postsynaptyczny

Postsynaptyczny is an adjective used in Polish to describe elements related to the postsynaptic side of a chemical synapse. The postsynaptic component is the membrane and associated structures of the cell that receive neurotransmitter signals, most commonly a neuron but also muscle cells at the neuromuscular junction or other target cells.

In chemical synaptic transmission, neurotransmitters released from the presynaptic terminal cross the synaptic cleft and bind to receptors on the postsynaptic membrane. This binding generates postsynaptic potentials, which are graded changes in membrane potential. Excitatory postsynaptic potentials (EPSPs) depolarize the cell and increase the likelihood of firing an action potential, while inhibitory postsynaptic potentials (IPSPs) hyperpolarize or stabilize the membrane and reduce excitability. The integration of multiple EPSPs and IPSPs at the soma or axon hillock determines whether the neuron will produce an action potential.

Postsynaptic receptors come in two main families: ionotropic receptors, which are ligand-gated ion channels producing rapid, direct changes in membrane potential; and metabotropic receptors, which are G protein–coupled receptors that produce slower, longer-lasting effects through second messenger pathways. The postsynaptic density, a protein-rich region beneath the postsynaptic membrane, anchors receptors and signaling machinery, contributing to receptor localization and synaptic strength.

Plasticity at the postsynaptic site, including changes in receptor number, localization, and signaling efficacy, underlies learning and memory through mechanisms such as long-term potentiation and long-term depression. Dysfunctions in postsynaptic signaling are implicated in several neurological and psychiatric disorders.