Fig. 6: Firing rate depends on the history of the input.
From: Stimulus duration encoding occurs early in the moth olfactory pathway
A LFP is a low-pass filtered image of the receptor current. We used a multicompartmental ORN model to simulate the measured LFP in response to a receptor current IE. The shape of the LFP (Ved, black line) coincided with the shape of the receptor current (blue line) smoothed with an exponential filter with a 10 ms time constant (dashed orange line). B–D Raw recordings of a single ORN's response to three different stimulus durations, recorded with a glass electrode. The blue shaded area indicates the stimulus duration (20 ms, 200 ms, 2 s from B to D). E LFP responses averaged over 26 sensilla. Note that in response to the 2 s stimulus, after the initial downward deflection, LFP went upwards, indicating receptor adaptation, and afterwards continued to go downward again. This was also apparent in (D). F LFP (top) and firing rate (bottom) aligned at the stimulus termination. The LFP after the stimulus offset was identical for the 200 ms and 2 s stimulus, yet their firing rates were dramatically different. The dashed blue lines indicate the response to the 20 ms stimulus but shifted by 50 ms. Then, the LFP time course after the stimulus offset was identical with the 200 ms stimulus, but again, the firing rates greatly differed.
