Figure 6. Blocking glomerular-layer-mediated inhibition alters firing rates and spike latencies in MCs and TCs. a, b, Spikes were measured before and after puffing gabazine in the recorded cell's home glomerulus to limit glomerular-layer-mediated inhibition. c, d, Spike rasters in a MC (c) and TC (d) before (black/red), during (gray/pink), and after (blue) blocking glomerular-layer-mediated inhibition. e, Blocking glomerular-layer-mediated inhibition increased the number of spikes in MCs at all three stimulation intensities (minimum, p = 0.003; middle, p = 0.005; maximum, p = 0.0075) and in TCs at the weakest intensity (minimum, p = 0.0078; middle, p = 0.91; maximum, p = 0.12). f, Blocking glomerular-layer-mediated inhibition increased the firing rate, as measured by the peak of the PSTH, at all three intensities in both MCs (minimum, p = 0.0039; middle, p = 0.011; maximum, p = 0.012) and TCs (minimum, p = 0.0027; middle, p = 0.037; maximum, p = 0.0023). g, Firing rates, however, were more strongly affected by blocking glomerular-layer-mediated inhibition in MCs than in TCs at the strongest two intensities (minimum, p = 0.22; middle, p = 0.014; maximum, p = 0.0039). h, Blocking glomerular-layer-mediated inhibition reduced the latency to the PSTH peak in MCs at the weakest two intensities (minimum, p = 0.007; middle, p = 0.018; maximum, p = 0.56), but did not affect the latency in TCs (minimum, p = 0.43; middle, p = 0.98; maximum, p = 0.48). i, Latency to reliable spiking did not change in TCs after glomerular-layer-mediated inhibition blockade (minimum, p = 0.09; middle, p = 0.13; maximum, p = 0.57); however, in MCs, the timing of responses in all four MCs became reliable at the weakest intensity and latency was reduced at the middle (p = 0.03), but not the maximum (p = 0.75), intensity. j, Spontaneous firing rates of both MCs (p = 0.0034) and TCs (p = 0.0054) increased after puffing gabazine. Data were taken from four MCs and four TCs. Significance was assessed using paired t tests. Asterisks (**) in e–i indicate significant (p < 0.05) differences between MCs and TCs.