What are postsynaptic potentials IPSP and EPSP and how do th

What are postsynaptic potentials (IPSP and EPSP) and how do they trigger an action potential?

Solution

Answer;

Postsynaptic potentials are changes in the membrane potential of the postsynaptic terminal of a chemical synapse.

At excitatory synapses, neurotransmitter binding depolarizes the postsynaptic membrane. This increases a postsynaptic neuron\'s ability to generate an action potential hence it is called Excitatory postsynaptic potential (EPSP).

On the other hand, neurotransmitter binding to inhibitory synapses makes membrane more permeable to K+, and Cl- causing hyperpolarization of membrane potential. This reduces a postsynaptic neuron\'s ability to generate an action potential hence it is called inhibitory postsynaptic potential (IPSP).

In summary Postsynaptic potentials are called excitatory if they increase the likelihood of a postsynaptic action potential occurring, and inhibitory if they decrease this likelihood.