Effects of chronic olanzapine and haloperidol differ on the mouse N1 auditory evoked potential.

Auditory evoked potentials have been used in a variety of animal models to assess information-processing impairments in schizophrenia. Previous mouse models have primarily employed a paired click paradigm to assess the transient measures of auditory gating. The current study uses stimulus trains at varied interstimulus intervals (ISI) between 0.25 and 8 s in mice to assess the effects of chronic olanzapine and haloperidol on auditory processing. Data indicate that olanzapine increases the amplitude of the N40, P80, and P20/N40 components of the auditory evoked potential, whereas haloperidol had no such effect. The ISI paradigm also allowed for an evaluation of several components of the mouse evoked potential to assess those that display response properties similar to the human P50 and N100. Data suggest that the mouse N40 displays an ISI response relationship that shares characteristics with the human N100, whereas the P20 appears more consistent with the human P50 across the ISI range evaluated in this task. This study suggests that olanzapine may help improve N100 impairments seen in schizophrenia, while haloperidol does not.