It may be the world’s smallest EEG electrode cap; it’s used to track activity in a pen-dot-sized brain model. The inventors hope that their invention will aid in the understanding of neurological conditions and the effects of potentially hazardous chemicals on the brain.
This engineering feat, led by Johns Hopkins University researchers, expands the capabilities of organoids, such as mini brains, which are lab-grown balls of human cells that simulate some aspects of the structure and functionality of the brain.
One of the developers and chemical and biomolecular engineer David Gracias from Johns Hopkins University, said, “This provides an important tool to understand the development and workings of the human brain. Creating micro-instrumentation for mini-organs is a challenge, but this invention is fundamental to new research.”
Organoids were created more than ten years ago, and scientists have since modified stem cells to create miniature kidneys, lungs, livers, and brains. Organ development is studied using the intricate miniature models. Organoids that have been genetically altered, infected with a virus, or exposed to chemicals are studied alongside unaltered organoids. Since they can be used in experiments that would otherwise require human or animal testing, organoids, particularly mini-brains, are becoming progressively crucial in medical research.
Gracias further said, “But because the conventional apparatus to test organoids is flat, researchers have been able to examine only limited cells on their surface. Knowing what’s happening to a larger number of cells in the organoid would help understanding of how organs function and diseases progress.”
He added, “We want to get information from as many cells as possible in the brain, so we know the state of the cells, how they communicate and their spatiotemporal electrical patterns.”
The team was inspired by the electrode-dotted skull caps used to detect brain tumours and developed tiny EEG caps for brain organoids using self-folding polymer leaflets and conductive polymer-coated metal electrodes. The microcaps completely encircle an organoid’s spherical shape, allowing 3D recording from every surface. This enables researchers to listen to neurons’ spontaneous electrical communication while subjecting them to drugs, among other things.
Thomas Hartung, co-author and director of the Johns Hopkins Bloomberg School of Public Health Center for Alternatives to Animal Testing, claims that with more precise information from organoids, scientists can examine whether chemicals found in consumer products have an effect on brain development.