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.
Cooling saves lifes after a heart attack. Taking the body down to a hypothermic state within hours can save not only heart muscle but improve the severity of a brain injury.Within four minutes of a heart attack brain cells begin to die off.Doctors have had the technology for several years for therapeutic hypothermia.aking the body down to a hypothermic state within hours can save not only heart muscle but improve the severity of a brain injury. Within four minutes of a heart attack brain cells begin to die off. Doctors have had the technology for several years for therapeutic hypothermia.