Rationale: Authors study the localization of Abi-1 in rat hippocampal cultures and rat brain using a monoclonal antibody against Abi-1. Immunoelectron microscopy revealed Abi-1 at postsynaptic densities. In line with this, immunostaining of Abi-1 showed colocalization of the protein with Shank3, a postsynaptic excitatory marker, while coimmunostaining with the presynaptic marker bassoon revealed a juxtaposed pattern, in agreement with the postsynaptic localization of Abi-1. Subcellular fractionation revealed enrichment of Abi-1 in PSD fractions. 14/3/2017 Pim - Abi1 shown to interact directly with Shank3 but not with Shank1 (Fig.1). Shank3 is a typical PSD protein.. Experimental description: From M&M: - Cell culture experiments of rat hippocampal primary neurons (embryonic day-18-21; E18-21). - For isolation of subcellular protein factions and Western Blot analysis tissue from adult rats was homogenized.