A new regime for highly robust gamma oscillation with co-exist of accurate and weak synchronization in excitatory-inhibitory networks.

Author: Wang Z1, Fan H2, Han F1.
1College of Information Science and Technology, Donghua University, Shanghai, 201620 China. 2Glorious Sun School of Business and Management, Donghua University, Shanghai, 200051 China.
Conference/Journal: Cogn Neurodyn.
Date published: 2014 Aug
Other: Volume ID: 8 , Issue ID: 4 , Pages: 335-44 , Special Notes: doi: 10.1007/s11571-014-9290-4 , Word Count: 204

A great number of biological experiments show that gamma oscillation occurs in many brain areas after the presentation of stimulus. The neural systems in these brain areas are highly heterogeneous. Specifically, the neurons and synapses in these neural systems are diversified; the external inputs and parameters of these neurons and synapses are heterogeneous. How the gamma oscillation generated in such highly heterogeneous networks remains a challenging problem. Aiming at this problem, a highly heterogeneous complex network model that takes account of many aspects of real neural circuits was constructed. The network model consists of excitatory neurons and fast spiking interneurons, has three types of synapses (GABAA, AMPA, and NMDA), and has highly heterogeneous external drive currents. We found a new regime for robust gamma oscillation, i.e. the oscillation in inhibitory neurons is rather accurate but the oscillation in excitatory neurons is weak, in such highly heterogeneous neural networks. We also found that the mechanism of the oscillation is a mixture of interneuron gamma (ING) and pyramidal-interneuron gamma (PING). We explained the mixture ING and PING mechanism in a consistent-way by a compound post-synaptic current, which has a slowly rising-excitatory stage and a sharp decreasing-inhibitory stage.
Balanced networks; Gamma oscillation; Heterogeneity; Synapse

PMID: 25009675