Figure 2.

Effect of analog filtering on the action potential waveforms of identified dopaminergic substantia nigra neurons. A, Waveform averages of the same 150 action potentials of a single neuron filtered with either standard bandpass settings (300–5000 Hz, dashed line) or wideband settings (0.3–5000 Hz, solid line). Measurement used for biphasic action potential duration shown in bottom right. B, Mean biphasic action potential durations of calbindin-negative (CB-ve) and calbindin-positive (CB+ve) dopaminergic neurons according to standard bandpass filtering (left) and wideband filtering (right). C, Population histograms for biphasic action potential durations filtered with either standard settings (left) or wideband settings (right).