Postsynaptískrar

Postsynaptískrar are the components of a chemical synapse located on the receiving side of neurotransmission. They encompass the membrane of the postsynaptic neuron or muscle cell, its receptors, ion channels, and the signaling machinery that converts a chemical signal into an electrical or biochemical response. In central nervous system circuits, these elements are typically found on dendritic membranes or the soma, while at the neuromuscular junction they reside on the muscle cell membrane.

The primary function of postsynaptískrar is to detect neurotransmitters released by the presynaptic terminal and to translate that chemical signal into a postsynaptic potential. Binding of neurotransmitters to receptors produces either excitatory postsynaptic potentials (EPSPs), generally through cation channels that allow Na+ and Ca2+ influx, or inhibitory postsynaptic potentials (IPSPs), often via Cl− or K+ channels. Receptors are broadly categorized as ionotropic (ligand-gated ion channels that generate fast responses) and metabotropic (GPCRs that trigger slower, longer-lasting signaling cascades).

Common receptor types include glutamate receptors (AMPA, NMDA, kainate) for excitation and GABA_A (and glycine) receptors for inhibition; acetylcholine receptors are prominent at the neuromuscular junction. The postsynaptic density (PSD) is a protein-rich region beneath the membrane that organizes receptors and signaling proteins, influencing receptor localization and synaptic strength.

Plasticity at the postsynapticiliarye—through receptor trafficking, phosphorylation, and structural changes such as dendritic spine remodeling—underpins learning and memory. Dysfunctions in postsynaptic signaling are linked to neurological and psychiatric disorders.