Multi-modal characterisation of the neocortical clip model of focal cerebral ischaemia by MRI, behaviour and immunohistochemistry.
The neocortical clip model of focal cerebral ischaemia has previously been used with success in neuroprotection studies. To further improve its translational qualities, we have characterised this model using a combination of serial Magnetic Resonance Imaging (MRI), neurological assessment, the bilateral asymmetry test (BAT) and immunohistochemistry. The right MCA was occluded in spontaneously hypertensive rats for 0, 60 and 120 min. MRI was performed pre-surgery, 1, 3 and 7 days post-surgery. Behavioural assessment was performed 2 days before and 3 and 7 days post-surgery whilst neurological deficits were monitored daily. Neuroimaging results showed that 0 min of MCA occlusion did not produce a lesion, whereas occlusion for 60 min produced a lesion that remained stable over time. Occlusion for 120 min caused a more severe lesion 1 day post-surgery, but decreased by 7 days. Behaviour, neurological scores and histological lesion volumes correlated strongly with MRI lesion volume. Immunohistochemistry revealed neuronal loss, astrogliosis and macrophage infiltration in lesioned cortices. The neocortical clip model produced ischaemic lesions that are restricted to cortical territories of the MCA. The duration of occlusion dictates lesion severity which may prove useful for probing therapeutic interventions at different stages of stroke progression. The correlation of MRI with two different behavioural measures and post-mortem histology strengthens the basis for MRI providing an in vivo surrogate marker for structural and behavioural deficits caused by a cortical stroke.
Ashioti
Maria
M
Neuroimaging Research Group, Department of Neurology-PO42, Institute of Psychiatry, Kings College London, De Crespigny Park, Denmark Hill, London SE5 8AF, UK. m.ashioti@iop.kcl.ac.uk
Beech
John S
JS
Lowe
Andrew S
AS
Hesselink
Mayke B
MB
Modo
Michael
M
Williams
Steve C R
SC
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D002545:Brain Ischemia / Q000175:diagnosis* / Q000378:metabolism / Q000503:physiopathology; D002634:Chemotaxis, Leukocyte / Q000502:physiology; D004268:DNA-Binding Proteins; D004195:Disease Models, Animal; D018450:Disease Progression; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis / Q000378:metabolism; D005911:Gliosis / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D007150:Immunohistochemistry; D020244:Infarction, Middle Cerebral Artery / Q000175:diagnosis* / Q000378:metabolism / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D020768:Middle Cerebral Artery / Q000293:injuries / Q000503:physiopathology / Q000601:surgery; D019579:Neocortex / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D009410:Nerve Degeneration / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000378:metabolism; D009460:Neurologic Examination; D009687:Nuclear Proteins / Q000032:analysis / Q000378:metabolism; D011237:Predictive Value of Tests; D051381:Rats; D011918:Rats, Inbred SHR; D020521:Stroke / Q000175:diagnosis* / Q000378:metabolism / Q000503:physiopathology; D013525:Surgical Instruments / Q000592:standards
D015415:Biomarkers; D004268:DNA-Binding Proteins; D005904:Glial Fibrillary Acidic Protein; D009419:Nerve Tissue Proteins; C492380:NeuN protein, mouse; D009687:Nuclear Proteins