Michael A. Johnson named November 2022 Sutton Family Research Impact Award recipient

The Department of Chemistry congratulates Associate Professor Michael A. Johnson on receiving the November 2022 Sutton Family Research Impact Award!

The Sutton Award is a monthly competition among chemistry faculty. Every month, the Chemistry Department Chair and Associate Chairs review the peer-reviewed papers published by chemistry faculty from the three previous months to select a winner. The recipient receives a $500 cash prize and is featured on the departmental website.

For a full list of winners, visit our Sutton Family Research Impact Award webpage.

Characterization of D3 Autoreceptor Function in Whole Zebrafish Brain with Fast-Scan Cyclic Voltammetry

By Piyanka Hettiarachchi and Michael A. Johnson

Published in: ACS Chem. Neurosci. 2022 13 (19), 2863-2873

While the release of dopamine in the brain may provide a feeling of euphoria, the close regulation of this neurotransmitter is crucial to controlling these positive effects. The Johnson Research Group received the November 2022 Sutton Family Research Impact Award for their work on understanding how this regulation occurs in a powerful new model of neurological function—zebrafish (Danio rerio). In their paper, entitled “Characterization of D3 Autoreceptor Function in Whole Zebrafish Brain with Fast-Scan Cyclic Voltammetry” (Hettiarachchi P. and Johnson M. A., ACS Chem. Neurosci. 2022 13 (19), 2863-2873), they examined how the D3 autoreceptor, which binds to dopamine and acts as a feedback mechanism to inhibit its release, functions in zebrafish.

In this work, Piyanka Hettiarachchi, a graduate student mentored by Dr. Michael Johnson, measured the release and uptake of dopamine in living, whole zebrafish brains with a technique called fast-scan cyclic voltammetry (FSCV). This technique employs micron-size electrodes to pull electrons from dopamine molecules. Monitoring the resulting electrical current provides a measurement of dopamine concentration. By activating and blocking the D3 receptor with select drugs, they assessed the effects of D3 receptor activation and inhibition on dopamine release and uptake. In this way, they showed that activating D3 receptors inhibits dopamine release, while inhibition of these receptors not only inhibits release, but also inhibits uptake. Furthermore, they observed that blocking dopamine uptake with nomifensine reversed decreases in release caused by D3 activation.

Collectively, their data show that, as in mammals, zebrafish D3 autoreceptors regulate DA release in part by inhibiting uptake. The results of this study are useful in the further development of zebrafish as a model organism for DA-related neurological disorders such as Parkinson’s disease, schizophrenia, and drug addiction.