Figure 2.
Electrophysiological recordings from a motoneuron following 13 DIV. (a) Voltage-clamp recording. Current flow in the patched cell was measured in response to a stepwise increase in voltage across 10×500 millisecond pulses. Stimulation began with a 10 mV increase from a –70 mV resting potential (–60 mV net) and increased to +30 mV over the course of the program. (b) Current-clamp recording. Voltage change (and therefore action potential presence) was measured in response to a stepwise increase in current. Current injection began with a 10 pA increase from baseline, and increased by a further 10 pA with each subsequent pulse for 10×500 millisecond pulses. Action potentials were first observed during 40 pA current injection. (c) Continuous gap-free recording of a motoneuron maintained in current-clamp at –70 mV. 200 μM glutamate was added to the culture medium after 35 seconds recording.
