Harvard researchers have confirmed that eyes are windows of the brain, by describing the development of gene probe eye drops, which make it possible to monitor and identify tissue repair in the brain of living organisms using MRI.
Present methods are not very effective as they involve a risky, invasive, and relatively slow process of penetrating the skull to extract tissue samples and then examining those samples in a laboratory.
"We hope our study provides a tool for better treatments of neurological diseases, diagnosis, prognosis during therapy, and improved delivery of therapeutic agents to the brain," said Philip Liu of Harvard, co-author of the study.
Liu also said that further studies are needed to determine exactly how these gene probes reach brain tissue.
In the current study, Harvard researchers explain how they link a relatively common MRI probe (superparamagnetic iron oxide nanoparticles) to a short DNA sequence that binds to proteins in cells responsible for brain tissue repair (glia and astrocytes).
Then, they used the eye drops on mice with conditions that cause 'leaks' in the blood-brain barrier.
The researchers scanned animals' brains using MRI and found that brain repair activity was visible.
Glia and astrocytes are responsible for repairing brain and nerve tissue, and have a role in numerous diseases and disorders that cause at least microscopic breaches in the blood-brain barrier, including traumatic brain injury, multiple sclerosis, stroke, cardiac arrest, and glioma, among others.
In addition, researchers believe that the probes may also help diagnose thinning of vascular walls in brains, which occurs as Alzheimer's disease progresses.
The study was published in the April 2008 print issue of The FASEB Journal.