Mouse Genetic Approaches to Psychiatric Disorders

Eighty percent of mammalian genes are expressed at detectable levels in the brain, and it has become a major research endeavor to elucidate the function of individual genes and gene products in behavioral traits and psychiatric disorders. Technologies, developed in the past two decades, to manipulate individual genes, have begun to allow us to ascribe them function in the neurobiological mechanisms that underlie behavior. Two approaches have been taken: a random approach to identify novel genes associated with behavioral phenotypes; and a targeted approach where candidate genes are selectively mutated or expressed in the brain and behavioral function tested. This article explores these different methodologies, and highlights the advantages and disadvantages of the techniques using examples of genes associated with human psychiatric disorders