Skip to content

Kenji Hashimoto

Chiba University, Center for Forensic Mental Health, Chiba University

77 papers in the library · 4,709 citations · publishing 1990-2026

Papers

Sort Most recent Most cited

(R)-Ketamine Rapidly Ameliorates the Decreased Spine Density in the Medial Prefrontal Cortex and Hippocampus of Susceptible Mice After Chronic Social Defeat Stress

The International Journal of Neuropsychopharmacology August 28, 2019 Jiancheng Zhang, Youge Qu, Lijia Chang et al. 56 citations

BACKGROUND: A recent study demonstrated that spine formation rates by ketamine in the prefrontal cortex (PFC) were not altered at 3-6 h following a single injection, but were markedly altered at 12-24 h. Here, we investigated the acute (3 h post-treatment) effects of (R)-ketamine in the decreased spine density in the medial PFC (mPFC) and hippocampus in susceptible mice after chronic social...

Beneficial effects of (R)-ketamine, but not its metabolite (2R,6R)-hydroxynorketamine, in the depression-like phenotype, inflammatory bone markers, and bone mineral density in a chronic social defeat stress model.

Behavioural Brain Research August 1, 2019 Zhongwei Xiong, Yuko Fujita, Kai Zhang et al.

Inflammatory bone markers may play a role in the antidepressant actions of (R)-ketamine in susceptible mice after chronic social defeat stress (CSDS). In this study, we compared the effects of (R)-ketamine and its final metabolite (2R,6R)-hydroxynorketamine (HNK) in depression-like phenotypes, inflammatory bone markers and bone mineral density (BMD) in CSDS susceptible mice. We measured plasma...

(R)-Ketamine Induces a Greater Increase in Prefrontal 5-HT Release Than (S)-Ketamine and Ketamine Metabolites via an AMPA Receptor-Independent Mechanism

The International Journal of Neuropsychopharmacology July 16, 2019 Yukio Ago, Wataru Tanabe, Momoko Higuchi et al. 91 citations

BACKGROUND: Although recent studies provide insight into the molecular mechanisms of the effects of ketamine, the antidepressant mechanism of ketamine enantiomers and their metabolites is not fully understood. In view of the involvement of mechanisms other than the N-methyl-D-aspartate receptor in ketamine's action, we investigated the effects of (R)-ketamine, (S)-ketamine, (R)-norketamine...

Rapid‐acting antidepressant ketamine, its metabolites and other candidates: A historical overview and future perspective

Psychiatry and Clinical Neurosciences June 19, 2019 Kenji Hashimoto 325 citations

Major depressive disorder (MDD) is one of the most disabling psychiatric disorders. Approximately one‐third of the patients with MDD are treatment resistant to the current antidepressants. There is also a significant therapeutic time lag of weeks to months. Furthermore, depression in patients with bipolar disorder (BD) is typically poorly responsive to antidepressants. Therefore, there exists...

Comparison of antidepressant and side effects in mice after intranasal administration of (R,S)-ketamine, (R)-ketamine, and (S)-ketamine.

Pharmacology, Biochemistry and Behavior June 1, 2019 Lijia Chang, Kai Zhang, Yaoyu Pu et al. 174 citations

The N-methyl-d-aspartate receptor (NMDAR) antagonist (R,S)-ketamine produces rapid and sustained antidepressant effects in treatment-resistant patients with depression although intranasal use of (R,S)-ketamine in ketamine abusers is popular. In March 5, 2019, nasal spray of (S)-ketamine for treatment-resistant depression was approved as a new antidepressant by the US Food Drug Administration....

Role of Actinobacteria and Coriobacteriia in the antidepressant effects of ketamine in an inflammation model of depression

Pharmacology, Biochemistry and Behavior 2019 Nian-nian Huang, Dongyu Hua, Gaofeng Zhan et al.

ABSTRACT Ketamine, an N‐methyl‐d‐aspartic acid receptor (NMDAR) antagonist, elicits rapid‐acting and sustained antidepressant effects in treatment‐resistant depressed patients. Accumulating evidence suggests that gut microbiota via the gut‐brain axis play a role in the pathogenesis of depression, thereby contributing to the antidepressant actions of certain compounds. Here we investigated the...

An update on ketamine and its two enantiomers as rapid-acting antidepressants

Expert Review of Neurotherapeutics December 4, 2018 Kai Zhang, Kenji Hashimoto 133 citations

Introduction: Depression is one of the most disabling diseases worldwide. Approximately one-third of depressed patients are treatment-resistant to the currently available antidepressants and there is a significant therapeutic time lag of weeks to months. There is a clear unmet need for rapid-acting and more efficacious treatments. (R,S)-ketamine, an old anesthetic drug, appears now to be going...

Is (S)-norketamine an alternative antidepressant for esketamine?

European Archives of Psychiatry and Clinical Neuroscience July 14, 2018 Kenji Hashimoto, Chun Yang

The N-methyl-d-aspartate receptor (NMDAR) antagonist (R,S)ketamine has been hailed as the most important advance in the treatment of depression for the past 50 years. The rapid and sustained antidepressant effects of (R,S)-ketamine have spurred a great deal of research interest, with growing off-label use for the treatment of depression, although the concerns about the safety of repeated...

