Skip to main content
. 2024 Mar 5;13:e85303. doi: 10.7554/eLife.85303

Figure 6. Effect of sniff frequency on glomerular representation of intermittency (methyl valerate).

For all graphs purple indicates olfactory sensory neurons (OSNs) (OMP-GCaMP6f) and green indicates mitral and tufted (M/T) cells (THY1-GCaMP6f). (A) Heatmap of glomerular intermittency (GI) across trials of 0.2, 0.5, and 0.8 odor intermittency values (colored heatmaps). Glomeruli are sorted based on their GI slope at 2 Hz. Gray bars next to heatmaps indicate the GI slope of each individual glomerulus. (B) % of intermittency encoding cells across sniff frequencies (OMP n=367 glomeruli, 7 mice; THY n=294 glomeruli, 6 mice). (C) GI slope as a function of sniff frequency. (D) Left: GI slope at 8 Hz as a function of GI slope at 2 Hz. Right: The top row shows example photoionization detector (PID) readings from square-wave trials with a fixed odor frequency of 0.83 Hz (5 pulses in 6 s) at intermittency values of 0.2 (blue), 0.6 (red), 0.8 (yellow). The first column represents averages from 2 Hz sniff frequency trials and the second column represents averages from 8 Hz sniff frequency trials. The second row shows example z-score deconvolved dF/F traces of a glomerulus with a low GI slope at 2 sniff frequency Hz and a high GI slope at 8 sniff frequency Hz. The last row shows example z-score deconvolved dF/F traces of a glomerulus with a high GI slope at 2 Hz and a low GI slope at 8 Hz. Black line at y=2 indicates the threshold for determining intermittency (z-score value of 2).

Figure 6.

Figure 6—figure supplement 1. Additional quantification of the effect of sniff frequency on glomerular representation of intermittency.

Figure 6—figure supplement 1.

For all graphs purple indicates olfactory sensory neurons (OSNs) (OMP-GCaMP6f) and green indicates mitral and tufted (M/T) cells (THY1-GCaMP6f). (A) Spatial maps of z-scored response amplitude (open circles) and odor-response correlation (diamonds) as well as spatiotemporal map (T75, filled circles) for methyl valerate (OMP, [M-L,A-P]: μz-score amplitude=[–0.16,–0.06], μodor-response corr=[–0.01,–0.02], μT75r=[–0.56,–0.85]; THY, [M-L,A-P]: μz-score amplitude=[0.06,0.17], μodor-response corr=[–0.06,–0.02], μT75r=[–0.61,–0.82]), left, and 2-heptanone (OMP, [M-L,A-P]: μz-score amplitude=[0.19,0.43], μodor-response corr=[0.23,0.38], μT75r=[–0.40,–0.51]; THY, [M-L,A-P]: μz-score amplitude=[0.21,0.31], μodor-response corr=[–0.03,0.14], μT75r=[–0.51,–0.63]), middle. Example spatial maps of t75 and z-score amplitude for OMP-GCaMP6f and THY1-GCaMP6f animals when presented with methyl valerate or heptanone, right. (B) Histogram of the change in glomerular intermittency (GI) from odor intermittency 0.2 to odor intermittency 0.8 based on the linear regression fit of GI vs odor intermittency per glomerulus. (C) Average GI as a function of odor intermittency for sniff frequencies of 2–8 Hz (light to dark shades). (D) GInHz-GI2Hz per glomerulus for each intermittency value for methyl valerate, top and 2-heptanone, bottom. (E) Linear classifier performance (accuracy) over 240 glomeruli when trained on trials of four different sniff frequencies (2, 4, 6, 8 Hz) when presented with methyl valerate. 60 iterations (20 times threefold) per classifier. OMP: exponential plateau fit, 2 Hz: Y=0.91–(0.34)*(e–0.03x), r2=0.55; 8 Hz: Y=0.86–(0.32)*(e–0.03x), r2=0.42. THY: exponential plateau fit, 2 Hz: Y=0.92–(0.5)*(e–0.05x), r2=0.66; 8 Hz: Y=0.93–(0.38)*(e–0.04x), r2=0.61.
Figure 6—figure supplement 2. Effect of sniff frequency on odor correlation, sniff correlation, air response, and odor response.

Figure 6—figure supplement 2.

For all graphs purple indicates olfactory sensory neurons (OSNs) (OMP-GCaMP6f) and green indicates mitral and tufted (M/T) cells (THY1-GCaMP6f). (A) Top: Methyl valerate. Bottom: 2-Heptanone. Left: Average maximum cross-correlation between glomerular response and photoionization detector (PID) reading across sniff frequencies (Spearman correlation, p<0.0001). Right: Average maximum cross-correlation between glomerular response and pressure sensor reading (sniff measurement) across sniff frequencies (Spearman correlation, p<0.0001). (B) Top: Methyl valerate. Bottom: 2-Heptanone. Left: Average glomerular deconvolved ΔF/F prior to odor presentation (Spearman correlation, p<0.0001). Right: Average glomerular deconvolved ΔF/F during odor presentation (Spearman correlation, p>0.05) (methyl valerate: OMP n=367 glomeruli, 7 mice; THY n=294 glomeruli, 6 mice; heptanone: OMP n=241 glomeruli, 6 mice; THY n=271 glomeruli, 6 mice; n=45 trials per sniff frequency, total n=180 trials).