Point mutations were introduced in exon 41 to express Ala in place of Ser1700 and Thr1704 in the alpha-1 subunit of Cav1.2. The neo cassette was removed by flp mediated recombination. The total number of Cav1.2 channels are reduced by approximately 12% in myocytes from homozygous mice compared with wild-type. (J:203057)