Inhibitory postsynaptic potentials (IPSPs)

Definition

Inhibitory postsynaptic potentials (IPSPs) are changes in the membrane potential of a neuron that make it less likely to generate an action potential. They usually result from the influx of negatively charged ions or the efflux of positively charged ions through postsynaptic membrane channels.

5 Must Know Facts For Your Next Test

1. IPSPs typically involve neurotransmitters such as GABA or glycine binding to their receptors.
2. The main effect of IPSPs is hyperpolarization of the postsynaptic membrane, moving it further from the threshold for action potential generation.
3. Chloride (Cl-) and potassium (K+) ions are commonly involved in generating IPSPs.
4. IPSPs can summate with excitatory postsynaptic potentials (EPSPs) to influence whether a neuron will fire an action potential.
5. The balance between EPSPs and IPSPs determines the overall excitability of a neuron.

Review Questions

Related terms

Excitatory Postsynaptic Potentials (EPSPs): Changes in membrane potential that make a neuron more likely to fire an action potential.

Action Potential: A rapid rise and fall in membrane potential that propagates along a neuron's axon.

Neurotransmitter: Chemical messengers released by neurons to communicate with other neurons or cells.