Impaired glutamate reuptake induces synaptic mistuning in rat hippocampal slices, that can be counteracted by ketamine
Erika Vazquez Juarez, Ipsit Srivastava, Maria Lindskog
bioRxiv Preprint Server January 25, 2022 preprint DOI: 10.1101/2022.01.25.477658 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental study |
|---|---|
| Population | Rat hippocampal slices and a rat model of depression |
| Interventions | DL-TBOA ketamine |
| Topics | Ketamine Neuroplasticity Esketamine |
| Keywords | Psychiatric disorders Mental health Neurological disorders Brain disorders Neuropsychiatric conditions Neurotransmission Synaptic function Brain signals Neural communication Long-term potentiation Glutamate Antidepressant Therapeutic Drug treatment Psychiatric medication Brain circuits Neural networks Brain function Circuit rebalancing Neural circuits |
| Citations | 1 |
| Key findings | Ketamine counteracts the effects of increased glutamate on synaptic retuning, suggesting its antidepressant mechanism is restoring adequate synaptic tuning. |
Abstract
Mistuning of synaptic transmission has been proposed to underlie many psychiatric disorders, with decreased reuptake of the excitatory neurotransmitter glutamate as one contributing factor. Synaptic tuning occurs through several diverging and converging forms of plasticity. By recording evoked field postsynaptic potentials in the CA1 area in hippocampal slices, we found that inhibiting glutamate transporters using DL-TBOA causes retuning of synaptic transmission, resulting in a new steady state with reduced synaptic strength and a lower threshold for inducing long-term synaptic potentiation (LTP). Moreover, we also found reduced threshold for LTP in a rat model of depression that has decreased levels of glutamate transporters. Most importantly, we found that the antidepressant ketamine counteracts the effects of increased glutamate on the various steps involved in synaptic retuning. We therefore propose that ketamine’s mechanism of action as an antidepressant is to restore adequate synaptic tuning.
Comparable studies
Other experimental studies on ketamine, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Ketamine activates psychosis and alters limbic blood flow in schizophrenia Schizophrenic individuals | 1995 | Experimental study | |
| The spectral exponent of the resting EEG indexes the presence of consciousness during unresponsiveness induced by propofol, xenon, and ketamine Healthy participants | 2019 | Controlled experimental study | n = 15 |
| Ketamine Increases Human Motor Cortex Excitability to Transcranial Magnetic Stimulation Normal human subjects | 2003 | Experimental study | n = 7 |
| Evidence that Subanesthetic Doses of Ketamine Cause Sustained Disruptions of NMDA and AMPA-Mediated Frontoparietal Connectivity in Humans Human participants | 2015 | Experimental study | |
| Simultaneous population pharmacokinetic modelling of ketamine and three major metabolites in patients with treatment‐resistant bipolar depression Patients with treatment-resistant bipolar depression | 2012 | Population pharmacokinetic analysis | n = 9 |
Citations in the library
Cites 7
- A Randomized Trial of an N-methyl-D-aspartate Antagonist in Treatment-Resistant Major Depression Archives of General Psychiatry August 1, 2006
- Mechanisms of Ketamine Action as an Antidepressant Molecular Psychiatry March 13, 2018
- Ketamine and Rapid-Acting Antidepressants: A Window into a New Neurobiology for Mood Disorder Therapeutics Annual Review of Medicine October 23, 2014
- Molecular mechanisms underlying the antidepressant actions of arketamine: beyond the NMDA receptor Molecular Psychiatry May 7, 2021
- Sustained rescue of prefrontal circuit dysfunction by antidepressant-induced spine formation Science April 12, 2019
and 2 more in the library