CHARACTERIZATION OF SENSORIMOTOR PERFORMANCE, REPRODUCTIVE AND AGGRESSIVE BEHAVIORS IN SEGMENTAL TRISOMIC-16 (TS65DN) MICE

In the present study, segmental trisomy 16 (Ts65Dn) mice, an animal mo del of Down Syndrome (DS), were examined for sensorimotor, reproductiv e, and aggression abnormalities associated with DS. The Ts65Dn mice ex hibited no sensorimotor deficits in olfactory sensitivity, visual abil ities, orientation reactions, forelimb strength, postural skills, bala nce/coordination, climbing, or locomotion compared to genetically matc hed control B6EiC3HF1 mice. In mating tests, the percentage of Ts65Dn mice displaying intromissions when paired with estrous females was sig nificantly less than that in controls. Although the percentage of Ts65 Dn mice that mounted and ejaculated with an estrous female was margina lly less than in controls, there were no significant differences on th e other measures of reproductive behavioral performance. In aggression tests, Ts65Dn males showed increased offensive aggression in a neutra l arena both when paired and among grouped males. Conversely, Ts65Dn m ice exhibited less offensive aggression against an intruder in their h ome cage than control males. In sum, these mice possess some of the ad aptive behavior abnormalities observed in DS patients; however, becaus e the Ts65Dn mice do not have any observed sensorimotor deficits that could interfere with behavioral assessments, they may serve as a usefu l model for the study of behavioral impairments associated with DS.