Equal amounts of protein (20 μg) were loaded in each lane. Antibodies against Homer 1, 2, and 3 revealed an enrichment of the Homer isoforms at the PSD fractions relative to the parent fractions. Comparison of the two isoforms of Homer 1 indicates that the long isoform, Homer 1b/c, is enriched in PSD fractions while the short isoform, Homer 1a, is not.