The T-type Ca2+ Channel Cav3.2 Regulates Differentiation of Neural Progenitor Cells during Cortical Development via Caspase-3

Abstract Here we report that the low-voltage-dependent T-type calcium (Ca 2+ ) channel Ca v 3.2, encoded by the CACNA1H gene, regulates neuronal differentiation during early embryonic brain development through activating caspase-3. At the onset of neuronal differentiation, neural progenitor cells exhibited spontaneous Ca 2+ activity. This activity strongly correlated with the upregulation of CACNA1H mRNA. Cells exhibiting robust spontaneous Ca 2+ signaling had increased caspase-3 activity unrelated to apoptosis. Inhibition of Ca v 3.2 by drugs or viral CACNA1H knock down resulted in decreased caspase-3 activity followed by suppressed neurogenesis. In contrast, when CACNA1H was overexpressed, increased neurogenesis was detected. Cortical slices from Cacna1h knockout mice showed decreased spontaneous Ca 2+ activity, a significantly lower protein level of cleaved caspase-3, and microanatomical abnormalities in the subventricular/ventricular and cortical plate zones when compared to their respective embryonic controls. In summary, we demonstrate a novel relationship between Ca v 3.2 and caspase-3 signaling that affects neurogenesis in the developing brain.