inhibitory postsynaptic potential
Also written as: IPSP — inhibitory postsynaptic potential
Hyperpolarizing electrical response that reduces the likelihood of action potential generation.
Full Definition
An inhibitory postsynaptic potential (IPSP) is a temporary hyperpolarization of the postsynaptic membrane potential caused by the binding of inhibitory neurotransmitters such as GABA or glycine. IPSPs move the membrane potential away from the threshold for action potential generation, thereby reducing neuronal excitability. IPSPs can counteract excitatory inputs through shunting inhibition or direct hyperpolarization. The timing and location of IPSPs relative to excitatory inputs critically determine their inhibitory effectiveness. IPSPs are essential for maintaining the excitation-inhibition balance in neural circuits.
Usage
Usage note: Commonly abbreviated as IPSP; contrast with EPSP.
In Context
- "The IPSP was mediated by GABA receptors on the postsynaptic membrane." — Pharmacology study
- "Strong IPSPs prevented the neuron from reaching firing threshold despite excitatory input." — Electrophysiology analysis