Alpha-Frequency Rhythms Desynchronize over Long Cortical Distances: A Modeling Study

Neocortical networks of excitatory and inhibitory neurons can display alpha()-frequency rhythms when an animal is in a resting or unfocused state. Unlike some - and -frequency rhythms, experimental observations in cats have shown that these -frequency rhythms need not synchronize over long cortical distances. Here, we develop a network model of synaptically coupled excitatory and inhibitory cells to study this asynchrony. The cells of the local circuit are modeled on the neurons found in layer V of the neocortex where -frequency rhythms are thought to originate. Cortical distance is represented by a pair of local circuits coupled with a delay in synaptic propagation. Mathematical analysis of this model reveals that the h and T currents present in layer V pyramidal (excitatory) cells not only produce and regulate the -frequency rhythm but also lead to the occurrence of spatial asynchrony. In particular, these inward currents cause excitation and inhibition to have nonintuitive effects ...

• Type: Journal
• Year: 2000
• Where: JCNS
• Authors: Stephanie R. Jones, David J. Pinto, Tasso J. Kaper, Nancy Kopell
• Keywords: -frequency Rhythm, Cortical Distance, Excitatory, JCNS 2000