Selective Participation of Single Cortical Neurons in Neuronal Avalanches.

Neuronal avalanches are scale-invariant neuronal population activity patterns in the cortex that emerge in the awake state and during balanced excitation and inhibition. Theory and experiments suggest that avalanches indicate a state of cortex that improves numerous aspects of information processing by allowing for the transient and selective formation of local as well as system-wide spanning neuronal groups. If avalanches are indeed involved with information processing, one might expect that single neurons would participate in avalanche patterns selectively.

Irregular spiking of pyramidal neurons organizes as scale-invariant neuronal avalanches in the awake state.

Spontaneous fluctuations in neuronal activity emerge at many spatial and temporal scales in cortex. Population measures found these fluctuations to organize as scale-invariant neuronal avalanches, suggesting cortical dynamics to be critical. Macroscopic dynamics, though, depend on physiological states and are ambiguous as to their cellular composition, spatiotemporal origin, and contributions from synaptic input or action potential (AP) output.

Simultaneous multi-electrode array recording and two-photon calcium imaging of neural activity.

A complete understanding of how brain circuits function will require measurement techniques which monitor large-scale network activity simultaneously with the activity of local neural populations at a small scale. Here we present a useful step towards achieving this aim: simultaneous two-photon calcium imaging and multi-electrode array (MEA) recordings. The primary challenge of this method is removing an electrical artifact from the MEA signals that is caused by the imaging laser.