Palmitoylation analysis relied in large part on the ABE purification of palmitoyl-proteins en masse either from whole rat brain, from purified rat synaptosomes, or from cultured embryonic rat neurons. This procedure which starts with denatured protein extracts is an in vitro chemical exchange of biotin for thioester-linked acyl modifications, with the resulting biotinylated protein being affinity-purified using streptavidin-agarose. Subjecting the purified to MuDPIT mass spectral analysis identified the contingent palmitoyl-proteins. These purified palmitoyl-proteomic samples also were used to follow individual protein palmitoylation levels in drug-induced neural activity paradigms, e.g. analyzing changes following a 5-min treatment of neuronal cultures with 50 μM glutamate or the induced changes in the post-seizure brain (kainic acid-induced). For such analysis, purified palmitoyl-proteomic samples from the treated and control conditions were immunoblotted with panels of antibodies specific to individual neuronal palmitoyl-proteins; proteins with increased or decreased palmitoylation showed corresponding increased or decreased abundance levels within the purified proteomic samples. Representations within the purified samples were normalized to levels in starting, total protein extracts, eliminating potential contributions from changes in protein expression or turnover. The localizaton and function of the two Cdc42 isoforms were assessed in cultured embryonic rat hippocampal neuronal cells transfected with plasmids expressing either N-terminally EGFP-tagged versions of the two Cdc42 isoforms (wildtype and mutant forms) or for the knockdown analysis, isoform-specific siRNAs expressed from a plasmid also co-expressing a cytosolic GFP marker. Transfected cells, identified through GFP immuno-detection, were analyzed for Cdc42 localization and morphology, e.g. the number of dendritic filopodia or spines.