Ectopic collections of neurons in upper layers of neocortex are hypothesized to cause aberrations in information processing in both humans and mouse models of human learning deficits. These ectopic collections are believed to exert their effects by disrupting the appropriate development of neuronal function in both thalamic and neocortical circuits. The experiments described in this proposal represent the first cellular neurophysiological analysis of the effects of neocortical ectopias on neurons in cortex and thalamus. These studies will be conducted by applying whole-cell patch clamp techniques to neurons in living brain slices obtained from genetic mouse models of cortical ectopias, BXSB and NZB mice, and from a surgically induced model of cortical ectopias. The goal of these experiments will be to identify and characterize aberrations in synaptic and cellular physiology associated with neocortical ectopias. This information may lend insight into the cellular mechanisms underlying learning deficits.