Figure 3.

Inhibition of electrical conduction by CBX and βGA. Representative responses of V_m at Site 2 recorded 500 µm from current injection at Site 1 under control conditions and during exposure to GA derivatives. Indicated treatments began at the time of the recordings illustrated. (A) Control responses to ±0.1–3 nA. (B) During 30 µM CBX, V_m responses to ±1 nA were maintained with no effect on baseline V_m. (C) During exposure to 100 µM CBX, V_m initially hyperpolarized and then depolarized; after ∼5 min, V_m responses to ±1 nA were inhibited such that only residual capacitance spikes remained. (D) Summary data (means ± SE; n= 4) for experiments illustrated in A–C. Responses during 30 µM CBX were not different from control (C). Electrical coupling was abolished during 100 µM CBX. *Significantly different from control, P < 0.05. (E) Responses to ±0.1–3 nA were maintained during 10 µM βGA. (F) During 30 µM βGA, V_m responses to ±1 nA were inhibited within ∼10 min. (G) During 40 µM βGA, V_m responses to ±1 nA were inhibited within ∼5 min. (H) Summary data (means ± SE; n= 5) for experiments in E–G. Responses during 10 µM βGA were not different from control (C). Electrical coupling was abolished with ≥30 µM βGA. *Significantly different from control, P < 0.05.