Pilocarpine, physostigmine, and memantine stimulation of Akt phosphorylation. Mice were treated with (A) pilocarpine (30 mg/kg; 5, 15, 30, 60, 90 and 120 min), (B) physostigmine (0.1, 0.2, 0.4 and 0.8 mg/kg; 15 min), or (C) memantine (50 mg/kg; 2 h), physostigmine (0.4 mg/kg; 15 min), or both drugs (physostigmine was given 105 min after memantine, for 15 min). Protein extracts from the hippocampus, cerebral cortex, and striatum were immunoblotted with antibodies for phospho-Thr308-Akt, phospho-Ser473-Akt, and total Akt. Quantitative values were obtained by densitometric scans of immunoblots (means ± S.E.M.; n=4). No statistically significant differences (p > 0.05) were observed comparing the results from treatment with physostigmine alone to those following treatment with memantine plus physostigmine.