Format

Send to

Choose Destination
Front Hum Neurosci. 2010 Nov 2;4:196. doi: 10.3389/fnhum.2010.00196. eCollection 2010.

Mechanisms for Phase Shifting in Cortical Networks and their Role in Communication through Coherence.

Author information

1
Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen Nijmegen, Netherlands.

Abstract

In the primate visual cortex, the phase of spikes relative to oscillations in the local field potential (LFP) in the gamma frequency range (30-80 Hz) can be shifted by stimulus features such as orientation and thus the phase may carry information about stimulus identity. According to the principle of communication through coherence (CTC), the relative LFP phase between the LFPs in the sending and receiving circuits affects the effectiveness of the transmission. CTC predicts that phase shifting can be used for stimulus selection. We review and investigate phase shifting in models of periodically driven single neurons and compare it with phase shifting in models of cortical networks. In a single neuron, as the driving current is increased, the spike phase varies systematically while the firing rate remains constant. In a network model of reciprocally connected excitatory (E) and inhibitory (I) cells phase shifting occurs in response to both injection of constant depolarizing currents and to brief pulses to I cells. These simple models provide an account for phase-shifting observed experimentally and suggest a mechanism for implementing CTC. We discuss how this hypothesis can be tested experimentally using optogenetic techniques.

KEYWORDS:

attention; gamma oscillations; phase locking; phase shifting; synchrony

Supplemental Content

Full text links

Icon for Frontiers Media SA Icon for PubMed Central
Loading ...
Support Center