AN ASSESSMENT OF BEHAVIORAL AGING IN THE MONGOLIAN GERBIL

Male Mongolian gerbils (Meriones unguiculatus) 14-54 months old (n = 7 7) were evaluated in a battery of psychomotor (open field, locomotor, and runwheel activity, rotorod performance) and learning (one-way acti ve avoidance in a straight runway and in 14-unit T-maze performance) t ests. Body weight and seizure activity were also monitored. According to Linear regression analysis, runwheel activity decreased with age; a nd the number of errors in the 14-unit T-maze increased as a function of age (ps < 0.05). None of the other behavioral measures or body weig ht were significantly correlated with age. This gerbil strain (Tumbleb rook Farms; West Brookfield, MA) tended to be very prone to seizures w ith 64% of the gerbils experiencing at least one seizure while being t ested. Seizures tended to occur when the gerbil was exposed to a novel situation (e.g., initial weighing, placement on the rotorod). An age- related decline in some aspects of psychomotor and learning performanc e was observed, suggesting the gerbil as an additional mammalian model of aging. The high incidence of seizure activity presented a complica ting and confounding variable to the interpretation of the results of the behavioral tests used in the present study. Interventions to contr ol seizure activity (e.g., systematic, controlled breeding; adaptation to apparati) in this model will likely increase its viability as a ma mmalian model of aging. Published by Elsevier Science he.