Figure 7.
Response Changes in Absence of Applied Odor Are Dependent on Sniff-Locked Input
(A) Left: example traces showing spontaneous fast sniff bouts during inter-trial interval and concurrent Vm traces. Spikes are clipped for display. Right: histogram to show distribution of Vm changes during spontaneous rapid sniffs (>5 Hz) for 26 MTCs in which there were >20 fast sniffs. Black bars indicate cases showing a significant change in Vm.
(B) Scatterplot of absolute Vm change (between slow and fast sniffs) against sniff-Vm modulation amplitude. Gray dots show data from passive mice (n = 10); gold dots show data from behaving mice (n = 16).
(C) Plot to show differences between actual and expected Vm change (expected Vm change is calculated based on sniff-Vm modulation amplitudes using linear regression in B).
(D) Morphologies of a reconstructed TC (left) and MC (right), with mean Vm as a function of sniff phase shown below (shaded area = SD). Phase preferences are indicated with dotted lines. Bb, brain border; GL, glomerular layer; EPL, external plexiform layer; MCL, mitral cell layer.
(E) Phase plot to show preferences of five reconstructed MCs (red) and four reconstructed TCs (blue). 0/2π radians = inhalation onset.
(F) Vm change (between fast and slow sniffs) as a function of the sniff-phase preference of the cell. Black filled dots show significant Vm changes. Red-shaded region shows phases that best encompass hyperpolarizing cells (putative MCs), and remaining blue region best encompasses depolarizing cells (putative TCs). Symbols show phase preferences of morphologically recovered cells: red triangles, MCs; blue diamonds, TCs.
(G) Comparison of Vm change due to fast sniffing for putative TCs and MCs defined by the phase boundaries shown in (F). pMCs, median ΔVm = −0.39 mV, IQR = −0.66 to −0.17 mV, n = 16; pTCs, median ΔVm = 0.19 mV, IQR = 0.08 to 0.66 mV, n = 11; p = 9 × 10−4, rank-sum test.