Type iii excitability, slope sensitivity and coincidence detection

Abstract

Some neurons in the nervous system do not show repetitive firing for steady currents. For time-varying inputs, they Are once if the input rise is fast enough. This property of phasic firing is known as Typo III excitability. Typo III excitability has boon observed in neurons in the auditory brainstem (MSO), which show strong phase-locking and accurate coincidence detection. In this paper, we consider a Hodgkin-Huxloy typo model (RM03) that is widely-used for phasic MSO neurons and wo compare it with a modification of it, showing tonic behavior. We provide insight into the temporal processing of those neuron models by moans of developing and analyzing two reduced models that reproduce qualitatively the properties of the exemplar ones. The geometric and mathematical analysis of the reduced models allows us to detect and quantify relevant features for the temporal computation such as nearness to threshold and a temporal integration window. Our results underscore the importance of Typo III excitability for precise coincidence detection.