AMPA/KA receptor induced AP-1 DNA binding activity in cultured Bergmann glia cells.

The effect of L-glutamate (L-Glu) and its structural analogs kainate (KA) and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) on the DNA binding activity of the activator protein 1 (AP-1) family of transcription factors was examined in cultured chick cerebellar Bergmann glia cells. These agonists evoked a dose- and time-dependent increase in AP-1 DNA binding activity and their responses were blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). The increase in DNA binding is probably mediated by an AMPA/low affinity KA subtype of L-Glu receptor. The synaptic localization of these receptors, their ion channel properties and a stimulus-transcription coupling further strengthen the putative role of glia cells in the modulation of synaptic efficacy and plasticity.