Fig. 6.
Rescue of the temperature-sensitive block of evoked release at 30°C in csp mutants. When single stimuli (0.2 Hz) failed to evoke neurotransmission in csp null mutants at 30°C, it was possible to partially rescue the temperature-sensitive defect with high-frequency stimulation or high [Ca2+]e. Traces represent typical recordings under current clamp at 30°C. A, Evoked EJPs were blocked in cspU1 null mutants with 0.2 Hz stimulation and 1 mm[Ca2+]e. B, After neurotransmission was blocked, the preparation was stimulated at 10 Hz. The mean amplitude of the first 40 rescued responses was 4.6 ± 1.7 mV (n = 6, ±SEM). C, After neurotransmission at 0.2 Hz was blocked in 1 mm[Ca2+]e, the bath solution was switched to 4 mm[Ca2+]e. Subsequently, stimulation at 0.2 Hz evoked EJPs; the mean amplitude of 12 responses was 19.1 ± 6.1 mV (n = 4).