Activity-mediated accumulation of potassium induces a switch in firing pattern and neuronal excitability type
Fig 4
Rodent cortical neurons exposed to high extracellular potassium show intermittently interrupted firing.
Example cell; Response of a neuron to a just suprathreshold stimulus in low (3 mM; Top) and high (10 mM; Bottom) extracellular potassium conditions. The suprathreshold current is taken as the current needed to elicit the first spike when injecting a ramp with a shallow slope. The small spikelets visible in the current trace are artifacts resulting from limited capacitive coupling of two channels at the digitizer (i.e., of the action potentials present in the voltage trace), and are not reflective of current injected into the neuron.