Mechanistic Target of Rapamycin-Independent Antidepressant Effects of (R)-Ketamine in a Social Defeat Stress Model.

Biological Psychiatry 2018 Chun Yang, Q. Ren, Y. Qu et al. 249 citations

BACKGROUND The role of the mechanistic target of rapamycin (mTOR) signaling in the antidepressant effects of ketamine is controversial. In addition to mTOR, extracellular signal-regulated kinase (ERK) is a key signaling molecule in prominent pathways that regulate protein synthesis. (R)-Ketamine has a greater potency and longer-lasting antidepressant effects than (S)-ketamine. Here we...

Possible role of the gut microbiota–brain axis in the antidepressant effects of (R)-ketamine in a social defeat stress model

Translational Psychiatry December 15, 2017 Chun Yang, Youge Qu, Yuko Fujita et al. 231 citations

Accumulating evidence suggests that the gut microbiota-brain axis plays a role in the pathogenesis of depression, thereby contributing to the antidepressant actions of certain compounds. (R)-ketamine has a greater potency and longer-lasting antidepressant effects than (S)-ketamine. Here, we investigated whether the gut microbiota plays a role in the antidepressant effects of these two ketamine...

Lack of Antidepressant Effects of (2R,6R)-Hydroxynorketamine in a Rat Learned Helplessness Model: Comparison with (R)-Ketamine

The International Journal of Neuropsychopharmacology November 14, 2017 Yukihiko Shirayama, Kenji Hashimoto 113 citations

Background: (R)-Ketamine exhibits rapid and sustained antidepressant effects in animal models of depression. It is stereoselectively metabolized to (R)-norketamine and subsequently to (2R,6R)-hydroxynorketamine in the liver. The metabolism of ketamine to hydroxynorketamine was recently demonstrated to be essential for ketamine's antidepressant actions. However, no study has compared the...

Comparison of (R)-ketamine and lanicemine on depression-like phenotype and abnormal composition of gut microbiota in a social defeat stress model

Scientific Reports November 10, 2017 Youge Qu, Chun Yang, Qian Ren et al. 126 citations

Accumulating evidence suggests a key role of the gut-microbiota-brain axis in the antidepressant actions of certain compounds. Ketamine, an N-methyl-D-aspartate receptor (NMDAR) antagonist, showed rapid and sustained antidepressant effects in treatment-resistant depressed patients. In contrast, another NMDAR antagonist, lanicemine, did not exhibit antidepressant effects in such patients....

Alterations in the inflammatory cytokines and brain-derived neurotrophic factor contribute to depression-like phenotype after spared nerve injury: improvement by ketamine

Scientific Reports June 5, 2017 Ze-Min Xie, Xingming Wang, Ning Xu et al. 69 citations

Although pain is frequently accompanied with depression, little is known about the risk factors contributing to individual differences to the comorbidity of pain and depression. In this study, we examined whether cytokines and brain-derived neurotrophic factor (BDNF) might contribute to the individual differences in the development of neuropathic pain-induced depression. Rats were randomly...

Rapid and Sustained Antidepressant Action of the mGlu2/3 Receptor Antagonist MGS0039 in the Social Defeat Stress Model: Comparison with Ketamine

The International Journal of Neuropsychopharmacology October 7, 2016 Chao Dong, Ji-Chun Zhang, Wei Yao et al. 116 citations

Background: Similar to the N-methyl-D-aspartate receptor antagonist ketamine, the metabotropic glutamate 2/3 receptor antagonist, MGS0039, shows antidepressant effects. However, there are no reports comparing these 2 compounds in the social defeat stress model of depression. Methods: We examined the effects of MGS0039 (1 mg/kg) and ketamine (10 mg/kg) on depression-like behavior in susceptible...

Ketamine’s antidepressant action: beyond NMDA receptor inhibition

Expert Opinion on Therapeutic Targets September 20, 2016 Kenji Hashimoto 68 citations

The N-methyl-D-aspartate (NMDA) receptor antagonist ketamine is one of the most attractive antidepressants since this drug causes rapid-onset and sustained antidepressant effects in treatment resistant patients with depression. There are unanswered questions about how ketamine induces its rapid and sustained antidepressant actions. This key article suggests that (2R,6R)-HNK...

Comparison of R-ketamine and rapastinel antidepressant effects in the social defeat stress model of depression

Psychopharmacology August 3, 2016 Bangkun Yang, Ji-Chun Zhang, Mei Han et al. 93 citations

RATIONALE: The N-methyl-D-aspartate (NMDA) receptor antagonists, including R-ketamine and rapastinel (formerly GLYX-13), show rapid antidepressant effects in animal models of depression. OBJECTIVE: We compared the rapid and sustained antidepressant effects of R-ketamine and rapastinel in the social defeat stress model. RESULTS: In the tail suspension and forced swimming tests, R-ketamine (10...

