When acetylcholine binds postsynaptic nicotinic acetylcholine receptors, each receptor causes Its own postsynaptic voltage change, which is called an end-plate potential.
The summation of the end-plate potentials represents the membrane potential.
The synaptic acetylcholine concentration influences the amplitude of end-plate potentials
Blocking presynaptic, VG Ca channels would most decrease the end-plate potential amplitude!
submitted by โsolidshake(25)
An AP is generated once the summation of charge at the axon hillock reaches a threshold voltage. Once the threshold voltage is passed, an AP is generated. However, the peak amplitude of the AP above threshold can still vary depending on the number of Na channels that are simultaneously open while the AP is present.
Thus, after the AP threshold has been reached and the AP is generated, the peak voltage attained can be reduced in amplitude if the first Na channels that opened begin to close because of a short inactivation time.