GluN2B‐containing NMDA Receptors on Sst‐interneurons act as Initial Cellular Trigger for Antidepressant Actions of Ketamine
Santosh Pothula, Rongjian Liu, Min Wu, Alexa‐Nicole Sliby, Ralph Dileone, Ronald S. Duman
The FASEB Journal May 1, 2021 DOI: 10.1096/fasebj.2021.35.s1.02392 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Preclinical experimental study Peer reviewed |
|---|---|
| Population | Male and female GluN2B fl/fl (WT) and Sst-cre GluN2Bfl/fl (KO) mice |
| Intervention | Ketamine |
| Dose | subanesthetic dose |
| Topics | Esketamine Ketamine |
| Keywords | Disinhibition Neurotransmission Inhibitory postsynaptic potential Excitatory postsynaptic potential Prefrontal cortex Nmda receptor Ampa receptor Hippocampal formation Interneuron Glutamate receptor |
| Key findings | Ketamine's antidepressant-like effects require GluN2B-NMDARs on Sst-interneurons, which mediate disinhibition of pyramidal neurons, activation of mTOR signaling, and reversal of stress-induced behavioral deficits. |
Abstract
A single subanesthetic dose of ketamine exerts rapid antidepressant‐like effects via rapid glutamate efflux, activation of mTORC1 signaling, and enhanced synaptic transmission in the medial prefrontal cortex (mPFC); however, the initial cellular trigger for these synaptic and behavioral actions of ketamine still remains unclear. Here, we used electrophysiology, biochemistry, molecular biology and behavioral approaches to determine the baseline sex differences in behavior after GluN2B conditional deletion from Sst‐interneurons, and effect of ketamine on chronic unpredictable stress (CUS)‐induced behavioral deficits, activation of mTOR signaling cascade and changes in synaptic transmission in male and female GluN2B fl/fl (WT) and Sst‐cre GluN2Bfl/fl mice (KO) mice. Acute treatment of ketamine reduces NMDA‐induced burst firing of Sst‐interneurons ex vivo in mPFC. Deletion of GluN2B from Sst‐GABAergic interneurons in the KO produced sexually dimorphic changes in synaptic transmission and behavior. Consistent with the disinhibition hypothesis, ketamine reduces inhibitory, but enhances excitatory transmission of layer V pyramidal neurons of mPFC and reverses CUS‐induced behavioral deficits only in WT, but not KO, mice. Preliminary data demonstrate that deletion of GluN2B from Sst‐interneurons blocks ketamine‐induced activation of mTOR signaling cascade. Our results demonstrate that Sst‐interneurons are an initial cellular trigger for synaptic and behavioral actions of ketamine. Consistent with the disinhibition hypothesis, ketamine actions are mediated by GluN2B‐NMDARs on Sst‐interneurons via disinhibition of pyramidal neurons, activation of mTOR signaling, and enhanced synaptic function in mPFC.
Comparable studies
Other preclinical and animal studies on ketamine, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| mTOR-Dependent Synapse Formation Underlies the Rapid Antidepressant Effects of NMDA Antagonists Rats | 2010 | Observational study | |
| Activation of Glutamatergic Neurotransmission by Ketamine: A Novel Step in the Pathway from NMDA Receptor Blockade to Dopaminergic and Cognitive Disruptions Associated with the Prefrontal Cortex Conscious rats | 1997 | Dose-response study with microdialysis and behavioral testing | |
| NMDAR inhibition-independent antidepressant actions of ketamine metabolites Mice | 2016 | Preclinical study | |
| The dissociative anaesthetics, ketamine and phencyclidine, selectively reduce excitation of central mammalian neurones by N‐methyl‐aspartate Spinal neurons in decerebrate or pentobarbitone-anaesthetized cats and rats | 1983 | Experimental study | |
| R-ketamine: a rapid-onset and sustained antidepressant without psychotomimetic side effects Mice | 2015 | Experimental study |