With inhibitory synaptic inputs unblocked, some Purkinje cells fire in a repeating bimodal pattern; ouabain block of Na⁺/K⁺ pumps switches these cells into the trimodal firing pattern and then a continuous burst mode.

<p><i>A</i>, Whole cell patch clamp recording from a Purkinje cell (with GABA synaptic inputs intact/unblocked) in control and following the application of 2.5 µM ouabain. The red arrow denotes the time at which we feel that ouabain starts to modify Purkinje cell firing. Panels <i>B</i>, <i>C</i>, <i>D</i>, and <i>E</i> correspond to the labelled parts of panel <i>A</i>. In control, the Purkinje cell activity is in the repeating bimodal pattern (<i>B</i>). Following the addition of ouabain, the firing pattern is switched from bimodal to trimodal (<i>C</i>) and then transitions into continuous bursting (<i>D</i>). After a period, this bursting acquires a gradient of depolarization and ultimately converges upon a somatic depolarization block, in which the only deflections observed are those of Ca²⁺ spikes that have travelled into the soma from the dendritic arborisation (<i>E</i>). <i>Panel A scaling is encoded in the first scale bar (20 mV, 100 s). Panel B scaling is encoded in the second scale bar (20 mV, 5 s). The scaling of panels C, D and E is encoded in the third scale bar (20 mV, 5 s)</i>.