Alterations in brain connectivity due to plasticity and synaptic delay

TL;DR

This study investigates how synaptic delays influence brain connectivity and synchronization in a Hodgkin-Huxley neuronal network with Hebbian plasticity, revealing that delays induce complex topologies and affect synchronization.

Contribution

It introduces a detailed analysis of synaptic delay effects on plasticity and synchronization in a Hodgkin-Huxley network, highlighting non-trivial topologies and delay-dependent synchronization.

Findings

Increased delay alters synaptic strength distribution.

Synchronization occurs only at small delays.

Network topology becomes complex with larger delays.

Abstract

Brain plasticity refers to brain's ability to change neuronal connections, as a result of environmental stimuli, new experiences, or damage. In this work, we study the effects of the synaptic delay on both the coupling strengths and synchronisation in a neuronal network with synaptic plasticity. We build a network of Hodgkin-Huxley neurons, where the plasticity is given by the Hebbian rules. We verify that without time delay the excitatory synapses became stronger from the high frequency to low frequency neurons and the inhibitory synapses increases in the opposite way, when the delay is increased the network presents a non-trivial topology. Regarding the synchronisation, only for small values of the synaptic delay this phenomenon is observed.