NeuroScience Associates

Stroke Pathology: Ischemia Contrast

Applications:

• This stain reveals the volume of affected brain tissue following ischemia.

Advantages:

• Brains can be perfusion or immersion fixed.
• Non-ischemic tissue remains intensely dark.
• Affected tissue is pale, retaining less of the stain.
• A density gradient is seen in marginally affected tissue, i.e. penumbra.
• Other unstained, adjacent MultiBrain® sections are available for other stains.

Please note: This stain is performed exclusively by NSA

Specifications:

• Use NSA’s perfusion protocols for optimized staining.

**NSA performs a digital analysis service on this stain as well.

Appearance of Stroke in Popular Animal Models With Decreasing Severity

Abstract of Interest:

ISCHEMIA CONTRAST STAIN: A CLEAR WAY TO DELINEATE PENUMBRA FOLLOWING TRANSIENT FOCAL CEREBRAL ISCHEMIA

R.C. SWITZER III, PhD. NeuroScience Associates, Knoxville, TN 37922

H. KOENIG, MD. Dept. of Anesthesiology, Michael Reese Hospital,

Univ. of Illinois at Chicago, Chicago, IL 60610

Protective effects of interventions after stroke are ideally based on clinical neurologic outcomes and subsequent neurohistology. In small animal stroke models, difficulties with long survival times and neurologic evaluation prompt many investigators to perform acute studies and determine protection by histologic evaluations immediately after inducing an infarction. Many stains have been used to identify infarct areas but it is not clear if these areas include or could delineate the penumbra, i.e. the potentially salvageable tissue at the infarct’s border. The TTC method, for instance, is known to give variable infarct volumes depending on how long after the infarct the tissue is harvested. A fortuitous observation led to a staining method that delineates the penumbra and highlights the infarcted volume in sharp contrast. Formalin fixed brains from transient MCA-occluded rats were freeze sectioned (40µ), mounted and stained with a modified method for myelin. Normal tissue is dense black, infarcted areas fail to stain, and gradations of gray identify the penumbra zone. Section images are digitized and, based on optical density; the volumes of the infarct, penumbra and normal brain are calculated. Adjacent sections stained with other methods including H&E, thionine, and immuno-GFAP display less definition of affected areas.

The first published description of the results of this protocol was as an abstract for the 23rd Annual Meeting of the Society of Neurosurgical Anesthesia and Critical Care 1995.

Current contact information for Dr Heidi Koenig:

Dr Heidi Koenig
Anesthesiology-Conc. Care
530 S Jackson St
Louisville KY 40202-3617
hmkoen01@louisville.edu

For further reference, please see: Stains