What is the Difference Between EPSP and IPSP?

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The main difference between excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs) lies in their effects on the postsynaptic neuron's membrane potential and their influence on the likelihood of an action potential being generated.

EPSPs:

  • EPSPs are excitatory, meaning they increase the likelihood of a postsynaptic action potential occurring.
  • They cause a temporary depolarization of the postsynaptic membrane, making the membrane potential more positive.
  • EPSPs are typically generated by the release of excitatory neurotransmitters such as glutamate, which bind to receptors in the postsynaptic membrane.

IPSPs:

  • IPSPs are inhibitory, meaning they decrease the likelihood of a postsynaptic action potential occurring.
  • They cause a temporary hyperpolarization of the postsynaptic membrane, making the membrane potential more negative.
  • IPSPs are typically generated by the release of inhibitory neurotransmitters such as glycine and gamma-aminobutyric acid (GABA), which bind to receptors in the postsynaptic membrane.

In summary, EPSPs and IPSPs are both types of postsynaptic potentials that influence the membrane potential of a postsynaptic neuron. EPSPs promote the generation of action potentials by depolarizing the membrane potential, while IPSPs inhibit the generation of action potentials by hyperpolarizing the membrane potential.

Comparative Table: EPSP vs IPSP

EPSP (Excitatory Post-Synaptic Potential) and IPSP (Inhibitory Post-Synaptic Potential) are two types of post-synaptic potentials that occur in neurons. Here is a table highlighting the differences between them:

Feature EPSP IPSP
Definition EPSP is an electrical charge that occurs within the post-synaptic membrane of a neuron, inducing the generation of an action potential. IPSP is an electric charge on the post-synaptic membrane that inhibits the generation of an action potential.
Direction EPSP creates an excitable state at the post-synaptic membrane, making it more likely to fire an action potential. IPSP creates an unexcitable state at the post-synaptic membrane, making it less likely to fire an action potential.
Ion Flow EPSP is caused by the flow of positively-charged ions into the postsynaptic nerve. IPSP is caused by the flow of negatively-charged ions into the postsynaptic nerve.
Neurotransmitters EPSP is mediated by excitatory neurotransmitters such as glutamate. IPSP is mediated by inhibitory neurotransmitters such as Glycine and Gamma-Amino Butyric Acid (GABA).
Reversal Potential An EPSP has a reversal potential more positive than the action potential threshold. An IPSP has a reversal potential more negative than the action potential threshold.

In summary, EPSP facilitates the firing of an action potential on the postsynaptic membrane, while IPSP inhibits the generation of an action potential.