Figure 6. Bell-shaped frequency dependence of NO release.

A, time courses of NO signal intensity changes at the PF–Purkinje cell synapse in response to 60 BSs applied at 0.25, 1 or 4 Hz. Representative result of five experiments. B, peak values of NO release after 60 BSs applied at different frequencies. Mean ± s.e.m. (n = 5). C, increases in intracellular Ca²⁺ concentration within the fine dendrites of Purkinje cells at the end of 60 BSs at various frequencies (n = 7).