Figure 3.

Categorization of response types. A, Criteria for determining whether a cell was responsive to a given odor. Top, example of excitatory odor response PSTH. The black line is a PSTH of spiking during odorized sniffs. The gray line is a PSTH during unodorized sniffs. Bottom, cumulative spike counts of data from top plot. The red line indicates the first moment when cumulative distributions with and without stimulus become statistically different. B1–B4, PSTHs from examples of each response type to high, low, and low->high stimuli are vertically separated. Arrows indicate which sniffs of the response are statistically compared. Non-significant differences are marked ns, and significant differences are marked with * (Kolmogorov–Smirnov test, p < 0.01). B1, A CT cell-odor pair responded differently to the two concentrations, and this difference is not affected by a concentration step. Example data are the same as Figure 1D. B2, A CI cell-odor pair responded identically to both concentrations, with or without a step. Example data are the same as Figure 1F. B3, ΔC_t cell-odor pairs responded differently to a given concentration after a concentration step. Example data are the same as Figure 2B. B4, Example –ΔC_t response data are the same as Figure 2C. C, Comparisons used to categorize odor-cell pairs. D, Distribution of different response types: CI (n = 49), CT (n = 25), positive ΔC_t (+ΔC_t, n = 28), and negative ΔC_t (–ΔC_t; n = 21). E, Distribution of responses to a second odor for positive ΔC_t (orange), negative ΔC_t (purple), CI (black), and CT (green) cell-odor pairs.