Geometric analysis of synchronization in neuronal networks with global inhibition and coupling delays.

Philos Trans A Math Phys Eng Sci

Department of Applied Mathematics, Centre for Theoretical Neuroscience, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.

Published: September 2019

We study synaptically coupled neuronal networks to identify the role of coupling delays in network synchronized behaviour. We consider a network of excitable, relaxation oscillator neurons where two distinct populations, one excitatory and one inhibitory, are coupled with time-delayed synapses. The excitatory population is uncoupled, while the inhibitory population is tightly coupled without time delay. A geometric singular perturbation analysis yields existence and stability conditions for periodic solutions where the excitatory cells are synchronized and different phase relationships between the excitatory and inhibitory populations can occur, along with formulae for the periods of such solutions. In particular, we show that if there are no delays in the coupling, oscillations where the excitatory population is synchronized cannot occur. Numerical simulations are conducted to supplement and validate the analytical results. The analysis helps to explain how coupling delays in either excitatory or inhibitory synapses contribute to producing synchronized rhythms. This article is part of the theme issue 'Nonlinear dynamics of delay systems'.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6661332PMC
http://dx.doi.org/10.1098/rsta.2018.0129DOI Listing

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