Choline acetyltransferase immunoblot analysis. Representative choline acetyltransferase (ChAT) immunoblots of hippocampal (hp) and neocortical (cx) total protein extracts and densitometric quantification of changes in gray values expressed as mean ± SD. The relative fold change in the levels of ChAT protein was normalized with respect to the level of actin, which was used as a loading control. Statistical differences were observed between the sham and 192-IgG-saporin (Sap)-lesioned animals (n = 3/group). *P < 0.05 by t-test. Don-Sap, donepezil-treated Sap-lesioned rats; Don-Sham, donepezil-treated sham-lesioned rats; Sal-Sap, saline-treated Sap-lesioned rats; Sal-Sham, saline-treated sham-lesioned rats.