Electrochemical Studies on Effects of Psychostimulants, Opioids and Alcohol Intake Towards Level of Hydrogen Peroxide in the Brain Striatum

Hydrogen peroxide (H 2 O 2 ) was the main types of many peroxides produced in living mammalian cells that consumed oxygen. In the brain, the main source of H 2 O 2 was the superoxide dismutase (SOD)‐catalyzed reaction in mitochondria. However, the level of H 2 O 2 would be elevated through administration of control drugs and alcohol by dopamine metabolism of monoamine oxidase. In this study, a H 2 O 2 microsensor was used to investigate the level of H 2 O 2 in the brain striatum after administration of methamphetamine (MAP), morphine (MrP) or ethanol (Eth). The placement of microsensor in the brain was done at coordinates A/P 1.1 from bregma, M/L+2.6 and D/V‐1.5. A working potential of +0.05 V vs. Ag/AgCl was applied. The H 2 O 2 concentration was measured direct from the current generated by its catalytic reaction at the electro active surface of the electrode. A significant increase of H 2 O 2 level was observed after 7 successive injections of the controlled drugs or alcohol. The initial measurement of H 2 O 2 is essential as excess dosage of H 2 O 2 during treatment will contribute to the formation of neurotoxin oxygenated radicals. The H 2 O 2 was the precursor of O 2− and OH radicals. Thus, this study provided a mean to monitor H 2 O 2 level in the brain.