Computational modeling of the transfer of electrical signal between neurons, connected through mixed synapses

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Research Paper 01/12/2021
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Computational modeling of the transfer of electrical signal between neurons, connected through mixed synapses

Greta Briliūtė, Mindaugas Šnipas
Int. J. Biosci.19( 6), 163-172, December 2021.
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Synaptic communication between neurons mainly occurs in two different modes of communication – either chemical or electrical. However, the combined evidence from microscopy, immunohistochemistry and electrophysiology experiments confirmed the existence of morphologically mixed synapses, which contains both chemical and electrical synapses. To our knowledge, the putative role of signal transfer through the mixed synapses was not yet addressed in computational neuroscience studies. In this paper, we present data obtained from mathematical and computational modeling experiments. We simulated the transfer of electrical signal between neurons, coupled through a mixed synapse containing an electrical and either an inhibitory (GABA) or excitatory (AMPA or NMDA) chemical synapse. The obtained simulation data revealed that inhibitory effect of GABA synapse is largely obscured by the biphasic response incoming to the postsynaptic neuron from the electrical synapse. In addition, the data showed that some combinations of electrical and an excitatory NMDA (but not APMA) synapses can provide an optimal mixture of conductances to ensure the required firing rates in the postsynaptic neuron. These results may offer at least a partial mechanistic explanation for a relative abundance of mixed synapses containing NMDA synapse, and the rarity of evidence for the existence of other types of mixed synapses.


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