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Nitrous Oxide, a Rapid Antidepressant, Has Ketamine-like Effects on Excitatory Transmission in the Adult Hippocampus.
Izumi, Yukitoshi; Hsu, Fong-Fu; Conway, Charles R; Nagele, Peter; Mennerick, Steven J; Zorumski, Charles F.
Afiliação
  • Izumi Y; Department of Psychiatry and Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri; Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, Missouri.
  • Hsu FF; Department of Medicine and Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, St. Louis, Missouri.
  • Conway CR; Department of Psychiatry and Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri; Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, Missouri.
  • Nagele P; Department of Anesthesia and Critical Care, University of Chicago, Chicago, Illinois.
  • Mennerick SJ; Department of Psychiatry and Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri; Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, Missouri.
  • Zorumski CF; Department of Psychiatry and Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri; Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, Missouri. Electronic address: zorumskc@wustl.edu.
Biol Psychiatry ; 92(12): 964-972, 2022 12 15.
Article em En | MEDLINE | ID: mdl-36050137
ABSTRACT

BACKGROUND:

Nitrous oxide (N2O) is a noncompetitive inhibitor of NMDA receptors that appears to have ketamine-like rapid antidepressant effects in patients with treatment-resistant major depression. In preclinical studies, ketamine enhances glutamate-mediated synaptic transmission in the hippocampus and prefrontal cortex. In this study, we examined the effects of N2O on glutamate transmission in the hippocampus and compared its effects to those of ketamine.

METHODS:

Glutamate-mediated synaptic transmission was studied in the CA1 region of hippocampal slices from adult albino rats using standard extracellular recording methods. Effects of N2O and ketamine at subanesthetic concentrations were evaluated by acute administration.

RESULTS:

Akin to 1 µM ketamine, 30% N2O administered for 15-20 minutes resulted in persistent enhancement of synaptic responses mediated by both AMPA receptors and NMDA receptors. Synaptic enhancement by both N2O and ketamine was blocked by co-administration of a competitive NMDA receptor antagonist at saturating concentration, but only ketamine was blocked by an AMPA receptor antagonist. Synaptic enhancement by both agents involved TrkB (tropomyosin receptor kinase B), mTOR (mechanistic target of rapamycin), and NOS (nitric oxide synthase) with some differences between N2O and ketamine. N2O potentiation occluded enhancement by ketamine, and in vivo N2O exposure occluded further potentiation by both N2O and ketamine.

CONCLUSIONS:

These results indicate that N2O has ketamine-like effects on hippocampal synaptic function at a subanesthetic, but therapeutically relevant concentration. These 2 rapid antidepressants have similar, but not identical mechanisms that result in persisting synaptic enhancement, possibly contributing to psychotropic actions.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Ketamina Limite: Animals Idioma: En Revista: Biol Psychiatry Ano de publicação: 2022 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Ketamina Limite: Animals Idioma: En Revista: Biol Psychiatry Ano de publicação: 2022 Tipo de documento: Article