Device maps electrical activity of brain cells in a dish
Neural Networks
Diseases of the brain have eluded effective treatment, because the brain is such a complex organ, explained Dr Jim Ross, chief technology officer and co-founder of Axion BioSystems, in an article in Drug Discovery World. While medical advances are helping researchers to understand the brain and address neurological disease, medical science lacks understanding of the etiology at the cellular and molecular level to effectively mitigate symptoms or halt and reverse damage for diseases such as epilepsy, amyotrophic lateral sclerosis (ALS) and Alzheimer’s, he said.
Because the brain is composed of tens of billions of electroactive neurons that pass electrical and chemical signals to one another, it is difficult to find cellular changes and molecular abnormalities causing a disease. As Ross said, “Signaling between neurons forms neural circuits and complex networks that together govern the body’s physiology. The cells, circuits, and networks all have distinct roles that contribute to the brain’s overall functionality. While neuroscientists have found creative ways to map and decipher this organ, roadblocks have stifled key advances in understanding the link between the brain’s structure and function – and how these attributes contribute to health and disease.”
One in every 100 newborns is diagnosed with pediatric epilepsy. Many neurological diseases can strike later in life: ALS affects one in every 50,000 middle-aged people. Alzheimer’s usually affects the elderly.
Currently available methods fail to give fast or clear insight into the cellular and molecular mechanisms underlying these diseases and to capture the complex signaling network underlying the system as a whole. Recent advances have produced a technology that relies on microelectrode arrays (MEAs) that make conducting electrophysiology experiments more accessible, enabling seasoned neuroscientists and novices to run long-term experiments and conduct analyses that yield detailed insight into neural networks over time.
The MEA technology, developed by Axion BioSystems, is designed to map the electrical activity of cells in a dish. To run an MEA experiment, scientists culture cells in a multi-well plate that has closely spaced electrodes embedded in the bottom of each well. The technology maintains delicate surface contact with electrically active cells and detects changes noninvasively so as not to damage the cells. The MEA reader mimics the environment of a cell culture incubator, so that the cellular activity is measured reliably over the lifespan of the culture, from days to months. Axion’s MEA technology complements in vitro electrophysiology approaches that give insight into the behavior of individual cells, enabling researchers to ask additional layers of questions about how those cells interact.
This technique is designed to capture cells in a state that emulates how cells behave in the brain. Neurons and other electrically active cells may be cultured directly in the MEA plate, giving them time to form a network. The multi-well format enables experiments that require multiple replicates or call for multiple variables to be tested. Unlike lower-throughput electrophysiology techniques, a single multi-well MEA plate can simultaneously measure electrical changes induced by multiple genetic, environmental, and pharmacological variables. The technique is also easy to learn: Anyone who has been trained to use cell cultures can conduct an MEA assay.