. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. mM perchlorate * S -V 2 "* a i' "*> a 1 S s I "§ 25 mM perchlorate •44 mM Na • 440 mM Na ' II 10 100 316 mMClO. Figure 1. Perchlorate reduces gating and untie currents. The records are for steps from a —80 mV ho/ding potential. The gray records are to +20 ml', thf black, to —5 mV. The records on the right are shown at the expanded timebase. The graph shows the maximum Na conductance, normalised to the value obtained in Cl artificial seawater. a function of ClOj concentration fo
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. mM perchlorate * S -V 2 "* a i' "*> a 1 S s I "§ 25 mM perchlorate •44 mM Na • 440 mM Na ' II 10 100 316 mMClO. Figure 1. Perchlorate reduces gating and untie currents. The records are for steps from a —80 mV ho/ding potential. The gray records are to +20 ml', thf black, to —5 mV. The records on the right are shown at the expanded timebase. The graph shows the maximum Na conductance, normalised to the value obtained in Cl artificial seawater. a function of ClOj concentration for ftro different Na concentrations. C1O4 was 540. They were internally perfused with either a Cs perfusion fluid (pf) containing 240 Cs, 150 glutamate, 50 F. 750 sucrose, and 40 HEPES, pH ; or a K pf containing 200 K. 80 Na, 190 glutamate. 50 F, 550 glycine, and 40 HEPES, pH Experiments were performed at 3-4°C. The axons were voltage- clamped at a —80 mV holding potential. Currents were recorded with a p/4 protocol (7), filtered at 40 kHz and sampled at 100 kHz. The records presented are averaged over 64 cycles. The tracings at the left of the figure were made in 44 mM Na asw, with Cs pf inside. Current traces for pulses to -5 mV (black) and +20 mV (gray) are shown on two different time bases. The top set of records is in Cl asw. Replacing 25 mM of Cl in the asw with C1O4 almost eliminated both the inward ionic current and the early outward gating current, and mM C1O4 had hardly any effect. Intermediate concentrations of C1O4 partially reduced both ionic and gating currents proportionally (not shown), with reduction of the sodium conductance to one half at about 16 mM. The prepa- ration recovered partially when returned to ClO4-free solutions; but the recovery was less at higher C1O4 concentrations or after longer exposure times. The effects of C1O4 on the maximum sodium conductance are summarized in the graph at the right of the figure. In full Na asw,
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
