Role of Pyramidal Cell M-current in Weak Pyramidal/Interneuronal Gamma Cluster Formation

In the cortex gamma oscillations, generated in the networks consisting of pyramidal cells and interneurons, are typically irregular and sparse. Taking into account differences in the firing frequencies of pyramidal cells and interneurons, it is possible to conclude that a probable way of modelling of these gamma features is generation of the oscillations by alternating firing of the pyramidal cell clusters. Muscarine-sensitive potassium current (M-current) together with AHP-current plays important role in intrinsic dynamics of the pyramidal cells. In particular, it dampens the excitability (decreasing the spiking state range in the parameter space) and changes the excitability type of the pyramidal cells. These crucially act on the cluster formation process in the pyramidal subnetwork altering the number of clusters and, thus, coherence of the gamma rhythm.