distribution patterns of RYR1/2 and RYR3, it appears the first two mechanisms cannot account for the inhibition because a close proximity between RYR1/2 and RYR3 and between VDCC and RYR3 is required for these mechanisms to operate. If RYR1/2 and RYR3 share the same Ca2+ stores, the third mechanism could be possible. However, the authors did not observe any difference in Ca2+ spark amplitude between wild-type and RYR3−/− cells. Therefore, our results on the distribution of the three types of RYRs raise other possibilities for the inhibition that warrant further investigation.
