Kainate receptors containing the GluK1 subunit have an impact on excitatory and inhibitory neurotransmission in brain regions, such as the amygdala and hippocampus, which are relevant to
seizures and
epilepsy. Here we used 2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl)
propanoic acid (ATPA), a potent and selective agonist of
kainate receptors that include the GluK1 subunit, in conjunction with mice deficient in GluK1 and
GluK2 kainate receptor subunits to assess the role of GluK1
kainate receptors in provoking
seizures and in kindling epileptogenesis. We found that systemic ATPA, acting specifically via GluK1
kainate receptors, causes locomotor arrest and forelimb extension (a unique behavioral characteristic of GluK1 activation) and induces myoclonic behavioral
seizures and electrographic seizure discharges in the BLA and hippocampus. In contrast, the proconvulsant activity of systemic
AMPA,
kainate, and
pentylenetetrazol is not mediated by GluK1
kainate receptors, and deletion of these receptors does not elevate the threshold for
seizures in the 6 Hz model. ATPA also specifically activates epileptiform discharges in BLA slices in vitro via GluK1
kainate receptors. Olfactory bulb kindling developed similarly in wild-type, GluK1, and GluK2 knock-out mice, demonstrating that GluK1
kainate receptors are not required for epileptogenesis or seizure expression in this model. We conclude that selective activation of
kainate receptors containing the GluK1 subunit can trigger
seizures, but these receptors are not necessary for seizure generation in models commonly used to identify therapeutic agents for the treatment of
epilepsy.