Question

Identify and explain the role of EPSPs and IPSPs in determining whether or not a postsynaptic neuron achieves an action potential.

Answer 1

Ans . An EPSP( excitatory postsynaptic potential) is a postsynaptic potential that makes the postsynaptic neuron more likely to fire an action potential. This temporary depolarization of postsynaptic membrane potential , caused by the flow of positively charged ions into the postsynaptic cell, is a result of opening ligand-gated ion channels.

These are the opposite of IPSP( inhibitory postsynaptic potential) , which usually results from the flow of negative ions into the cell or positive ions out of the cell.

The EPSP increases the probability that the postsynaptic neuron will produce an action potential, defining this synapse as excitatory.

IPSP tend to keep the membrane potential of the postsynaptic neuron below threshold for firing an action potential. IPSPs are important because they can counteract, or cancel out, the excitatory effect of EPSPs.