New nanosensor gives unprecedented look at dopamine release

Astronomers use telescopes to look at the night sky. Abraham Beyene looked at the cells that made up the human brain.

Beyene and his team design and make new types of biosensors that they can use to peer at the brain.

Beyene says, "You have this new tool that helps us make the kinds of measurements that we've never been able to make before, and we go into the lab and deploy this technology." Some really interesting phenomena begin to emerge that you haven't even thought about.

Beyene and his team use this approach with their new syntheticnanosensor designed to capture dopamine release across entire neurons with subcellular resolution The biosensor is attached to a film and the cells are grown on top of it. The chemical dopamine falls onto the film when it is released by the neuron. A custom-built microscope is used by the team to see dopamine release from any part of the neuron and create movies to capture the chemicals as they diffuse out.

The long chain from the axons of the neuron to the cell body is called a transmitter. The soma and its dendrites release dopamine and other neurotransmitters. Traditional methods could not give a good enough look at how dopamine is released from the soma and dendrites.

Scientists can only observe what is happening at certain points on the cell with traditional biosensors. Beyene's sensor is able to record the release of chemicals across a single neuron. The sensor's sensitivity to dopamine allows it to detect the smallest part of the signal from the cells.

The team was able to capture the release of dopamine. For the first time, they can see the release of dopamine from specific locations on dendrites thanks to the new technique.

Their work gives scientists an opportunity to take a fresh look at dopamine release from dendrites, and suggests these structures may play a bigger role in brain computations than previously thought.

The ability to create movies where we capture the full spatial and temporal extent of chemicals as they get released and diffuse has never been done before. Beyene says that they took advantage of the ability to study the release of dopamine.

Beyene says that the new work raises new questions such as why some dendrites release dopamine while others don't. He hopes their findings will lead to more research into dopamine neurons.

The role of dopamine release in larger computation has not been fully explored because most tools struggle to give a good measurement and visualization of release from dendrites. Beyene hopes that the study will encourage researchers to take another look.

More information: Chandima Bulumulla et al, Visualizing synaptic dopamine efflux with a 2D composite nanofilm, eLife (2022). DOI: 10.7554/eLife.78773 Journal information: eLife