Figure 7.

The late phase of exocytosis during prolonged depolarizations is temperature sensitive. The calyx was depolarized for 10 ms (black) or 30 ms (blue) from −80 to 0 mV at room temperature (left) or physiological temperature (right). A, Presynaptic Ca²⁺ currents. A2, Ca²⁺ current inactivation was more pronounced at PT (red) than at RT (black), as seen after scaling the currents by their peak amplitudes. The activation kinetics of the Ca²⁺ current was faster at PT. B, Changes in C_m, membrane resistance (R_m), and series resistance (R_S) in response to 10 and 30 ms depolarizations at RT and PT {depolarizing step pulses for 10 ms (black) or 30 ms (blue) as shown in A1}.