Sociability and preference for social novelty test. Effects of donepezil pre-treatment and 192-IgG-saporin (Sap) lesions on sociability (a) and preference for social novelty test (PSNT) (b). Although no differences among the four groups were found in the sociability test, both groups of cholinergically depleted animals (Don-Sap and Sal-Sap) failed to exhibit an overt social novelty during PSNT. Asterisks indicate comparisons between stranger 1 and empty/stranger 2 chamber behaviors in the four groups. **P < 0.01, ****P < 0.0001. Pound symbols indicate comparisons between stranger 1 chamber and stranger 2 chamber behaviors in the sham groups (Don-Sham and Sal-Sham). #P < 0.05, ##P = 0.01. 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.