Definition of opacity for English Language Learners. : 1  the quality of a material that does not allow light to pass through it : the quality of being opaque. : 2  the quality of being difficult to understand or explain.
Research has shown that this is not true, and that brain cells can and do regenerate, especially in the areas related to learning, decision-making, visual recognition, and the way people perceive objects in space.weet. For a long time, scientists thought that it was impossible for brain cells to regenerate because they assumed that any new cells would disrupt the order of the brain.
Scientists have used supporting cells of the central nervous system, glial cells, to regenerate from damaged cells the healthy and functional neurons that are critical for transmitting signals in the brain, shown in green in this image in the brain of a mouse with Alzheimer's disease.- Researchers at Penn State have developed an innovative technology to regenerate functional neurons after brain injury and also in model systems used for research on Alzheimer's disease.