Firing properties of the LTS cell type.A, Example of spontaneous activity in an LTS neuron; this neuron exhibited the highest rate of spontaneous activity of any LTS neuron we recorded. B, Rebound spike fired after a hyperpolarizing current pulse delivered from rest. The baseline potential was −60 mV. C, An example of an LTS neuron that could fire APs throughout a depolarizing current pulse. The baseline potential was −69 mV, maintained by continuous injection of −0.02 nA. This cell is the same as the one shown in A.D, APs evoked in an LTS cell by a current pulse delivered from rest (top, baseline potential of −47 mV) and a hyperpolarized potential (bottom, baseline potential of −67 mV maintained by continuous injection of −0.06 nA). All of the cells in this figure were recorded in zebra finch brain slices.