Calcium (Ca2+) is an important messenger that plays critical roles in cellular processes. Particularly, Ca2+ plays crucial roles in many processes in neurons including synaptic transmission. Recently, it was reported that mitochondria-associated endoplasmic reticulum (ER) membrane (MAM) dynamically transfers Ca2+ from the ER to mitochondria. However, it is very difficult to measure Ca2+ in MAM in living neurons. Using newly developed Ca2+ indicators in MAM, we will investigate the Ca2+ dynamics in MAM in neurodegenerative diseases. This joint work will reveal the Ca2+ dynamics in MAM in neurodegenerative diseases, which will offer new insights in Ca2+ dynamics in brain disorders and provide new therapeutic targets for brain disorders.