Figure 2. The action potential threshold range is an intrinsic membrane property.

In vivo firing patterns of a TRN neuron (ketamine-xylazine anaesthesia) intracellularly recorded during spontaneous synaptic active activity (A, active network) or intracellular current injection (B, current pulse, +1 nA). C, Distribution of voltage thresholds for the previous neuron during both conditions (active network, n = 1404 spikes; current pulses, n = 330 spikes). Note different scales for both conditions. D, Action potential threshold range for TRN neurons driven by intracellular current pulses or spontaneous active network episodes. Means were not significantly different (n = 5, p = 0.248). Circles and grey bars show individual values and means, respectively. Scale bars: A, B, vertical 20 mV, horizontal 50 ms.