[Jazzified]

Hello.  I was given an assignment and for the most part completed it.  However, I am stuck on the following question and would like to know if anybody is able to help me answer it.  Thanks in advance!

Presenilin 1 and presenilin 2 are described as Ca2+ leak channels in the endoplasmic reticulum.  Normall, activation of receptors that use CA2+ as second messengers causes release of a limited amount of CA2+ from the endoplasmic reticulum.  What is the result of activating receptors in cells that have non-functional presenilins?  Why might that occur when presenilins are mutated?