kainatereseptorit

Kainatereseptorit, known in English as kainate receptors, are a subfamily of ionotropic glutamate receptors (iGluRs) that mediate excitatory neurotransmission in the central nervous system. They form tetrameric ligand-gated ion channels composed of subunits GluK1–GluK5, encoded by the GRIK1–GRIK5 genes. Subunits can assemble as homo- or heteromeric complexes, yielding receptors with distinct biophysical and pharmacological properties.

Kainate receptors are located at both postsynaptic and presynaptic sites throughout the brain, notably in the hippocampus and cortex. Postsynaptic receptors contribute to fast excitatory currents, while presynaptic receptors regulate the release of neurotransmitters, including glutamate and, in some circuits, GABA, thereby modulating synaptic transmission and network activity. The channel is permeable to Na+ and K+, and Ca2+ permeability depends on subunit composition, influencing calcium signaling and plasticity. Compared with AMPA receptors, kainate receptors often show slower desensitization, contributing to their distinct role in synaptic signaling.

Activation by glutamate or kainic acid elicits excitatory currents; researchers employ selective agonists and antagonists to study subunit-specific actions. Kainate receptors contribute to synaptic plasticity in certain circuits and are implicated in physiological processes such as learning and memory, as well as pathological states including epilepsy and neurotoxicity.

In Finnish sources, these receptors are referred to as kainatereseptorit, paralleling the English term. They are part of the broader iGluR family, alongside AMPA and NMDA receptors, and remain a focus of ongoing neuroscience and pharmacology research.