Mechanism of anoxic depolarization in the brain disruption. Other consequential damage that occurs includes lipolysis, proteolysis, cell swelling, microtubule disaggregation, and DNA fragmentation. Neurons are more susceptible to brain ischemia than the supporting glial cells, because neurons have higher energy demand, conduct an action potential, and produce glutamate, whereas glial cells lack those properties. Yet neurons differ among themselves in their sensitivity to ischemia, depending on the specific properties they exhibit, relating to their locations in the brain. "Selective vulnerability" is the term used to describe how some parts of the brain are more sensitive to anoxia than others, and thus to ischemic insult. Anoxia-prone cells in
Effect of spaceflight on the human body lymphocytes. As these cells are central to the immune system, any damage weakens the immune system, which means that in addition to increased vulnerability to new exposures, viruses already present in the body—which would normally be suppressed—become active. In space, T-cells (a form of lymphocyte) are less able to reproduce properly, and the T-cells that do reproduce are less able to fight off infection. Over time immunodeficiency results in the rapid spread of infection among crew members, especially in the confined areas of space flight systems. On 31 May 2013, The NASA scientists reported that a possible manned mission to