Electrophysiological biomarkers of antidepressant response to ketamine in treatment-resistant depression: Gamma power and long-term potentiation

• Published in: Pharmacology, biochemistry and behavior Vol. 189; p. 172856
• Main Authors: Gilbert, Jessica R., Zarate, Carlos A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2020
• Subjects: Animals; Antidepressive Agents - pharmacology; Antidepressive Agents - therapeutic use; Biomarkers; Depressive Disorder, Treatment-Resistant - drug therapy; Dynamic causal modeling; Electrophysiology; Gamma; Gamma Rhythm - drug effects; Humans; Ketamine; Ketamine - pharmacology; Ketamine - therapeutic use; Long-term potentiation; Long-Term Potentiation - drug effects; Synaptic Potentials - drug effects; Electrophysiology; Gamma; Ketamine; Dynamic causal modeling; Long-term potentiation
• ISSN: 0091-3057; 1873-5177; 1873-5177
• DOI: 10.1016/j.pbb.2020.172856

Over the last two decades, the discovery of ketamine's antidepressant properties has galvanized research into the neurobiology of treatment-resistant depression. Nevertheless, the mechanism of action underlying antidepressant response to ketamine remains unclear. This study reviews electrophysiological studies of ketamine's effects in individuals with depression as well as healthy controls, with a focus on two putative markers of synaptic potentiation: gamma oscillations and long-term potentiation. The review focuses on: 1) measures of gamma oscillations and power and their relationship to both acute, psychotomimetic drug effects as well as delayed antidepressant response in mood disorders; 2) changes in long-term potentiation as a promising measure of synaptic potentiation following ketamine administration; and 3) recent efforts to model antidepressant response to ketamine using novel computational modeling techniques, in particular the application of dynamic causal modeling to electrophysiological data. The latter promises to better characterize the mechanisms underlying ketamine's antidepressant effects. •Electrophysiological studies of ketamine's effects are reviewed.•Review includes ketamine response in depression and healthy subjects.•Markers of synaptic potentiation reviewed include gamma and long-term potentiation.•Dynamic causal modeling of ketamine response is discussed.