Experimental Stroke Alters Depressive-like Behavior in Mice.

Abstract

P68 Depression is a common consequence of stroke in humans and is associated with an increase in cognitive deficits and impaired functional recovery. However, the etiology of post-stroke depression remains unknown. The purpose of the present study was to determine if focal cerebral ischemia in mice induces changes in a rodent behavioral model of depression that can be reversed through treatment with fluoxetine,a selective serotonin reuptake inhibitor. Increased time spent immobile versus actively swimming in the Porsolt Swim Test is a commonly used index of depressive-like behavior in rodents. Male C57/BL6 mice were subjected to a 2 min forced swim one day prior to 60 min middle cerebral artery occlusion (MCAO; using a 6.0 nylon filament) or sham-surgery. Beginning 7 days after surgery, the animals were injected IP daily with fluoxetine or the vehicle. One week later, the animals were subjected to a second swim test and the amount of time spent actively swimming versus immobile was recorded. Experimental stroke increased frequency and time spent immobile during the Porsolt Swim Test. Furthermore, chronic treatment of MCAO animals with 20 mg/kg of fluoxetine restored swimming behavior to SHAM levels (see table). These data suggest that post-ischemic affective disorders can be modeled in animals and are modulated by antidepressants.