Fig. 3. Effects of prior exposure to anoxic conditions on whole-cell K+ currents in locust neurons. Outward K+ currents obtained with voltage steps made from a holding potential of –60 mV in 10 mV increments from –80 mV to 40 mV. (A) Representative whole-cell voltage-clamp recordings from neurons in locust metathoracic ganglion slices of a control and an anoxia-treated animal at 25°C. (B) Mean I/V plots of control (N=9) and anoxia-treated (N=10) neurons at 25°C. Prior anoxia treatment significantly affected the I/V relationship (two-way ANOVA with Tukey pairwise multiple-comparison test, F=2.98, d.f.=12, P<0.001). Following anoxia, less current was evoked with each voltage step compared with control recordings. Values are means ± S.E.M. (C) Mean activation curves of whole-cell K+ currents recorded from control and anoxia-treated neurons at 25°C. G is the whole-cell conductance; Gmax is the maximal conductance at a voltage step to 40 mV. V1/2, the test potential at which there is half-maximal conductance, of control cells was –10.55±1.27 mV and did not differ from the V1/2 of –7.27±2.01 mV for anoxia-treated cells (t-test, t=1.34, P=0.20, d.f.=17). Asterisks indicate a significant difference between control and experimental groups (P<0.05).
