  First spike latency following stimulus onset is of significant physiological
relevance. Neurons transmit information about their inputs by transforming them
into spike trains, and the timing of these spike trains is in turn crucial for
effectively encoding that information. Random processes and uncertainty that
underly neuronal dynamics have been shown to prolong the time towards the first
response in a phenomenon dubbed noise-delayed decay. Here we study whether
Hodgkin-Huxley neurons with a tunable intensity of intrinsic noise might have
shorter response times to external stimuli just above threshold if placed on a
scale-free network. We show that the heterogeneity of the interaction network
may indeed eradicate slow responsiveness, but only if the coupling between
individual neurons is sufficiently strong. Increasing the average degree also
favors a fast response, but it is less effective than increasing the coupling
strength. We also show that noise-delayed decay can be offset further by
adjusting the frequency of the external signal, as well as by blocking a
fraction of voltage-gated sodium or potassium ion channels. For certain
conditions, we observe a double peak in the response time depending on the
intensity of intrinsic noise, indicating competition between local and global
effects on the neuronal dynamics.
