By implanting a tiny microscope in the brain of a mouse Stanford researchers have been able to monitor its brain activity.
The study links the observed neuron activity with long-term information storage and could be used to develop treatments and therapies for neurodegenerative conditions in humans.
The technique involved genetically engineering the mice to contain a green fluorescent protein. The protein was created to react to the presence of calcium ions so, when the neuron fired and the cell naturally flooded with those ions, the cells fluoresced green.
A little microscope positioned just above the hippocampus in the mouse's brain could then capture the activity and send it to a computer screen for near real-time monitoring as the mouse runs around a little arena.
"We can literally figure out where the mouse is in the arena by looking at these lights," said biologist Mark Schnitzer, senior author on the paper which has been published in the journal Nature Neuroscience.
"The hippocampus is very sensitive to where the animal is in its environment, and different cells respond to different parts of the arena. Imagine walking around your office. Some of the neurons in your hippocampus light up when you're near your desk, and others fire when you're near your chair. This is how your brain makes a representative map of a space."
These patterns of firing in the mouse brain were found to stay consistent even after weeks had passed between tests. This consistency is what makes it possible to use the technique as a tool with which to study progressive brain diseases and evaluate the effectiveness of some types of treatment and therapy.