title: Characterization of Behaviour and Remote Degeneration Following Thalamic Stroke in the Rat.
abstract: Subcortical ischemic strokes are among the leading causes of cognitive impairment. Selective atrophy of remote brain regions connected to the infarct is thought to contribute to deterioration of cognitive functions. The mechanisms underlying this secondary degenerative process are incompletely understood, but are thought to include inflammation. We induce ischemia by unilateral injection of endothelin-I into the rat dorsomedial thalamic nucleus, which has defined reciprocal connections to the frontal cortex. We use a comprehensive test battery to probe for changes in behaviour, including executive functions. After a four-week recovery period, brain sections are stained with markers for degeneration, microglia, astrocytes and myelin. Degenerative processes are localized within the stroke core and along the full thalamocortical projection, which does not translate into measurable behavioural deficits. Significant microglia recruitment, astrogliosis or myelin loss along the axonal projection or within the frontal cortex cannot be detected. These findings indicate that critical effects of stroke-induced axonal degeneration may only be measurable beyond a threshold of stroke severity and/or follow a different time course. Further investigations are needed to clarify the impact of inflammation accompanying axonal degeneration on delayed remote atrophy after stroke.
authors.affiliation: Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada. nweishau@uwo.ca.
authors.forename: Nina
authors.initials: N
authors.lastname: Weishaupt
authors.affiliation: Clinical Neurological Sciences, London Health Sciences Centre, University of Western Ontario, London, ON N6A 5A5, Canada. patoriccio@gmail.com.
authors.forename: Patricia
authors.initials: P
authors.lastname: Riccio
authors.affiliation: Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada. dobbst@outlook.com.
authors.forename: Taylor
authors.initials: T
authors.lastname: Dobbs
authors.affiliation: Clinical Neurological Sciences, London Health Sciences Centre, University of Western Ontario, London, ON N6A 5A5, Canada. vladimir.hachinski@lhsc.on.ca.
authors.forename: Vladimir C
authors.initials: VC
authors.lastname: Hachinski
authors.affiliation: Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada. shawn.whitehead@schulich.uwo.ca.|Clinical Neurological Sciences, London Health Sciences Centre, University of Western Ontario, London, ON N6A 5A5, Canada. shawn.whitehead@schulich.uwo.ca.
authors.forename: Shawn N
authors.initials: SN
authors.lastname: Whitehead
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000473:pathology; D001369:Axons / Q000473:pathology*; D001522:Behavior, Animal; D002545:Brain Ischemia / Q000503:physiopathology*; D008297:Male; D017628:Microglia / Q000473:pathology*; D009186:Myelin Sheath / Q000473:pathology*; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000502:physiology*; D020521:Stroke / Q000503:physiopathology*
keywords: axonal degeneration; executive function; frontal cortex; inflammation; secondary damage; subcortical ischemia