Fig. 9.

Blocking excitatory transmission increases onset latency of photostimulation-induced spikes, but has little effect on success rate and spike time jitter. A: spike responses of one example cell stimulated with sequences of light pulses at 5, 10, 20, and 40 Hz (repetition rate 0.2 Hz), while excitatory synaptic transmission was pharmacologically blocked by surface application of APV and CNQX. Only responses to first pulses are shown. B: success rate, spike onset latency and spike time jitter averaged across eight cells. Doublet rates were near zero throughout. Values are means ± SD.