The rabbit anti-GluR1 subunit was purchased from Chemicon (now Millipore, Temecula, CA, cat. no. AB1504). The antibody is directed against the carboxy-terminus of the rat GluR1 subunit, corresponding to the amino acid sequence SHSSGMPLGATGL, and was generated by immunizing rabbits. The antibody has been shown to be compatible with the glutaraldehyde fixation condition required for ultrastructural preservation. Specificity of this antibody has been demonstrated previously by Western blot (manufacturer’s data sheet and Petralia and Wenthold, 1992; Wenthold et al., 1992), which shows that this antibody recognizes a single band corresponding to the molecular weight, ~108 kDa, of the GluR1 subunit and neither the GluR2/3 nor GluR4 subunits of AMPARs expressed by COS-7 cells transfected with the respective GluR-subunit cDNA.
