Researchers view live synapse formation for the first time

Researchers from the Max Planck Institute for Neuroscience in Jupiter, Florida have designed a method to visualize the formation of new synapses in mice using photon imaging.

According to a study from the Max Planck Institute for Neuroscience in Jupiter, Florida, published in the August issue of Science., the technique could uncover information critical to developing new therapies for developmental disorders, according to Hyung-Bae Kwon, PhD, and colleagues.

Adult brains have as many as 1,000 trillion synapses connecting neurons together, giving the brain the computing power equivalent to a thousand-petaflop processer—20 times faster than the world’s fastest supercomputer. Synapses are either excitatory or inhibitory, but the rules that govern their spatial arrangement are unknown. This spatial distribution is critical for neurons’ abilities to process information, and any abnormal distribution could affect behavior, sensation and cognition.

“We induced and visualized the formation of new synapses using two-photon imaging and two-photon photolysis of neurotransmitter,” said Kwon. “With a pulse of two-photonlaser light in precise locations, we could release a small amount of GABA (a neurotransmitter) which can initiate GABA-mediated signaling cascade at single synapse resolution. Such that, we were able to monitor the process of single synapse formation.”

The photon imaging method will give researchers a new window into the critical period where both types of synapses are formed on branches of neurons. According to co-author Won Chan Oh, PhD, these findings suggest a model where GABA is the molecule that defines whether a synapse will be inhibitory or excitatory in the formation stage.

“Given that abnormal synapse formation causes various neurodevelopmental diseases such as autism spectrum disorders and epilepsy, understanding activity-dependent mechanisms of initial synapse formation will be important for developing new therapeutic strategies for these conditions,” explained Dr. Kwon.

Learn more about the study and the Max Planck Institute for Neuroscience at the official webpage.