Optical Probes Allow Ultrafast, High-Resolution Imaging of Dopamine Activity

Fluorescent sensors that optically record dopamine activity in the brains of behaving mice could help facilitate the discovery of therapeutics for depression and addiction. The technology precisely captures where and when dopamine activity occurs in the mouse brain within milliseconds and at the cellular level, producing a high-resolution map of dopamine transients associated with behaviors such as learning.

Scientists have developed a technology to capture when and where dopamine activity occurs in the brain. Courtesy of Laboratory of Lin Tian at UC Davis.

Named dLight 1, the genetically encoded dopamine indicator was used to report spatial and temporal release of dopamine with high resolution both in vitro and in vivo. The research team from the University of California, Davis imaged dopamine dynamics simultaneously using pharmacological manipulation, electrophysiological or optogenetic stimulation, and calcium imaging of local neuronal activity.

Neuroscientist Lin Tian and her team, (from left) Gerard Broussard, Tommaso Patriarchi, Tian, and Ruqiang Liang. Courtesy of UC Davis.

The indicator dLight1 enabled chronic tracking of learning-induced changes in millisecond dopamine transients in the striatum (the region of the brain that governs motor and reward systems). Researchers further used dLight1 to image dopamine transients relevant to learning and motor control in the cortex and were able to track the dynamic change of released dopamine during specific activities, such as running and reward learning.

The researchers believe that their sensors, combined with optical imaging techniques, could be useful for analyzing and engineering functional neural circuits associated with learning, memory, behavior, and disease states. The sensor design platform could be used for developing other neuromodulators, including norepinephrine, serotonin, melatonin, and opioid neuropeptide indicators.

The research was published in Science (doi:10.1126/science.aat4422).

An overview of new optical probe developed in the laboratory of Lin Tian at UC Davis and its importance to discovering effective and novel therapeutics for depression, addiction, and drug abuse. Courtesy of Laboratory of Lin Tian at UC Davis.