Reduction of dopamine D2/3 receptor binding in the striatum after a single administration of esketamine, but not R-ketamine: a PET study in conscious monkeys

European Archives of Psychiatry and Clinical Neuroscience April 18, 2016 Kenji Hashimoto, Takeharu Kakiuchi, Hiroyuki Ohba et al. 125 citations

R-ketamine appears to be a potent, long-lasting and safer antidepressant, relative to esketamine (S-ketamine), since it might be free of psychotomimetic side effects. Using [11C]raclopride and positron emission tomography (PET), we investigated whether esketamine and R-ketamine can affect dopamine D2/3 receptor binding in the conscious monkey brain. A single infusion of esketamine (0.5 mg/kg),...

Role of hippocampal p11 in the sustained antidepressant effect of ketamine in the chronic unpredictable mild stress model

Translational Psychiatry February 23, 2016 H-L Sun, Z-Q Zhou, G.-F. Zhang et al. 87 citations

Although ketamine shows a rapid and sustained antidepressant effect, the precise mechanisms underlying its effect are unknown. Recent studies indicate a key role of p11 (also known as S100A10) in depression-like behavior in rodents. The present study aimed to investigate the role of p11 in the antidepressant-like action of ketamine in chronic unpredictable mild stress (CUMS) rat model. The...

R-ketamine: a rapid-onset and sustained antidepressant without psychotomimetic side effects

Translational Psychiatry September 1, 2015 Chun Yang, Yukihiko Shirayama, J-C Zhang et al. 600 citations

Although the efficacy of racemate ketamine, a rapid onset and sustained antidepressant, for patients with treatment-resistant depression was a serendipitous finding, clinical use of ketamine is limited, due to psychotomimetic side effects and abuse liability. Behavioral and side-effect evaluation tests were applied to compare the two stereoisomers of ketamine. To elucidate their potential...

Glutamate Signaling in Synaptogenesis and NMDA Receptors as Potential Therapeutic Targets for Psychiatric Disorders

Current Molecular Medicine May 4, 2015 Yuta Ohgi, Takashi Futamura, Kenji Hashimoto 109 citations

Glutamate, a major excitatory neurotransmitter, plays important roles in synaptic plasticity, such as long-term potentiation (LTP) and new synapse formation. Growing evidence suggests that glutamate signaling is involved in the neurobiology of psychiatric disorders, including schizophrenia, major depressive disorder (MDD) and bipolar disorder (BP). Postmortem brain studies demonstrated altered...

Combination of Nitrous Oxide with Isoflurane or Scopolamine for Treatment-resistant Major Depression

Clinical Psychopharmacology and Neuroscience April 1, 2015 Chun Yang, Kenji Hashimoto

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Combination of Nitrous Oxide with Isoflurane or Scopolamine for Treatment-resistant Major...

Long-Lasting Antidepressant Action of Ketamine, but Not Glycogen Synthase Kinase-3 Inhibitor SB216763, in the Chronic Mild Stress Model of Mice

PLoS One February 4, 2013 Xiancang Ma, Yonghui Dang, Min Jia et al. 115 citations

BACKGROUND: Clinical studies demonstrate that the N-methyl-D-aspartate (NMDA) receptor antagonist, ketamine, induces rapid antidepressant effects in patients with refractive major depressive disorder and bipolar depression. This rapid onset of action makes ketamine a highly attractive drug for patients, particularly those who do not typically respond to therapy. A recent study suggested that...

The role of glutamate on the action of antidepressants.

Progress in neuro-psychopharmacology & biological psychiatry August 15, 2011 Kenji Hashimoto

Major depressive disorder (MDD) is a common, chronic, recurrent mental illness that affects millions of individuals worldwide. Currently available antidepressants are known to affect the monoaminergic (e.g., serotonin, norepinephrine, and dopamine) systems in the brain. Accumulating evidence suggests that the glutamatergic neurotransmission via the excitatory amino acid glutamate also plays an...

Combined intoxication with methylone and 5-MeO-MIPT

Progress in Neuro-psychopharmacology and Biological Psychiatry July 30, 2006 Eiji Shimizu, Hiroyuki Watanabe, Takashi Kojima et al. 103 citations

Although preclinical studies suggest that methylone (2-methylamino-1-[3,4-methylenedioxyphenyl]propan-1-one) and 5-MeO-MIPT (5-methoxy-N-methyl,N-isopropyl tryptamine) may have psychostimulant properties, the scientific reports about the clinical effects of these agents are scant. We describe a 27-year-old male patient with substance intoxication after a single ingestion of the mixture of...

Reduction of in vivo binding of [3H]paroxetine in mouse brain by 3,4-methylenedioxymethamphetamine.

Neuropharmacology July 1990 Kenji Hashimoto, Tsuyoshi Goromaru

The effects of 3,4-methylenedioxymethamphetamine (MDMA) on the in vivo binding of [3H]paroxetine, a potent and selective 5-hydroxytryptamine (5-HT; serotonin) uptake inhibitor, in the brain of the mouse were studied. The distribution of radioactivity in the brain of the mouse, after intravenous administration of [3H]paroxetine, was significantly altered by pretreatment with MDMA (15 mg/kg,...