Stochastic resonance and first passage time for excitable system exposed to underdamped medium

Noise induced Brownian dynamics in underdamped medium is studied numerically to understand the firing time of excitable systems. By considering Brownian particles that move in underdamped medium, we study how the first arrival time behaves for different parameters of the model. We study the first arrival time for both single particle as well as the first arrival time of one particle out a system that has _N_ particles. The present study helps to understand the intercellular calcium dynamics in cardiac tissue at the level of a single microdomain and at a tissue level (ensemble of microdomains). In the presence of time varying signal, we study how signal to noise ratio (SNR) depends on the model parameters. It is showed that the SNR exhibits a pronounced peak at a particular noise strength. The fact that the SNR is amplified as the number of micro domains (_N_) increase shows that the weak periodic signal plays a decisive role in controlling the noise induced dynamics of excitable systems which may also shed light on how to control the abnormal calcium release in a cardiac tissue.