Noise induced multi-mode neural firings in a period adding bifurcation scenario

A series of new firing patterns lying between two kinds of periodic bursting patterns and randomly alternating on the two kinds of periodic bursts, were discovered in the experiment on neural pacemaker and induced by noise in Chay model near each bifurcation point in a period adding bifurcation scenario without chaos, exhibiting multi-mode characteristics that was the signature of autonomous stochastic resonance in neuronal firing. Two endogenous characteristics near each bifurcation point that made noise induce the new firing patterns were identified. One was that there existed critical phase between the trajectories of the two kinds of bursting patterns. The other was that the periods of the two kinds of bursting patterns near each bifurcation point were small.