Neonatal cytomegalovirus exposure decreases prepulse inhibition in adult rats: Implications for schizophrenia

The goal of these studies was to determine whether neonatal viral exposure leads to a deficit in information processing in adulthood, To accomplish th is, rats were infected neonatally with rat cytomegalovirus, and acoustic st artle responses were measured when rats were 120 days old, Acoustic startle was elicited by using a 118-decibel (dB) white noise alone or after a prep ulse 10 dB above background (65 dB); responses were measured after an injec tion of saline or the dopamine agonist apomorphine, Response amplitudes aft er the pulse alone were not significantly altered by either viral exposure or apomorphine, Responses of animals exposed to the prepulse before the pul se were approximately 10% of that after the pulse alone and did not differ between control or virus-exposed animals injected with saline, Animals inje cted with apomorphine exhibited a greater startle response than animals inj ected with saline, and control and virus-exposed rats injected with apomorp hine differed in the magnitude of their responses. Apomorphine attenuated r esponses after the prepulse, and virus-exposed animals exhibited more than twice the attenuation than non-virus-exposed animals, Analysis of prepulse inhibition, calculated from the acoustic startle data, indicated that altho ugh viral exposure alone did not significantly affect information processin g, when virus-injected rats were exposed to apomorphine, a significant 38% decrease in prepulse inhibition was apparent. Findings demonstrate that rat s infected neonatally with rat cytomegalovirus exhibit a deficit in sensori motor gating upon dopamine stimulation, supporting a possible link between viral infection and schizophrenia. (C) 1999 Wiley-Liss, Inc.