Question

Describe what causes excitatory and inhibitory post-synaptic potentials, and how each affect a post-synaptic neuron.

Answer 1

what causes excitatory and inhibitory post-synaptic potentials?

Excitatory post-synaptic potentials:

This is a temporary depolarization of the post-synaptic membrane caused by the flow of positively charged ions into the postsynaptic cell resulting from ligand-sensitive openings of the channels.

The excitatory postsynaptic potential is received when an excitatory presynaptic cell, which is connected to the dendrite, fires an action potential.

The excitatory postsynaptic potential increases the neurons membrane potential.

Inhibitory post-synaptic potentials:

It is a temporary hyperpolarisation of the post-synaptic membrane caused by the flow of negative ions into the postsynaptic cell.

The Inhibitory postsynaptic potentials are received when an inhibitory presynaptic cell, which is connected to the dendrite, fires an action potential.

The inhibitory postsynaptic potentials decrease the neurons membrane potentials.

How excitatory post-synaptic potentials affect a post-synaptic neuron.

The excitatory postsynaptic potential is a postsynaptic potential that makes the postsynaptic neuron more likely to fire an action potential.

When multiple excitatory post-synaptic potentials (EPSPs) occurs on a single patch of the postsynaptic membrane, their combined effect is the sum of each EPSP. Larger EPSPs result in greater depolarization of the membrane and thus increase the probability that the postsynaptic cell can reach the threshold for firing an action potential.

How Inhibitory post-synaptic potentials affect a post-synaptic neuron.

The inhibitory postsynaptic potential is a kind of synaptic potential, which makes a postsynaptic neuron less likely to produce an action potential.

Due to an inhibitory postsynaptic potential (IPSPs), depolarization may also happen, if the reverse potential lies between the resting threshold and the threshold for the action potential.