In particular, the functional effects of the VSM-affecting R192Q mutation have been studied in a knock-in mouse model: electrophysiological recordings from cerebellar granule cells of this mouse showed an increase in Cav2.1 current density, a hyperpolarizing shift in the voltage-dependence of current activation, an increase in calcitonin gene-related peptide (CGRP) release and increased susceptibility to cortical spreading depression (Tottene et al., 2009), a mechanism that is believed to cause the migraine-preceding aura (Lauritzen, 1994). Here, CACNA1A is linked to migraine disorder.