Acute brain slices allow electrophysiological and imaging techniques to be applied in vitro to the study of neuronal ion channels, synaptic plasticity, and whole-cell function in juvenile and adult tissue. Ion channel recordings from small dendritic branches and axons in brain slices have demonstrated considerable functional differences in ion channel function within subregions of single cells. These findings have greatly increased our understanding of neuronal computation. This chapter presents methods for obtaining high-quality brain slices developed to aid visualization of small neuronal structures using differential interference contrast microscopy.