Aug 10 2010
A research team has developed a new technology to map the amount of oxygen present inside living animal brain tissues. The team, which included David Boas, a physicist from the Harvard Medical School, and Sergei Vinogradov from the Pennsylvania University, used a current imaging method known as two-photon microscopy. The new technology is a vital breakthrough to aid stroke patients.
The two-photon microscopy technique involves injecting a phosphorescent probe inside the brain. The probe, when excited by laser pulses of high frequency, discharges photons. The two-photon microscope identifies photons. While high-energy photons are generated, it can damage the brain cells, however, the two-photon excitation minimizes the damage, as the excitation of the phosphorescent probe happens in a small volume close to the laser. Measuring the consumption of oxygen deep inside the brains of living animals is still not possible because of technical limitations.
Sergei Vinogradov stated that they used a specially designed phosphorescent probe. In the probe, the two-photon antenna part harvests two-photon radiation and sends it to the other part of the probe, which discharges phosphorescence and detects oxygen.
The research team measured the oxygen level used inside the deep brain tissue with a high resolution of 30-50 micrometers. The team was also able to determine how the tissues use the brain oxygen, by preventing the mouse from breathing temporarily.
Source: http://hms.harvard.edu/