Fig. 8.
Four example recordings obtained in awake mice by the automated patch-clamp system. A: shown are the responses of 2 neurons to hyperpolarizing and depolarizing current steps and 5-s-long recordings of spontaneous activity in these same neurons as the mice ran at the speeds indicated. Note the recording stability despite animal locomotion. Vm, membrane potential. B: the frequency response of 2 neurons were probed by injecting a swept-sine current stimulus (black; 0–15 Hz over 15 s). The dark gray neuron responded as a low-pass filter and the lighter gray neuron as a band-pass (resonant) filter. This is seen more clearly by considering their impedance profiles (bottom), constructed by taking the ratio of the Fourier transform magnitudes of the responses and the stimulus.