Figure 6.

Response Changes Associated with Sniff Changes Are Dependent on Behavioral State

(A) Left: example V_m trace from a cell (recorded in a passive mouse) showing strong modulation by the sniff cycle. Right: average V_m as a function of sniff phase during the odor stimulus for this example cell. Shaded area shows SD. Sniff-V_m modulation amplitude is calculated as the difference between the minimal V_m and the value of V_m at the preferred phase, as shown (Figure S11B).

(B) Histogram of sniff-V_m modulation amplitudes across cell-odor pairs recorded in learning mice (n = 38) and passive (n = 42) mice.

(C) Left: experimental setup for tactile stimulation of passive mice. Middle traces show nasal flow and V_m from an example cell: top, control trial (slow sniffing); bottom, tactile stimulus trial (fast sniffing). Right plot shows mean V_m responses for five slow and five fast sniff trials for this example cell. Error bars show SD.

(D) Plot to show mean responses averaged across 5 “slow” and 5 “fast” sniff trials for 30 cell-odor pairs. Red line indicates example in (C).

(E) Scatterplot of absolute response change (between slow and fast sniff trials) versus sniff-V_m modulation amplitude during the odor. Red point shows example in (C).

(F) Experimental set up for controlled nasal flow via double tracheotomy in anesthetized mice. Example traces show nasal flow and V_m trace for one cell: top = slow sniff trial (3.3 Hz); bottom = fast sniff trial (6.6 Hz). Right plot shows mean V_m responses for five slow and five fast sniff trials for this example cell. Error bars show SD.

(G) As for (D), but for “controlled-flow” anesthetized mice (n = 9 cells).

(H) As for (E), but for “controlled-flow” anesthetized mice (n = 9 cells).

(I) As for (E) and (H), but for cell-odor pairs recorded during learning (circles) or task engagement (triangles), where |ΔMID| >20 ms. Yellow line indicates linear regression for these data, while purple line indicates that for pooled data from (E) and (H), which was used to calculated “expected” |Δresponse| values.

(J) Plot comparing deviation of response changes from expected values (see I), for controlled-flow, passive, and behaving mice.

(K) Cumulative histograms to show R² values for correlations between MID and V_m response calculated across trials for each cell odor pair undergoing large MID change in behaving mice (n = 26, gold line and data points) and pooled data (purple line) from controlled-flow (blue data points, n = 9) and passive mice (purple data points, n = 30). Behaving, median = 0.16, IQR = 0.03–0.27; passive and controlled flow, median = 0.07, IQR = 0.02 to 0.15; p = 0.07; rank-sum test; p = 0.09, Brown-Forsythe test.