Many factors jeopardize normal brain development. Disturbances to brain oxygenation and circulation are among the leading causes. The human brain is exquisitely sensitive to changes in the amount of oxygen that we breathe. Exposure to either low levels (hypoxia) or high levels (hyperoxia), if even for a brief duration, lead to immediate changes in brain function. Long term exposure to hypoxia or hyperoxia evokes changes in brain structure and function.
Clinical disorders can induce low oxygen levels in the bloodstream (hypoxemia). Examples include reduced cardiac output (cardiac disease, cardiogenic shock, etc.), lung disease, central nervous dysfunction (including drug overdose), premature birth accompanied by underdeveloped lungs, etc.
Environmental conditions can also lead to low levels of oxygen within the body. These include traveling through or living in high altitude environments (Leadville, Colorado, Tibetan Himalaya, Bolivia Altiplano, Ethiopian Semiens). Certain occupations may also require that people live or work in slightly reduced oxygen environments, to reduce fire hazards, such as submarines.
Throughout the course of evolution, humans have developed physiologic strategies to adapt to low oxygen levels. These include changes in ventilation and red blood cell mass. In sharp contrast, there is no place on Earth in which naturally occurring oxygen levels exceed 21%. Consequently, humans may not be able to adapt to high oxygen levels.
As high levels of oxygen are also a prerequisite to survival during high-speed, high altitude aviation, extravehicular activities around the international space station, or undersea diving; there is a growing need to understand the impact of hyperoxia upon brain structure and function.
Our ongoing program of research is focused upon characterizing structural and functional changes occurring within the human brain before, during and after exposure to hypo- and hyperoxia.Principal Investigator: Michael J. Decker, PhD