Dynamic properties of the responses of single neurones in the cochlear nucleus of the rat.

Abstract

The dynamic properties of unit responses to amplitude-modulated tones were studied using modulation with pseudorandom noise and described by cross-covariance and integrated cross-covariance functions between the discharge rate and the modulation. Under the experimental conditions used, these 2 functions were valid approximations of the system''s impulse and step response functions, respectively. On the basis of their impulse response functions units were classified into 2 groups: type I with a low adaptation and type II with a large degree of adaptation and a damped oscillation in their impulse response functions. The response pattern of the type II units was most likely the result of a negative feed-back striving to keep the discharge rate at a nearly constant level. The cross-covariance functions remained unchanged during long duration recordings from the same unit.