Figure 4

Recovery from inactivation in neonates and adults. A. Upper trace shows the two-pulse protocol applied in voltage clamp from a holding potential of −60 mV. A hyperpolarising pre-pulse (−100 mV, 100 ms duration) was followed by a depolarising step (−20 mV, 50 ms duration). Next a hyperpolarising ‘recovery’ step of increasing duration (−100 mV, 5 to 200 ms, 5 ms increments, indicated by arrowhead) was applied before a final second depolarising step (−20 mV). Lower two traces show responses recorded for neonatal and adult SDH neurons. Capacitive currents not show. B. Plots of current (normalized to peak current) versus recovery time for neonatal (open circles) and adult recordings (filled circles). Note the faster recovery from inactivation in neonates (* p < 0.05).