Effects of TSP4 on the depolarization-induced Ca2+ transient. A, Sample traces show the influence of TSP4 on recovery of the Ca2+ transient induced by neuronal depolarization with KCl (50 mM K+ for 0.3 s). Black and gray lines show single exponential fit of the recovery of [Ca2+] i. B, Summary data show TSP4 decreased [Ca2+] i recovery following depolarization in small-sized neurons. C, Sample trace shows the effect of NCX inhibitor, YM 244769 (5 μM), on recovery of the Ca2+ transient induced by neuronal depolarization with KCl solution. D, Summary data show that YM 244769 did not change [Ca2+] i recovery following depolarization (paired t-test). E, Sample trace shows the effect of mitochondrial Ca2+ uniporter inhibitor, Ru360 (10 μM), and mitochondrial NCX inhibitor, CGP 37157 (10 μM), on recovery of the Ca2+ transient induced by neuronal depolarization with KCl solution. F, Summary data show that Ru360 and CGP 37157 did not change [Ca2+] i recovery following depolarization (paired t-test). * p < 0.05, *** p < 0.001.