A team of international researchers has developed new tissue-clearing protocols for the 3D imaging of human brain tissue that may help answer questions around microstructural anatomy.
The study was published online March 14 in Nature Communications.
“We have developed a selection of protocols for the study of human brain tissue in 3D, which are flexible and versatile for use by histopathologists to address different research questions concerning microstructural anatomy in health and disease,” wrote corresponding author Steve M. Gentleman, with the division of brain sciences at the Imperial College of London, and colleagues. “These strategies are simple to execute and will hopefully provide the basis for further technique development.”
Of modern clearing techniques for 3D visualization of brain tissue, many are only effective in rodent tissue because they were not originally developed on human pathological samples.
While a variety of imaging modalities are adept at providing understanding of the human brain, tissue clearing is superior for studying neuropathology in 3D.
The group, made up of U.K. and Chinese scientists, tested a one mm-thick piece of formalin-fixed human brain tissue in its Optical Properties-adjusting Tissue-Clearing (OPTIClear) agent for six hours. Results showed the agent efficiently cleared the tissue with minimal structural disturbance.
Researchers also created established guidelines to address the problems in immunostaining.
“In light of practical challenges with immunostaining in tissue clearing, we adapt the use of cresyl violet for visualization of neurons in cleared tissue, with the potential for 3D quantification in regions of interest,” Gentleman et al. wrote. “Furthermore, we use lipophilic tracers for tracing of neuronal processes in post-mortem tissue, enabling the study of the morphology of human dendritic spines in 3D.”
The findings and methods developed in this study can perform tissue clearing on prolonged formalin fixed and paraffin-embedded tissues which provides “huge potential for accessing and using diagnostic archives for research purposes particularly for rare neurological disorders,” according to Gentleman et al.
Matt joined Chicago’s TriMed team in 2018 covering all areas of health imaging after two years reporting on the hospital field. He holds a bachelor’s in English from UIC, and enjoys a good cup of coffee and an interesting documentary.