Excitatory post synaptic potential is due to
EPSP (Excitatory post synaptic potential) -
1. Definition: the increase in voltage above the normal resting potential — that is to a less negative value — is called
EPSP because if this potential rises high enough, it will elicit on action potential in the neuron, thus exciting it.
    EPSP is due to depolarization.
2. Production à rapid influx of Na+ to the interior neutralised part of the negativity of RMP à RMP ­ed from - 65 to      - 45 my à EPSP à excite the neuron.
K+ influx
Na+ efflux
Na+ influx
Ca++ influx