The National Institutes of Health (NIH) is getting into Botox — not as a beauty aide, but as a tool to study the brain. In a new study published in Cell Reports, researchers at NIH's National Institute of Neurological Disorders and Stroke (NINDS) describe how they used Botox to discover a novel role for a group of molecules in the brain, according to an NIH press release. Knowing how nerve cells use these molecules, called SNARES, to send messages between synapses could help researchers understand how brain cells communicate in healthy brains compared to diseases brains.

Originally, says NINDS researcher Ling-Gang Wu, researchers thought SNARES were only involved in fusion — a process whereby signaling chemicals called neurotransmitters, which are carried inside spherical membranes called synaptic vesicles, fuse with a nerve cell's plasma membrane to release the neurotransmitter into the synapse and deliver a chemical message. These carrier shells — vessels that contain the neurotransmitters — must be retrieved by a nerve cell before another message can be sent.

SNARE proteins (red, green, and blue) are known to help nerve cells send messages by releasing signaling chemicals. Now, researchers think they may also help retrieve neurotransmitter carrier shells, to prepare nerves to receive more messages. Courtesy of NINDS.

While SNARES are integral to fusion, and therefore synaptic transmission, the researchers found that this group of proteins also retrieve messenger carrier shells from nerve cell membranes immediately after they're released, NIH says.

For their study, the team used Botox and similar toxins on a synapse involved with hearing. They found something they expected — that the toxins reduced fusion — but also something they didn't expect: the toxins also reduced retrieval of the carrier shells. Further, the researchers add, SNARES may be involved in both the fast and slow modes of retrieval. It had always been thought that these two modes of retrieval were controlled by completely different sets of molecules.

The results could change how researchers think of the brain's communications systems, particularly how SNARES are involved in diseases like schizophrenia.