 Burst firing

Burst firing is a pattern in which a neuron emits groups of closely spaced action potentials, separated by longer gaps. A burst criterion must specify the relevant timescale: an interspike interval counted as short in one preparation need not define a burst in another. A burst can arise from intrinsic membrane dynamics, coordinated inputs, or their interaction.

An invented spike train makes the distinction quantitative. Put five spikes at $0,10,20,30,40$ milliseconds and five more at $500,510,520,530,540$ milliseconds. There are ten spikes in the one-second observation window, as in a $10{\mathrm{s}}^{-1}$ tonic train, but most within-cluster interspike intervals are $10$ milliseconds and the gap between clusters is $460$ milliseconds. Mean count rate alone loses this organization.

A 2018 study combined recordings, pharmacology and modelling of lateral habenula neurons in rodent preparations. It linked bursting under its experimental conditions to NMDA receptors and T-type calcium channels, and manipulated firing mode by changing membrane conditions.^[ref] This is a mechanism tested in particular cells and preparations, not a definition requiring those exact channels in every bursting neuron.