CACNA1D and Parkinson disease: Cav1.2 and Cav1.3 in the L-type voltage-gated Ca2+ channels are associated with PD [27] and Cav1.2 is prevalent in juvenile SNc (Substantia Nigra) DA neurons, but in senescent SNc DA neurons, Cav1.3 is preferentially used for Ca2+ inflow, allowing Ca2+ to enter through an oscillatory pathway that contributes to the membrane potential threshold, which is the basis of autonomous pacing [28].