Evaluation of Social Deficits in Initial Stages of Alzheimer’s Disease using AlCl3 Mouse Model

Abstract

Alzheimer’s disease is a progressive neurodegenerative disease of the brain that ultimately leads to dementia. It is characterized by distinct behavioral and cognitive deficits that differ from those observed in normal aging. The objective of the study was to investigate the effects of intensive treatment of AlCl3 on cognitive abilities in Alzheimer’s disease in particular to the effect on social interactions, anxiety responses, aggressive behavior and social dominance. Chemically induced Alzheimer’s disease mouse model was developed by treating 11 months old BALB/c mice with AlCl3 intraperitoneally for a period of 14 days. On day 14, AlCl3 treated mice were subjected to a battery of tests including elevated plus maze, social novelty and tube dominance test to assess cognitive abilities and behavioral responses. Elevated plus maze was used to assess exploratory behavior and anxiety responses. Time spent in closed arms by AlCl3 treated mice was significantly higher (p=0.001) as compared to control mice indicating increase in anxiety response. The number of entries into open arms was significantly (p=0.0005) lower in AlCl3 treated mice compared to control, demonstrating reduced exploratory activity. Assessment of sociability and interest in social novelty was done by social novelty test. A significant deficit in sociability was observed in AlCl3 treated mice (p=0.0003). Tube dominance test was performed to assess the aggressive tendencies and dominant/submissive behavior in AlCl3 treated mice, however a significant difference in aggressive tendencies of control and AlCl3 treated mice was not observed (p>0.05). Results indicated that AlCl3 induced mouse model of Alzheimer’s disease depicts cognitive impairment like the development of AD in the initial stages and its relation to disease progression. Understanding the behavioral and cognitive manifestations that occur in this model may aid in the early diagnosis and appropriate treatment of the disease.