GRIA2 and infection: To determine whether infection of spinal motoneurons with the RCASBP(B)-RFP-GluA2 siRNA construct leads to a significant increase in the Ca2+ permeability of AMPA receptors in E11 motoneurons, we recorded the kainate-generated currents in a Na+-free, high Ca2+ extracellular solution as previously reported [12].