Activation of the NMDA receptor increases intracellular calcium, which in turn acts as a second messenger for a variety of signaling pathways.
a) Activation of the NMDA receptor decreases intracellular calcium
b) Activation of the NMDA receptor has no effect on intracellular calcium
c) Activation of the NMDA receptor decreases intracellular sodium
d) Activation of the NMDA receptor increases intracellular potassium
