Transient focal cerebral ischemia induces sensorimotor deficits in mice

Rodents have been extensively used for experimental stroke research with rat and gerbil the preferred species. With the advent of transgenesis and gene targeting the number of mutant mouse strains is rapidly increasing. Thus, mouse models of stroke will be of great importance in the analysis of genetic factors affecting stroke. Demonstrating long-term functional recovery is of paramount importance for the pharmacological evaluation of putative stroke therapies. In the present paper we induce mild focal cerebral ischemia by tandem occlusion of the right middle cerebral artery (MCA), via craniotomy, together with the common carotid artery for 45 min in C57BL/6 strain of mice. The effects of ischemia were evaluated acutely by MRI and long-term (> 3 weeks) sensorimotor functional deficits were analyzed using a number of behavioral paradigms including the rotorod, wire hang, horizontal surface approach, eye-closure reflex, and T-maze tests. Although the induced brain damage is mild we show that it leads to clearly detectable and significant sensorimotor defects associated with fine motor coordination, balance, and postural and sensory reflexes. We conclude that the applied behavioral tests will be useful in the analysis of stroke in mutant mice.