The Journal of Neuroscience, June 28, 2006, ():
Ongoing Epileptiform Activity in the Post-Ischemic Hippocampus Is Associated with a Permanent Shift of the Excitatory–Inhibitory Synaptic Balance in CA3 Pyramidal Neurons
J. Neurosci. Epsztein et al.
26: 7082
Supplemental data
Files in this Data Supplement:
- supplemental material
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Supplementary Figure 1. CA1 pyramidal cell loss and preservation of CA3 pyramidal cells in the hippocampus from post-ischemic rats
Cresyl violet staining of a coronal section of the rat hippocampal formation 3 months after ischemia (upper photomicrograph, x 4). Note that CA1 pyramidal layer disappeared (see lower photomicrograph, x 40), whereas the CA3 region (see lower photomicrograph, x 40) and the dentate gyrus are preserved. O, P and R: stratum oriens, pyramidal and radiatum of CA1 and CA3. DG: dentate gyrus.
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Supplementary Figure 2. Ripple events in the hippocampus from control and post-ischemic rat
A, In vitro extracellular recording in the CA3 pyramidal layer in hippocampal slices from a control rat (top) reveal the presence of spontaneous high-frequency oscillations of short duration and small amplitude (ripple, asterisk, enlarged in a and b). In hippocampal slices from a post-ischemic rat (bottom), ripple events of similar duration and amplitude were also recorded (asterisk, enlarged in c) in addition to spontaneous IED-like activities (arrow, enlarged in d). Note the difference in amplitude and duration between ripple and IED-like activities in hippocampal slices from post-ischemic rats. B, Power spectrum of all in vitro recorded ripple events in hippocampal slices from control (left, n= 176 in 7 slices) and post-ischemic rats (right, n=107 in 4 slices) reveal a major component between 100 and 200 Hz (mean 144 Hz for control and 171 Hz for post-ischemic rats). Note the difference in the mean component and the power between ripple and IED-like activities in hippocampal slices from post-ischemic rats (for comparison see also Fig. 1).
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Supplementary Figure 3. EPSCKAs can be isolated from mEPSCs based on their pharmacological and kinetic profile in CA3 pyramidal cells from post-ischemic rats
A, Miniature EPSCs recordings in the presence of TTX (1 然), bicuculline (10 然), and D-APV (50 然) from a representative CA3 pyramidal cell from a post-ischemic rat, show that mEPSCKAs (closed purple circle) can be isolated pharmacologically when GYKI 52466 (100 然) is added to the saline and blocked by CNQX (50 然); Vh: -70 mV. Note that in control conditions in the post-ischemic CA3 pyramidal cell, three types of mEPSCs can be distinguished based on the time course of their decay: fast (closed black circle), slow (closed green circle), and mixed EPSCs with a double decaying phase (closed red circle). B, Scatter plots of the rise time constant (top) or amplitude (bottom) versus the decay time constant were calculated for mEPSCs (n=84) recorded in a CA3 pyramidal cell from a post-ischemic rat in the absence (left) or in the presence of GYKI (100 然, right). Note that the fast (closed black circle) and the slow events (closed green circle) are clustered in separate areas of the graph. In the presence of GYKI, only events with a slow time course and a small amplitude (closed purple circle) remain. C, Superimpositions of the digitally averaged traces of fast (black), mixed (red), and slow (green) mEPSCs and GYKI-resistant mEPSCs (purple). Note that slow events, the second component of mixed events, and GYKI-resistant events have a similar time course. D, Bar graph of averaged values of rise times (left) and decay times (right) show that, in CA3 pyramidal cells from post-ischemic rats, the time course of slow events (slow, n=9 cells) and GYKI resistant events (n=5 cells) are not significantly different (p > 0.05). In contrast, the time course of slow events and GYKI resistant events are significantly different from that of fast events ( n=9 cells; * p<0.05).
