Disrupted Cacna1c gene expression perturbs spontaneous Ca(2+) activity causing abnormal brain development and increased anxiety

The L-type voltage-gated Ca(2+) channel gene CACNA1C is a risk gene for various psychiatric conditions, including schizophrenia and bipolar disorder. However, the cellular mechanism by which CACNA1C contributes to psychiatric disorders has not been elucidated. Here, we report that the embryonic deletion of Cacna1c in neurons destined for the cerebral cortex using an Emx1-Cre strategy disturbs spontaneous Ca(2+) activity and causes abnormal brain development and anxiety. By combining computational modeling with electrophysiological membrane potential manipulation, we found that neural network activity was driven by intrinsic spontaneous Ca(2+) activity in distinct progenitor cells expressing marginally increased levels of voltage-gated Ca(2+) channels. MRI examination of the Cacna1c knockout mouse brains revealed volumetric differences in the neocortex, hippocampus, and periaqueductal gray. These results suggest that Cacna1c acts as a molecular switch and that its disruption during embryogenesis can perturb Ca(2+) handling and neural development, which may increase susceptibility to psychiatric disease.