UCLA neuroscientists have collaborated with physicists to develop a non-invasive, ultra-high-speed microscope that can record in real time the firing of thousands of individual neurons in the brain as they communicate, or miscommunicate, with each other.

The imaging technology they developed is called multifocal two-photon microscopy with spatio-temporal excitation-emission multiplexing - STEM for short. The researchers modified two-photon laser-scanning microscopes to image fluorescent calcium dyes inside the neurons, and came up with a way to split the main laser beam into four smaller beamlets. This allowed them to record four times as many brain cells as the earlier version. In addition, the team used a different beam to record neurons at different depths inside the brain, giving a 3D effect.

Even the best imaging devices available - fMRIs and PET scans - can only give a "coarse" picture of brain activity. The scientists will use the UCLA microscope to visualize brain activity and understand the root of disorders, such as autism and schizophrenia, which show no physical signs of damage and are believed to be caused by problems in how brain cells communicate with one another.