Dopamine Release Neuroenergetics in Mouse Striatal Slices

Published: June 3, 2020, 11 p.m.

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.06.02.130328v1?rss=1 Authors: Msackyi, M., Chen, Y., Tsering, W., Wang, N., Zhao, J., Zhang, H. Abstract: Parkinson's disease (PD) is the second most common neurodegenerative disease. Dopamine (DA) neurons in the substantia nigra par compacta with axonal projections to the dorsal striatum (dSTR) degenerate in PD while in contrast, DA neurons in the ventral tegmental area with axonal projections to the ventral striatum including the nucleus accumbens (NAcc) shell, are largely spared. To understand the pathogenesis of PD, it is important to study the neuroenergetics of DA neurons. This study aims to uncover the relative contribution of glycolysis and oxidative phosphorylation (OxPhos) to evoked DA release in the striatum. We measured evoked DA release in mouse striatal brain slices by fast-scan cyclic voltammetry every 2 minutes. Blocking OxPhos caused a greater reduction in evoked DA release in the dSTR compared to the NAc shell, and blocking glycolysis caused a greater reduction in evoked DA release in the NAcc shell than in the dSTR. Furthermore, when glycolysis was bypassed in favor of direct OxPhos, evoked DA release in the NAcc shell was decreased by ~50% over 40 minutes whereas evoked DA release in the dSTR was largely unaffected. These results demonstrated that the dSTR relies primarily on OxPhos for energy production to maintain evoked DA release whereas the NAcc shell relies more on glycolysis. Using two-photon imaging, we consistently found that the oxidation level of the DA terminals was higher in the dSTR than in the nAcc shell. Together, these findings partially explain the specific vulnerability of DA terminals in the dSTR to degeneration in PD. Copy rights belong to original authors. Visit the link for more info