Postsynaptic Potential


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Potential, Postsynaptic

 

a relatively brief oscillation of membrane potential, generally several dozen milliseconds in duration, and occasionally lasting for seconds. The oscillation results from the action of a mediator on the postsynaptic membrane of a nerve, muscle, or glandular cell. The amplitude of the postsynaptic potential varies with the quantity of the mediator released. By interacting with the specific receptors of a postsynaptic membrane, mediators increase the membrane’s permeability to certain ions, which enter or leave the cell according to an electrochemical gradient. When this leads to a decrease in the difference in potentials between the internal and external sides of a membrane (depolarization), the postsynaptic potential is excitatory.

Inhibitory postsynaptic potential is manifested by hyperpolar-ization of the cell owing to the action of the inhibitory mediator. A nerve cell usually has a large number of synaptic entrances and the incoming signals are summated algebraically. Excitatory postsynaptic potential increases and inhibitory postsynaptic potential decreases the frequency of the discharges in cells that spontaneously generate action potential. In silent cells, excitatory postsynaptic potential may cause a solitary or group discharge; the inhibitory postsynaptic potential arising at the same time may block this effect. Thus, postsynaptic potential controls the excitability of nerve cells.

L. G. MAGAZANIK

References in periodicals archive ?
Four to five trains of action potentials (1 per second) were evoked, and postsynaptic potentials (PSPs) were examined.
The amplitudes of miniature postsynaptic potentials (mPSPs) were measured over a period of 2 min.
These APs propagate to synapses and elicit excitatory postsynaptic potentials (EPSPs).
This preparation also served for identifying motor activity in the nerves by recording en passant from the nerve with a suction electrode while simultaneously intracellularly recording muscle cell postsynaptic potentials (PSPs).
The activity of some of the neurons in the nerve root correlated with muscle excitatory postsynaptic potentials (EPSPs).
In Hermissenda, impulses of the caudal hair cells (located on the tail half of the cyst on the dorsoventral equator) cause a cessation of excitatory postsynaptic potentials (EPSPs) received by ipsilateral type B cells.
Under general anesthesia, action potentials could not be elicited, although underlying postsynaptic potentials were still apparent.
Impulses of specific small-cell axons can be correlated with excitatory postsynaptic potentials (EPSPs) recorded intracellularly from large-cell somata (Fig.
Stimulation of the extrinsic regulator nerve during intracellular recording from large CG neuronal somata produces postsynaptic potentials following, one for one, the stimuli to the axon, and repetitive stimulation causes the expected slowing of bursting (Fig.
In another study, GABA hyperpolarized the sternal arterial valve and masked inhibitory postsynaptic potentials (IPSPs) arising from inhibitory nerve stimulation (Kuramoto et al.
Brief perturbations, which were simulated postsynaptic potentials (PSPs), could switch the activity of R15 between different modes.