The rat middle cerebral artery (MCA) occlusion model with an intralumi
nal filament is well characterized with a two hour period of occlusion
in widespread use. The recent availability of transgenic animals has
led to an interest in adapting the MCA model in the mouse. To date the
model has not been well characterized in the mouse. We performed the
present study to compare different durations of MCA occlusion and to v
alidate new functional assessments in this model. The MCA occlusion mo
del (5-0 filament) was used. Swiss-Webster mice, 24-44 g, were randoml
y assigned to four groups: one hour of occlusion; two hours of occlusi
on; three hours of occlusion; or permanent occlusion. At 48 hours post
-ischemia, the animals were rated on three neurologic function scales,
and then the brains were removed for lesion size determination. Overa
ll, there was a significant difference in lesion volume (p < 0.001) be
tween the groups. In the permanent group of mice, the average lesion v
olume was 78.41 +/- 17.47 mm (n = 12); two and three hours of ischemia
produced 51.29 +/- 29.82 mm(3) (n = 11) and 54.85 mm(3) (n = 13), res
pectively, significantly different than the one hour group 14.84 +/- 3
1.34 mm(3) (n = 11). All three functional scoring systems found signif
icant overall differences between the four groups with our detailed Ge
neral and Focal scores producing more robust between group treatment d
ifferences and showing correlation coefficients of r = 0.766 and r = 0
.788, respectively to infarct volume. The MCA filament occlusion model
can be successfully adapted in the mouse with either two or three hou
r occlusions producing reliable infarcts. New functional scoring syste
ms unique to the mouse appear to add additional information.