A MODEL FOR BINAURAL RESPONSE PROPERTIES OF INFERIOR COLLICULUS NEURONS - II - A MODEL WITH INTERAURAL TIME DIFFERENCE-SENSITIVE EXCITATORYAND INHIBITORY INPUTS AND AN ADAPTATION MECHANISM

The inferior colliculus (IC) model of Cai et al. [J. Acoust. Sec. Am. 103, 475-493 (1998)] simulated the binaural response properties of low -frequency IC neurons in response to various acoustic stimuli. This mo del, however, failed to simulate the sensitivities of IC neurons to dy namically changing temporal features, such as the sharpened dynamic in teraural phase difference (TPD) functions. In this paper, the Cai et a l. (1998) model is modified such that an adaptation mechanism, viz., a n additional channel simulating a calcium-activated, voltage-independe nt potassium channel which is responsible for afterhyperpolarization, is incorporated in the IC membrane model. Simulations were repeated wi th this modified model, including the responses to pure tones, binaura l beat stimuli, interaural phase-modulated stimuli, binaural clicks, a nd pairs of binaural clicks. The discharge patterns of the model in re sponse to current injection were also studied and compared with physio logical data. It was demonstrated that this model showed all the prope rties that were simulated by the Cai et nl. (1998) model. In addition, it showed some properties that were not simulated by that model, such as the sharpened dynamic IPD functions and adapting discharge pattern s in response to current injection. (C) 1998 Acoustical Society of Ame rica.