Cited by 198Treatment of Major DepressionNeuroscience and Neuropharmacology ResearchTryptophan and brain disorders

Transiently increased glutamate cycling in rat PFC is associated with rapid onset of antidepressant-like effects

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Chowdhury, G M I, Zhang, J, Thomas, M, Banasr, M, Ma, X, Pittman, B, Bristow, L, Schaeffer, E +4 more·2017·Molecular Psychiatry

Abstract

Several drugs have recently been reported to induce rapid antidepressant effects in clinical trials and rodent models. Although the cellular mechanisms involved remain unclear, reports suggest that increased glutamate transmission contributes to these effects. Here, we demonstrate that the antidepressant-like efficacy of three unique drugs, with reported rapid onset antidepressant properties, is coupled with a rapid transient rise in glutamate cycling in the medial prefronal cortex (mPFC) of awake rats as measured by ex vivo 1 H-[13 C]-nuclear magnetic resonance spectroscopy. Rats were acutely pretreated by intraperitoneal injection with a single dose of ketamine (1, 3, 10, 30 and 80 mg kg-1), Ro 25-6981 (1, 3 and 10 mg kg-1), scopolamine (5, 25 and 100 μg kg-1) or vehicle (controls). At fixed times after drug injection, animals received an intravenous infusion of [1,6-13 C 2]glucose for 8 min to enrich the amino-acid pools of the brain with 13 C, followed by rapid euthanasia. The mPFC was dissected, extracted with ethanol and metabolite 13 C enrichments were measured. We found a clear dose-dependent effect of ketamine and Ro 25-6981 on behavior and the percentage of 13 C enrichment of glutamate, glutamine and GABA (γ-aminobutyric acid). Further, we also found an effect of scopolamine on both cycling and behavior. These studies demonstrate that three pharmacologically distinct classes of drugs, clinically related through their reported rapid antidepressant actions, share the common ability to rapidly stimulate glutamate cycling at doses pertinent for their antidepressant-like efficacy. We conclude that increased cycling precedes the antidepressant action at behaviorally effective doses and suggest that the rapid change in cycling could be used to predict efficacy of novel agents or identify doses with antidepressant activity.

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Crossref · 10.1038/mp.2016.34

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  • Rodent studies have shown that ketamine and other NMDA receptor antagonists transiently increase measures reflecting glutamate-glutamine cycling and glutamate neurotransmission in the frontal cortex.

    “Rodent studies employing carbon-13 magnetic resonance spectroscopy ( 13 C MRS) methods have shown ketamine and other N-methyl-D-aspartate (NMDA) receptor antagonists to transiently increase measures reflecting glutamate-glutamine cycling and glutamate neurotransmission in the frontal cortex.”

    From The effects of ketamine on prefrontal glutamate neurotransmission in healthy and depressed subjects (2018) · cites this paper as [17]

    The Results and Discussion report that carbon-13 NMR measures of glutamate–glutamine cycling increased in rat medial prefrontal cortex after ketamine and the NMDA receptor antagonist Ro 25-6981. The Discussion establishes that ketamine’s effect was transient, but explicitly says Ro 25-6981’s time course was not examined, so the source does not establish that its increase was transient. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • By 18 min after injection, both prefrontal 13C glutamate (~13%) and glutamine (~35%) enrichment increased in rodents.

    “By 18 min after the injection, both prefrontal 13 C glutamate (~13%) and glutamine (~35%) enrichment increased [17].”

    From The effects of ketamine on prefrontal glutamate neurotransmission in healthy and depressed subjects (2018) · cites this paper as [17]

    The Results section on time dependence reports that, following ketamine injection in rats, both mPFC glutamate-C4 and glutamine-C4 13C labeling increased during the 10–18-minute interval. Our copy does not give the claimed ~13% and ~35% increases for that interval; a separate dose-response result reports 9% and 38%, respectively. Page numbers are unavailable in our copy. (LLM, conf=0.85)

    Experimental — accuracy not yet measured
  • In rodents, approximately 9 min after intraperitoneal injection, ketamine induces a rise in prefrontal 13C glutamine enrichment (~20%) with no changes in 13C glutamate (~1%).

