Researchers from Imperial College London and The University of Hong Kong have published results in Nature Communications of a revolutionary process that renders human brain tissue transparent and allows the complex network of neurons to be mapped. This technique of clearing alters brain tissue’s optical properties without impacting the cell structure, allowing neurons to be examined more efficiently than conventional methods of slicing the tissue into microscopic sections, a process that can take weeks.
Once cleared, the brain tissue can be stained for nerve and glial cells, as well as blood vessels, and imaged to offer a glimpse of neurological diseases with unprecedented levels of complexity and detail from millimeter to cellular scales. Other pathological markers, such as the tau protein tangles associated with Alzheimer’s, can also be stained and used to reveal the intricate details of disease progression.
OPTIclear (Optical Properties-adjusted Tissue-Clearing agent) was optimized for clearing human brain tissue, a process that until now had only been done successful in rodents. The solution was developed to accommodate the variable refractive index of human brain tissue and was shown to be effective on both fresh tissue and archival samples. The possibility of analyzing tissue that has been preserved for decades could also enable research into numerous rare neurological disorders.
“We hope that a better understanding of the connections and circuitries of the brain will help uncover the pathologies that underlie the common degenerative diseases of the brain, such as Alzheimer’s and Parkinson’s disease,” commented Prof Wutian Wu from Hong Kong University.
The research team behind OPTIclear report that the method is applicable to other human organs, where it could aid in the study of other diseases at new levels of detail and “help unravel the mysteries of the human body.”
Open access study in Nature Communications: Next generation histology methods for three-dimensional imaging of fresh and archival human brain tissues…