Inhibitory neurotransmitters reduce the chance of postsynaptic firing by hyperpolarizing membranes or counteracting excitatory inputs, linking cellular mechanisms to rapid communication in nervous systems.
Inhibitory neurotransmitters make a postsynaptic neuron less likely to reach action-potential threshold.
They may open chloride channels, increase potassium efflux or reduce excitatory channel activity. The resulting hyperpolarization or shunting inhibition opposes excitatory inputs. Inhibition is relational: the same transmitter can have different effects if receptor types differ, and the receiving circuit determines the outcome.
Identify inhibition by checking:
Opening chloride channels can stabilize the membrane near its resting potential and reduce the effect of a simultaneous EPSP.
Inhibition is not always a large negative voltage; increased conductance can also shunt excitatory current.