When the neuron receives stimulus by
the binding neurotransmitters to
specific receptors channels open
and the of the plasma
membrane the post synaptic region
altered. Sodium ions then into the
cell causing (less negative) of
the potential.If this
reduction of membrane potential
reaches a called the excitation
threshold, threshold potential,about
–50 mV, action potential is
generated, .e., the depolarization
intensifies until its maximum
level and depolarization current is
transmitted the remaining length
of neuronal membrane.

If the threshold is reached
voltage-dependent channels in
the membrane allowing more
sodium ions enter the cell in of
the concentration gradient an
approximate –35 mV of positive
polarization of membrane is
achieved. The -dependent
sodium channels then close more
voltage-dependent potassium channels
. Potassium ions then exit cell
in favour of concentration gradient
and the difference of the
membrane , a process called
repolarization.

action potential triggers the
electrical phenomenon in neighboring
of the plasma membrane
the impulse is thus from the
dendrites to terminal region of the
.