Two histological methods for recognition and study of cortical microinfarcts in thick sections

Area of Science:

• Neuropathology
• Neuroimaging
• Cerebrovascular Diseases

Background:

• Cortical microinfarcts are common but often undetected by standard neuroimaging.
• Conventional H and E staining of thin sections has limited sensitivity for microinfarcts.

Purpose of the Study:

• To develop and present two novel staining protocols for enhanced visualization of cortical microinfarcts.
• To enable detailed neuropathological examination of microinfarcts in thicker brain sections (100-300 µm).

Main Methods:

• Protocol 1: Aldehyde fuchsine and Darrow red staining for macrophages and Nissl material.
• Protocol 2: Collagen IV immunohistochemistry combined with aldehyde fuchsine/Darrow red or erythrosin-phosphotungstic acid-aniline blue staining for capillary network analysis.

Main Results:

• Protocol 1 identifies microinfarcts as radial accumulations of aldehyde fuchsine-positive macrophages.
• Protocol 2 visualizes microinfarcts, associated capillary network alterations, and clusters of dead neurons and macrophages.
• The second protocol highlights abnormalities in the capillary network of recent microinfarcts.

Conclusions:

• The developed staining protocols significantly improve the detection and characterization of cortical microinfarcts.
• These methods facilitate correlation between MRI findings and neuropathological examination of thicker brain sections.
• Enhanced visualization aids in understanding the pathology of microinfarcts and their vascular associations.