Figure 4.

Precision of spike timing varies among MT cells. A, Spike rasters and instantaneous firing rates (mean ± SEM, black over gray shading), as well as preodor instantaneous firing rate (green), for two MT cells. Blue dots in spike rasters highlight the first spike after each sniff with an instantaneous firing rate that exceeds the mean preodor firing rate by one SD; the time of this first spike was the response “onset time” after each sniff. Horizontal blue bar indicates the mean ± SD of onset time across trials. Onset precision was defined as the SD of the onset time. In this example, the mean onset times for the two cells were similar, but one cell (top) had an SD of 7 ms, while the other had an SD of 29 ms. B, Distribution of precision times for 35 MT cells. Precision values ranged from 2 to 44 ms (median, 15 ms). C, There was no relationship between onset precision and baseline firing rate. Precision (SD of onset time) is plotted against mean baseline interspike interval for 35 MT cells. The two cells in A are highlighted in red; both had similar baseline firing rates (∼10 Hz).