Controlling the first-spike latency response of a single neuron via unreliable synaptic transmission

Previous experimental and theoretical studies suggest that first-spike latency is an efficient information carrier and may contain more amounts of neural information than those of other spikes. Therefore, the biophysical mechanisms underlying the first-spike response latency are of considerable interest. Here we present a systematical investigation on the response latency dynamics of a single Hodgkin-Huxley neuron subject to both a suprathreshold periodic forcing and background activity. In contrast to most earlier works, we consider a biophysically realistic noise model which allows us to relate the synaptic background activity to unreliable synapses and latency. Our results show that first-spike latency of a neuron can be regulated via unreliable synapses. An intermediate level of successful synaptic transmission probability significantly increases both the latency and its jitter, indicating that the unreliable synaptic transmission constrains the signal detection ability of neurons. Furthermore, we demonstrate that the destructive influence of synaptic unreliability can be controlled by the input regime and by the excitatory coupling strength. Better tuning of these two factors could help the H-H neuron encode information more accurately in terms of the first-spike latency.