Associate Professor Michael A. Johnson named July 2025 Sutton Family Research Impact Award recipient
The Department of Chemistry congratulates Associate Professor Michael A. Johnson on receiving the July 2025 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.
Zinc-Dependent Modulation of Dopamine Release and Uptake Is Altered in Parkinson’s Disease Model Zebrafish
By Piyanka Hettiarachchi, Austin Shigemoto, Erin E. Hickey, Shawn C. Burdette, and Michael A. Johnson
ACS Chem. Neurosci. 2025, 16(10): 1872-1882. https://doi.org/10.1021/acschemneuro.4c00864
Parkinson’s disease (PD) is a progressive central nervous system disorder characterized by motor and non-motor symptoms. The pathophysiology of PD involves the loss of neurons that release and take up dopamine, a chemical messenger. Interestingly, the release of zinc ions (Zn2+) by neurons located adjacently to dopamine-releasing neurons exert control over this release and uptake process. In their paper, entitled “Zinc-dependent modulation of dopamine release and uptake is altered in Parkinson’s disease model zebrafish” (Hettiarachchi et al. ACS Chem Neurosci. 2025, 16(10):1872-1882), the Johnson Research Group sought to identify differences in how Zn2+ regulates dopamine release and uptake in zebrafish that model PD versus controls.
Dr. Piyanka Hettiarachchi combined an electrochemical technique called fast-scan cyclic voltammetry (FSCV) with the light-induced cleavage of zinc-bound photocages in freshly removed zebrafish whole brains. The zinc photocages were designed and synthesized by Dr. Shawn Burdette and team at Worcester Polytechnic Institute. This method allows the measurement of dopamine release and uptake, and the effects of Zn2+ photorelease on these parameters, with millisecond temporal precision. We found that when zebrafish were treated with rotenone to model PD the ability of Zn2+ to inhibit dopamine reuptake was diminished. However, in PD model fish, but not controls, Zn2+ photorelease caused a decrease of dopamine release. Short term treatment of brains with TEMPOL, which scavenges superoxide, a potentially free radical, had no effect on uptake, but rescued release. Our results suggest that, in PD model fish, the dopamine transporter undergoes permanent modification while the release mechanisms are only temporarily affected. Our work represents the first to study sub-second timescale functional zinc signaling and how it is influenced by PD.
