Optogenetics captures neuronal transmission in live mammalian brain

Swiss scientists have used a cutting-edge method to stimulate neurons with light. They have successfully recorded synaptic transmission between neurons in a live animal for the first time.

Neurons, the cells of the nervous system, communicate by transmitting chemical signals to each other through junctions called synapses. This "synaptic transmission" is critical for the brain and the spinal cord to quickly process the huge amount of incoming stimuli and generate outgoing signals.

However, studying synaptic transmission in living animals is very difficult, and researchers have to use artificial conditions that don't capture the real-life environment of neurons. Now, EPFL scientists have observed and measured synaptic transmission in a live animal for the first time, using a new approach that combines genetics with the physics of light. Their breakthrough work is published in Neuron.

Aurélie Pala and Carl Petersen at EPFL's Brain Mind Institute used a novel technique, "optogenetics", that has been making significant inroads in the field of neuroscience in the past ten years. This method uses light to precisely control the activity of specific neurons in living, even moving, animals in real time. Such precision is critical in being able to study the hundreds of different neuron types, and understand higher brain functions such as thought, behavior, language, memory - or even mental disorders.