Differential modulation of short-term plasticity at hippocampal mossy fiber and Schaffer collateral synapses by mitochondrial Ca2+
Fig 5
Inhibition of mitochondrial Ca2+ release selectively reduces synaptic facilitation at MF synapses.
(A) Representative EPSCs recorded before and after treatment of CGP37157 (20 μM) on frequency facilitation elicited by 20 Hz stimulus train at MF synapses. Scale bar: 100 ms, 100 pA. (B) Inhibition of mitochondrial Ca2+ release by CGP37157 significantly reduces synaptic facilitation at MF synapses (F1, 16 = 10.23, p = 0.0056; two-way ANOVA). (C) Summary graph of the mean magnitude of the 10th stimulus train of frequency facilitation at MF synapses. The inhibition of mitochondrial Ca2+ release by CGP37157 significantly reduces the mean magnitude (157.9 ± 6.0%), relative to the control (292.4 ± 30.1%, p = 0.0008; paired t-test). (D) Representative EPSCs recorded before and after treatment of CGP37157 (20 μM) on frequency facilitation elicited by 20 Hz stimulus train at SC synapses. Scale bar: 100 ms, 100 pA. (E) Inhibition of mitochondrial Ca2+ release by CGP37157 has no effect on synaptic facilitation at SC synapses. (F) Summary graph of the mean magnitude of the 10th stimulus train of frequency facilitation at SC synapses. Inhibition of mitochondrial Ca2+ release by CGP37157 does not significantly reduce the mean magnitude (159.9 ± 10.4%), relative to the control (161.7 ± 6.8%, p = 0.776; paired t-test). All data represent mean ± SEM (** p < 0.01, *** p < 0.001, NS: not significant; two-way ANOVA for panels B and E, Student's t-test for panels C and F). The value in parentheses indicates the number of hippocampal neurons (left) and the number of mice (right) used in each experiment.