Gap induced pre-pulse inhibition (Gap-PPI) of acoustic startle reflex has been used as a measurement of tinnitus in animal models. However, whether this test is sensitive to detect tinnitus in humans is still unclear. Based on the testing procedure used in animal studies, a human subject testing method was formulated and conducted to investigate if a similar result could be found in tinnitus patients. Audiologic and tinnitus assessments and acoustic startle reflex measurements were performed on seven tinnitus subjects and nine age matched subjects without tinnitus. There was no significant difference found between the control and tinnitus group on the Gap-PPI across the frequencies evaluated. The amplitude of the startle response in the tinnitus group with normal hearing thresholds was significantly higher than the control group and those with tinnitus and hearing loss. This preliminary result suggests that hyperexcitability in the central auditory system may be involved in tinnitus. There was no correlation between hearing thresholds and the increased amplitude of startle response.

Although some traditional animal models for studying schizophrenia have been wildly used,many problems remain in their credibility and validity.We propose that structured animal models with the integration of multiple symptom-inducing factors are be better in simulating the symptoms of schizophrenia and represent the new direction of the future ani-mal-model development.In this article,we review previous studies in this line of research and emphasize the importance of combining the behavior paradigm of the structured top-down attentional modulation of prepulse inhibition with multiple path-ogenic factors related to schizophrenia to establish a new model generation,which will be of great significance in investigating both the pathogenesis and the treatment of schizophrenia.