= Kainate receptor
A \b[kainate receptor] is an <ionotropic receptor> activated by the <neurotransmitter> <glutamate>. Activation opens an <ion channel>, coupling chemical recognition to an electrical response. The family is named after <kainic acid>, an experimental agonist. <Kainate receptors> and <AMPA receptors> are distinct receptor families even though some experimental agonists can activate both, making pharmacological responses alone difficult to interpret.<Altered synaptic physiology and reduced susceptibility to kainate-induced seizures in GluR6-deficient mice by C. Mulle and others>[Abstract: ionotropic receptor classes and difficulty separating kainate from AMPA responses.]{ref}
A genetic experiment helped isolate the kainate component. <C. Mulle> and colleagues generated mice lacking the subunit then called GluR6. Neurons in the hippocampal CA3 region became much less sensitive to <kainic acid>; a postsynaptic kainate current evoked by a train of mossy-fibre stimulation was absent in the mutants. This linked a molecular subunit to a synaptically evoked response, rather than merely to a response produced by bathing tissue in an agonist.<Altered synaptic physiology and reduced susceptibility to kainate-induced seizures in GluR6-deficient mice by C. Mulle and others>[Nature392,601–605(1998), abstract: deletion, CA3 responses and mossy-fibre stimulation.]{ref} The subunit's current name is <GluK2>.https://www.ncbi.nlm.nih.gov/mesh/2106638[NLM GluK2 nomenclature record, entry terms include GluR6]{ref}
For example, a current produced by an agonist that also activates <AMPA receptors> cannot be assigned wholly to <kainate receptors>. Comparing selective perturbations with synaptic stimulation supplies stronger evidence for the receptor responsible. In another experimental setting, paired recordings in ground-squirrel retina showed that <AMPA receptors> and <kainate receptors> could route cone signals into <OFF retinal bipolar cells> with different temporal filtering properties.<Bipolar cells use kainate and AMPA receptors to filter visual information into separate channels by S. H. DeVries>[Abstract and Results: paired cone/bipolar recordings, pharmacology and distinct temporal filtering.]{ref}
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