Before revision:  While calcium influx through NMDA-R plays a critical role in synaptic plasticity, indirect experimental evidence also exists demonstrating actions of NMDAR-mediated calcium influx on neuronal excitability through the activation of calcium-activated potassium channels.
After revision:  While calcium influx through NMDA-R plays a critical role in synaptic plasticity, experimental evidence indicates that NMDAR-mediated calcium influx on neuronal excitability through the activation of calcium-activated potassium channels.