Comparison and interaction of micro and macro scale in living neural networks.

Micro-electrode arrays (MEAs) have enabled the recording of neurons from in vitro tissues with capability of recording activity up to single neuron resolution. Through these recordings, studies have shown that cortical neural networks operate near a continuous, second order phase transition (critical) point.

Local field potentials (LFPs), an average of the activity of several individual neurons near the electrode, provides a coarse-grained representation with critical exponents that match those of mean-field directed percolation. Electrical activity collected at individual neuron precision, fine grained scenario also shows signs of criticality, but the exponents do not match those obtained from the LFP data.

If the system is at a critical point, it should depict scale invariance, calling for a fair comparison. This project aims to compute the critical exponents using data recorded at both the scales simultaneously. Thus, an electrode array consisting of both LFP electrodes and spike electrodes will be constructed and used to record activity at both scales. This data will enable proper comparison and interpretation of the networks behavior at the two scales and whether they show similar exponents.