Effects of esketamine on electrophysiology and metabolic reprogramming in brain organoids: insights into antidepressant mechanisms

Abstract

Esketamine, commonly used to treat treatment-resistant depression, has pharmacological mechanisms that remain incompletely understood. Brain organoids offer a human-relevant platform for investigating the cellular and molecular effects of drugs. In this study, we investigated the effects of esketamine on the electrophysiology and metabolism of brain organoids derived from iPSCs of healthy control subjects and depressed patients. Continuous monitoring revealed that esketamine treatment significantly decreased both the frequency and amplitude of action potentials, with the most pronounced reduction occurring within 4 h. High concentrations (1.5 mg/L) produced a stronger inhibitory effect, while organoids treated with a low concentration (0.25 mg/L) showed a recovery in action potential frequency after one week, although levels remained below pre-treatment values—a recovery not observed in the high-concentration group. Single-cell RNA sequencing demonstrated that esketamine modulated energy metabolism and induced metabolic reprogramming in a concentration- and time-dependent manner. Furthermore, by inhibiting oxidative phosphorylation and glycolysis separately and assessing cytosolic Ca²⁺ levels, we found that esketamine may regulate NMDAR activity and electrophysiology through energy metabolism pathways. These findings reveal a potential mechanism for esketamine’s effects and offer new insights for clinical treatment strategies.