(A-C) Varying the width of the distribution of responsive PNs (simulating changes in odor concentration, see Figures 5K and 7A) had no effect on oscillation frequency. (A) Width was varied by adjusting the threshold level for activating PNs. (B) Adjusting the threshold greatly altered overall input to the modeled AL network. (C) The oscillation frequency remained constant despite simulated changes in odor concentration.
(D-F) Varying the height of the distribution of responsive PNs (simulating adaptation in ORNs) caused changes in oscillation frequency. (D) Height was altered by scaling the response intensity of activated PNs. (E) Adjusting the intensity greatly altered overall input to the modeled AL network, as in [B]. (F) The frequency of LFP oscillations decreased when adaptation of ORNs was simulated.
(G-H) Model EAG (green) and LFP response (black) when ORNs are permitted to adapt. Adaptation alone is sufficient to shift the oscillatory frequency (power spectra for early and late oscillations shown in H).
(I-J) Model EAG (green) and LFP response (black) when ORNs are not permitted to adapt. Without adaptation oscillation frequency remains constant (power spectra in J).