Kainate receptors activate NF-kappaB via MAP kinase in striatal neurones.

The transcription factor NF-kappaB has been implicated in the synaptic plasticity and neurotoxicity mediated by ionotropic glutamate receptors in the striatum. However, the class of glutamate receptor and the intracellular pathways involved have not been determined. Kainate, but not AMPA or NMDA, was found to activate NF-kappaB in superfused slices of rat striatum. A similar activation was produced by the calcium ionophore A23187. The NF-kappaB activation by kainate was not observed in the absence of extracellular calcium, and was blocked by the p44/p42 MAP kinase inhibitor PD98059, but not by the p38 MAP kinase inhibitor SB203580. This demonstrates that striatal kainate receptors are coupled to NF-kappaB activation via calcium influx and p44/p42 MAP kinase activation.