Figure 4.

Artificial Strengthening of Spoke-to-Hub Electrical Connections

(A–C) The heterologous expression of gap junction proteins in CEP and RIH, expected to strengthen electrical coupling α₁ between these neurons (A; +CEP-RIH), enhanced the response to a 2 s nose touch stimulus in both RIH (B) and the second spoke, FLP (C), relative to the native circuit.

(D–F) When the CEP neuron is inactivated, this heterologous expression (D; +CEP-RIH) further inhibited RIH (E) and the active spoke, FLP (F), as predicted by the model (Figures 2D and 2E).

(G–I) When the FLP neuron is inactivated, heterologous expression predicted to increase coupling to the active input CEP (G; +CEP-RIH) increased hub, RIH, activity (H) but inhibited the active spoke, CEP (I), as predicted by the model (Figures 2D and 2E).

Numbers in each bar represent the sample size. Error bars represent SEM. ΔR is computed as the mean percent ratio change 10 s after stimulus onset compared to 10 s just prior to the stimulus onset. Averaged traces include SEM as shaded backgrounds. Upward-pointing arrows at bottom of traces indicate stimulus onset time. ^***p < 0.001 by two-tailed unpaired t test. See also Figures S1 and S2.