A comparison of different models of stroke on behaviour and brain morphology.
We compared the effects of three models of permanent ischemia, as well as cortical aspiration, on behaviour and brain morphology. Rats received a stroke either by devascularization or by two different procedures of medial cerebral artery occlusion (MCAO; small vs. large). Animals were trained in a reaching task, forepaw asymmetry, forepaw inhibition, sunflower seed task and tongue extension. Behaviour was assessed 1 week after the lesion and at 2-week intervals for a total of 9 weeks. One week after the surgery all animals were severely impaired on all tasks and although they improved over time they only reached preoperative base lines on tongue extension. Animals with small MCAOs performed better in reaching and sunflower tasks; no other behavioural differences were detected among the groups. Pyramidal cells in forelimb and cingulate areas as well as spiny neurons of the striatum were examined for dendritic branching and spine density using a Golgi-Cox procedure. Each lesion type had a different impact on cell morphology. Overall, different changes (atrophy or hypertrophy) were observed with each kind of lesion and these changes were specific for the region (forelimb, cingulate, striatum) and the condition (intact vs. damaged hemisphere). These results suggest that: (i) different lesions to the motor cortex produce subtle differences in behaviour, and (ii) the method used to induce the lesion produces striking differences in cortical and subcortical plasticity.
Gonzalez
C L R
CL
Department of Psychology and Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada. claudia.gonzalez@uleth.ca
Kolb
B
B
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D001921:Brain / Q000473:pathology*; D020520:Brain Infarction / Q000473:pathology; D003712:Dendrites / Q000473:pathology; D004195:Disease Models, Animal; D004467:Economics; D005552:Forelimb / Q000503:physiopathology; D007839:Functional Laterality; D006368:Helianthus; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology / Q000503:physiopathology; D008297:Male; D009474:Neurons / Q000473:pathology; D011597:Psychomotor Performance; D051381:Rats; D020318:Rats, Long-Evans; D020127:Recovery of Function; D016622:Silver Staining; D020521:Stroke / Q000473:pathology* / Q000503:physiopathology*; D013396:Suction / Q000379:methods; D013550:Swimming; D013997:Time Factors; D014059:Tongue / Q000503:physiopathology