    “In particular, approximately 9 min after intraperitoneal injection in rodents, ketamine induces a rise in prefrontal 13 C glutamine enrichment (~20%) with no changes in 13 C glutamate (~1%) [17]”

    From The effects of ketamine on prefrontal glutamate neurotransmission in healthy and depressed subjects (2018) · cites this paper as [17]

    The Results (time-dependence section; page unavailable) report increased prefrontal 13C glutamine enrichment during the first 0.5–8.5 minutes after intraperitoneal ketamine in rats; 13C glutamate increased significantly only during the later 10–18-minute interval. This supports the early glutamine rise and lack of a significant early glutamate change, but our copy does not state the claimed approximate 20% and 1% values. (LLM, conf=0.86)

    Experimental — accuracy not yet measured
  • The changes in 13C-glutamine (13%) were more prominent than 13C-glutamate (1%), comparable to preclinical findings.

    “Comparable to preclinical findings with 13 C MRS [17], the changes in 13 C-glutamine (13%) were more prominent than 13 C-glutamate (1%).”
  • Preclinical 13C MRS data suggest disproportionate changes following ketamine administration.

    “While these processes are highly coupled under normal conditions, preclinical 13 C MRS data suggest disproportionate changes following ketamine administration [16,17].”

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Authors
Chowdhury, G. M. I., Zhang, J., Thomas, M., Banasr, M., Ma, X., Pittman, B., Bristow, L., Schaeffer, E., Duman, R. S., Rothman, D. L., Behar, K. L., & Sanacora, G.
Affiliations
  • Yale University (US)
  • Centre for Addiction and Mental Health (CA)
  • Bristol-Myers Squibb (United States) (US)
Corresponding author
  • Chowdhury, G M I
  • Sanacora, G
Venue
Molecular Psychiatry
Published
2016-04-12
Volume
22
Issue
1
Pages
120-126
ISSN
  • 1359-4184 (ISSN-L)
  • 1476-5578
OpenAlex
W2336977282
Cited by
197
References
36
Citations by year
2026: 4 · 2025: 20 · 2024: 16 · 2023: 15 · 2022: 22 · 2021: 23 · 2020: 22 · 2019: 24 · 2018: 26 · 2017: 19 · 2016: 5 · 2013: 1
FWCI
19.97
Type
journal article
Language
en
Open access
Locations
  • Molecular Psychiatry (publishedVersion)
  • PubMed (publishedVersion)
  • Europe PMC (PubMed Central) (acceptedVersion)
  • PubMed Central (acceptedVersion)
Funders
  • Bristol-Myers Squibb
  • Servier
  • National Institutes of Health (1r01mh095104-01)
  • National Center for PTSD, U.S. Department of Veterans Affairs
  • National Institute of Mental Health (R01MH081211, R01-MH095104, R01MH105910)
  • National Institute of Neurological Disorders and Stroke (P30NS052519)
Topics
  • Health Sciences › Medicine › Pharmacology › Treatment of Major Depression
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neuroscience and Neuropharmacology Research
  • Life Sciences › Neuroscience › Biological Psychiatry › Tryptophan and brain disorders
Keywords
rapid-acting antidepressants, medial prefrontal cortex, ketamine, Ro 25-6981, scopolamine, glutamate, glutamine, GABA, 13C metabolic labeling, antidepressant-like behavior
MeSH terms
Animals, Antidepressive Agents, Brain, gamma-Aminobutyric Acid, Glutamine, Ketamine, Male, Magnetic Resonance Spectroscopy, Phenols, Piperidines, Scopolamine, Rats, Sprague-Dawley, Prefrontal Cortex, Glutamic Acid, Rats

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