Computation of Time-dependent Probabilities of Vesicle Release and Binding of Neurotransmitters of Postsynaptic Neuron

Abstract

When a postsynaptic neuron receives a spike from the axon, its synapse releases neurotransmitters to the synaptic cleft. The probability of vesicle release depends on the amount of calcium ions. The concentration of calcium ions keeps on changing with time. The opening and closing of these channels is controlled by the calcium ion gates operating at different rates. Similarly, the binding of neurotransmitters to the membrane depends on the number of receptors. The existing literature considers probabilities of vesicle release and binding of neurotransmitters as constants. In practice, these two probabilities are time-dependent. This issue is addressed in this paper and new derivations of the time-varying nature of these two probabilities are obtained from simulation study and analysis. The present investigation of estimation of these two time-dependent probabilities will help to develop improved nanoscale neuronal communication models.