Previous chapters of this book have highlighted technical advances made in recording ensembles of neurons in primates and rats. These advances have created a novel window through which to study brain function, allowing us to interpret an ever-growing body of data describing how the normal brain operates. On the other hand, these techniques have only provided a limited picture of how alterations in brain function generate behavioral pathology, requiring new recording techniques to be manufactured. In this chapter, we describe a novel method for extending previously described electrophysiological recording techniques for use in transgenic mice. This fusion of genetic and neuroscience technologies provides a promising tool for elucidating how changes in gene expression result in the behavioral alterations characteristic of central nervous system (CNS) disease.