Correlation between motor impairment and infarct volume after permanent and transient middle cerebral artery occlusion in the rat.
OBJECTIVE
There have been a number of recent reports describing the relationship between ischemic damage and various behavioral and functional measures, although there have been few studies that have demonstrated a direct correlation between functional impairment and lesion volume. The purpose of the present study was to assess functional outcome by measurement of motor impairment and to determine whether this correlated to a range of infarct volumes induced by varying the duration of focal ischemic insult in the rat.


METHODS
Male Sprague Dawley rats were subjected to 0, 30, 60, of 120 minutes or permanent middle cerebral artery (MCA) occlusion by the intraluminal filament technique. Motor impairment was assessed by the accelerating rota-rod and grid-walking tests, and the brains were perfusion-fixed for histological determination of infarct volume and brain swelling 24 hours after MCA occlusion.


RESULTS
Marked impairment in performance of both motor tests was recorded in the 60-minute, 120-minute, and the permanent MCA occlusion groups when compared with sham-operated rats. There were significant correlations between regional infarct volume, brain swelling, and all behavioral measurements (all r2 > .5, P < .001).


CONCLUSIONS
The rota-rod and grid-walking tests of motor performance provide quantitative, objective, and reproducible measures of functional impairment of rats following an ischemic insult. These impairments correlate directly with infarct volume and provide information integral to future studies evaluating the effects of potential neuroprotective agents.
Rogers
D C
DC
Neurosciences Research, SmithKline Beecham Pharmaceuticals, Harlow, Essex, United Kingdom. Derek_C_Rogers@sbphrd.com
Campbell
C A
CA
Stretton
J L
JL
Mackay
K B
KB
D000208:Acute Disease; D000818:Animals; D001157:Arterial Occlusive Diseases / Q000473:pathology* / Q000503:physiopathology* / Q000523:psychology; D001522:Behavior, Animal / Q000502:physiology; D001921:Brain / Q000473:pathology; D001929:Brain Edema / Q000209:etiology; D002536:Cerebral Arteries; D002544:Cerebral Infarction / Q000473:pathology* / Q000503:physiopathology* / Q000523:psychology; D002908:Chronic Disease; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors