Brain cells at work

Until now it has been impossible to accurately measure the levels of important chemicals in living brain cells in real time and at the level of a single cell.

Scientists at the Carnegie Institution's Department of Plant Biology and Stanford University are the first to overcome this obstacle by successfully applying genetic nanotechnology using molecular sensors to view changes in brain chemical levels. The sensors alter their 3D form upon binding with the chemical, which is then visible via a process known as fluorescence resonance energy transfer (FRET).

In a new study, the nanosensors were introduced into nerve cells to measure the release of the neurotransmitter glutamate, the major brain chemical that increases nerve-cell activity in mammalian brains. It is involved in everything from learning and memory to mood and perception. Too much glutamate is believed to contribute to conditions such as Alzheimer's and Parkinson's disease. The research is published in the May 30-June 3 on-line early edition of the Proceedings of the National Academy of Sciences.