(D) Representative time trace showing the normalized change in Fluo8 fluorescence on NMDA treatment in the presence or absence of extracellular Ca2+ and D-AP5. Values in all other groups were normalized to the unsimulated condition for the corresponding experiment and all the data points are represented as a fraction of the initial time point. Ionomycin treatment in the presence of 10mM Ca2+ was used to calculate fluorescence maximum for a particular cell. 