Cryopreservation of brain cell structure: a review

Area of Science:

• Neuroscience
• Histology
• Biotechnology

Background:

• Cryopreservation is essential for brain banking, enabling molecular studies without chemical fixatives.
• Ice crystal formation during cryopreservation can damage brain tissue's cellular morphology.
• Characterizing cryopreservation's effects on neurohistology is critical for optimizing tissue preservation.

Purpose of the Study:

• To comprehensively review and classify existing literature on the effects of cryopreservation on brain cell structure.
• To identify limitations and areas for improvement in current cryopreservation techniques for brain tissue.

Main Methods:

• Conducted a literature search identifying 97 studies with 146 observations on cryopreservation's impact on neurohistology.
• Classified reviewed studies into three categories: cryofixation, freezing, and cryopreservation with cryoprotectants.

Main Results:

• Cryofixation offers excellent ultrastructure for thin samples but is limited by tissue depth.
• Freezing methods, especially for brain slices, can minimize ice artifacts visible under light microscopy.
• Cryoprotectant immersion is effective for thin samples; perfusion is needed for larger tissues but has less evidence.

Conclusions:

• Current cryopreservation methods are adequate for some applications but require enhancement for larger brain samples.
• Further development is necessary to achieve high-quality structural preservation in larger cryopreserved brain tissues.