001, pp. 303-313
Spontaneous excitatory postsynaptic currents (sEPSCs) were recorded with th
e whole-cell patch-clamp technique from 41 pyramidal cells in the layers V-
VI of the prelimbic (PL) cortex. The sEPSCs occurred randomly and the avera
ged frequency in 41 cells was 1.81 +/- 0.27 Hz. The amplitude distribution
was skewed toward larger events and could be adequately fitted by a sum of
two or three Gaussian distributions, but they could not be fitted by a sum
of Gaussian distributions with equidistant separation in all cells studied
(n = 24). Tn eight of 24 cells, after the transformation of the amplitudes
into logarithms, the skewed histogram became bell-shaped and could be adequ
ately fitted by a single Gaussian distribution, whereas in the other 16 cel
ls, after the transformation the histograms were still skewed. However, for
those latter cells. when the logarithms were transformed into difference,
the distribution of the differences in 15 of 16 cells became bell-shaped an
d could be adequately fitted by a single Gaussian distribution. The pie dis
tribution of different rise times within one cell in 1 ms bin showed that t
here were four different patterns of the rise time distribution. The amplit
ude distribution of the sEPSCs was unchanged in 10 of 22 cells after TTX, b
ut in the other 12 cells, it was changed significantly. However, for these
cells although TTX had a marked effect, it could not change the skewed dist
ribution into a single Gaussian distribution in case of both original and t
ransformed data. (C) 2001 Elsevier Science B.V. All rights reserved.