Fast transmission

The action of neurotransmitters on ligand-gated ion channels is fast. The modifications in membrane potential take place within a millisecond or so and return to the resting potential in tens of milliseconds. This is rapid neurotransmission. The binding of transmitter to the ligandgated ion channels raises the permeability of the postsynaptic membrane to whatever ions the channel conducts. This modifies the potential of the postsynaptic membrane, producing a postsynaptic potential. These potentials are usually just a few millivolts in amplitude. They spread passively over the plasma membrane of the nerve cell, withdrawing in size as they move away from the postsynaptic membrane, and with time as their generation. The Postsynaptic potentials come in two flavors, inhibitory and excitatory.