Assessing Prepulse Inhibition of Startle in Mice

Animal models are an important tool for studying neuropsychiatric disorders. However, a major challenge for researchers working with laboratory rodents is trying to reproduce 'core' symptoms of complex human disorders such as schizophrenia. Despite this challenge, however, it is still conceivable to use animal models designed to reproduce some of the disease's 'endo-phenotypes'. One example is the prepulse inhibition (PPI) of the startle reflex. PPI is a form of startle plasticity and is characterized by a normal reduction in startle magnitude that occurs when an intense startling stimulus (or pulse) is preceded by a weaker pre-stimulus (or prepulse). The PPI paradigm is commonly used to evaluate sensorimotor gating and it has been described in numerous species including humans and rodents. Deficits in PPI have been observed in subjects with schizophrenia and other neuropsychiatric diseases, as well as in established animal models of these disorders. The PPI paradigm is therefore largely used to explore genetic and neurobiological mechanisms underlying the sensorimotor gating phenotypes found in these disorders. Thus, it is necessary to set up reliable and reproducible protocols to study PPI in mice.