SYNCHRONIZATION OF BIOLOGICAL NEURONS WITH CONDUCTION DELAYS

Document Type

Presentation

Start Date

22-10-2010 3:00 PM

End Date

22-10-2010 4:30 PM

Description

Long range synchrony occurs by locking to a common input or via reciprocal coupling (Tort et al., 2007). It is an open question as to how stable synchronization properties of neural circuits are sustained over long distances. We analyze two reciprocally coupled oscillatory neurons with conduction delays. We use Phase Resetting Curves (PRCs) generated under the assumption of pulsatile coupling to predict what phase-locked solutions will be exhibited in the neuronal circuit with delays. We test our predictions in circuits of two model neurons as well as in hybrid circuits constructed with two entorhinal cortex stellate cells (or two pyramidal cells) coupled via dynamic clamp. We found that the skewness of PRC is a critical feature that determines the locking pattern of homogeneous two-neuron model circuits in the presence of delays. The most robust synchronization for two heterogeneous neurons is predicted for excitatory coupling with delays that fall in a region of the PRC called the causal limit, in which the arrival of a delayed spike triggers a spike in the postsynaptic neuron almost immediately. Experimental tests confirmed the prediction that tight synchrony would be observed for delays between one half and one whole intrinsic period of the component neurons.

Comments

See abstract book page 69

This document is currently not available here.

Share

COinS
 
Oct 22nd, 3:00 PM Oct 22nd, 4:30 PM

SYNCHRONIZATION OF BIOLOGICAL NEURONS WITH CONDUCTION DELAYS

Long range synchrony occurs by locking to a common input or via reciprocal coupling (Tort et al., 2007). It is an open question as to how stable synchronization properties of neural circuits are sustained over long distances. We analyze two reciprocally coupled oscillatory neurons with conduction delays. We use Phase Resetting Curves (PRCs) generated under the assumption of pulsatile coupling to predict what phase-locked solutions will be exhibited in the neuronal circuit with delays. We test our predictions in circuits of two model neurons as well as in hybrid circuits constructed with two entorhinal cortex stellate cells (or two pyramidal cells) coupled via dynamic clamp. We found that the skewness of PRC is a critical feature that determines the locking pattern of homogeneous two-neuron model circuits in the presence of delays. The most robust synchronization for two heterogeneous neurons is predicted for excitatory coupling with delays that fall in a region of the PRC called the causal limit, in which the arrival of a delayed spike triggers a spike in the postsynaptic neuron almost immediately. Experimental tests confirmed the prediction that tight synchrony would be observed for delays between one half and one whole intrinsic period of the component neurons.