Skip to content

Kazutaka Ikeda

10 papers in the library · 130 citations · publishing 2011-2026

Papers

Sort Most recent Most cited

Development of Japanese Versions of the 4‐Item Mystical Experience Questionnaire and 7‐Item Challenging Experience Questionnaire

Neuropsychopharmacology Reports August 27, 2026 Futaba Umemura, Hiroko Kotajima‐Murakami, Justin C Strickland et al.

INTRODUCTION: Interest in therapeutic applications of psychedelics has recently resurged. Mystical-type and challenging experiences that are elicited by psychedelics are commonly assessed using the 30-item Mystical Experience Questionnaire (MEQ-30) and the 26-item Challenging Experience Questionnaire (CEQ), respectively. The brief 4-item MEQ (MEQ-4) and 7-item CEQ (CEQ-7) may reduce respondent...

Global Perspectives on CNS Drug Innovation: Achievements, Barriers, and Priorities for the Next Decade

The International Journal of Neuropsychopharmacology May 5, 2026 Hiroyuki Uchida, Gabriella Gobbi, Joseph Zohar et al.

BACKGROUND: Over the past decade, neuropsychopharmacology has shifted from stagnation to momentum, with first-in-class mechanisms and biomarker-enabled trials spanning psychiatry and neurology. METHODS: We narratively synthesized advances from 2013 to 2026 across central nervous system (CNS) discovery and development, including pivotal trials, regulatory actions, digital/real-world evidence,...

DOI: 10.1093/ijnp/pyag023 (opens in new tab) Neuropsychopharmacology Mandate Neuroactive steroid Clinical neuroscience +5

Effects of NMDA receptor antagonists on working memory and gamma oscillations, and the mediating role of the GluN2D subunit.

Neuropsychopharmacology May 15, 2025 Chitra Vinnakota, Matthew R Hudson, Kazutaka Ikeda et al. 6 citations

Working memory relies on synchronised network oscillations involving complex interplay between pyramidal cells and GABAergic interneurons. NMDA receptor (NMDAR) antagonists influence both network oscillations and working memory, but the relationship between these two consequences has not been elucidated. This study aimed to determine the effect of NMDAR antagonists on network oscillations...

DOI: 10.1038/s41386-025-02129-9 (opens in new tab) Full text (opens in new tab) Cognitive function Brain waves Memory research Neural receptors

Loss of the sustained antidepressant-like effect of (2R,6R)-hydroxynorketamine in NMDA receptor GluN2D subunit knockout mice.

Journal of Pharmacological Sciences March 1, 2024 Aimi Yamagishi, Yuiko Ikekubo, Masayoshi Mishina et al. 6 citations

Ketamine, an N-methyl-d-aspartate (NMDA) receptor antagonist, has attracted attention for its acute and sustained antidepressant effects in patients with depression. Hydroxynorketamine (HNK), a metabolite of ketamine, exerts antidepressant effects without exerting ketamine's side effects and has attracted much attention in recent years. However, the detailed pharmacological mechanism of action...

DOI: 10.1016/j.jphs.2024.01.008 (opens in new tab) Full text (opens in new tab) Glun2d Hydroxynorketamine Tail-suspension test Depression treatment +3

Understanding the role of the NMDA receptor subunit, GluN2D, in mediating NMDA receptor antagonist-induced behavioral disruptions in male and female mice.

Journal of Neuroscience Research 2024 Chitra Vinnakota, Anna Schroeder, Xin Du et al. 7 citations

Noncompetitive NMDA receptor (NMDAR) antagonists like phencyclidine (PCP) and ketamine cause psychosis-like symptoms in healthy humans, exacerbate schizophrenia symptoms in people with the disorder, and disrupt a range of schizophrenia-relevant behaviors in rodents, including hyperlocomotion. This is negated in mice lacking the GluN2D subunit of the NMDAR, suggesting the GluN2D subunit mediates...

Dual actions of 5‐MeO‐DIPT at the serotonin transporter and serotonin 5‐HT1A receptor in the mouse striatum and prefrontal cortex

Neuropsychopharmacology Reports February 6, 2021 Yoko Hagino, F. Scott Hall, George R. Uhl et al. 3 citations

Abstract Aims 5‐Methoxy‐ N , N ‐diisopropyltryptamine (5‐MeO‐DIPT) is a synthetic orally active hallucinogenic tryptamine analogue. The present study examined whether the effects of 5‐MeO‐DIPT involve the serotonin transporter (SERT) and serotonin 5‐hydroxytryptamine‐1A (5‐HT 1A ) receptor in the striatum and prefrontal cortex (PFC). Methods We investigated the effects of 5‐MeO‐DIPT on...

DOI: 10.1002/npr2.12161 (opens in new tab) Striatum 5-HT Receptor Serotonin transporter Dopamine +6

Role of NMDA receptor GluN2D subunit in the antidepressant effects and the cognitive impairment effects of enantiomers of ketamine

Proceedings for Annual Meeting of The Japanese Pharmacological Society 2018 Soichiro Ide, Yuiko Ikekubo, Masayoshi Mishina et al.

Background: The N-methyl-D-aspartate (NMDA) receptor antagonist ketamine exerts rapid and sustained antidepressant effects in depressed patients. Ketamine is a racemic mixture of equal amounts of enantiomers, (R)-ketamine and (S)-ketamine. The neural mechanisms that underlie different effects of these enantiomers remain unclear.

Role of NMDA receptor GluN2D subunit in the antidepressant effects of enantiomers of ketamine

Journal of Pharmacological Sciences November 1, 2017 Soichiro Ide, Yuiko Ikekubo, Masayoshi Mishina et al. 44 citations

We investigated the rapid and sustained antidepressant effects of enantiomers of ketamine in N-methyl-d-aspartate (NMDA) receptor GluN2D subunit knockout (GluN2D-KO) mice. Intraperitoneal administration of ketamine or its enantiomers 10 min before the tail-suspension test exerted significant antidepressant effects on restraint stress-induced depression in both wildtype and GluN2D-KO mice. The...

Effects of MDMA on Extracellular Dopamine and Serotonin Levels in Mice Lacking Dopamine and/or Serotonin Transporters

Current Neuropharmacology March 1, 2011 Yoko Hagino, Yukio Takamatsu, Hideko Yamamoto et al. 64 citations

3,4-Methylendioxymethamphetamine (MDMA) has both stimulatory and hallucinogenic properties which make its psychoactive effects unique and different from those of typical psychostimulant and hallucinogenic agents. The present study investigated the effects of MDMA on extracellular dopamine (DA(ex)) and serotonin (5-HT(ex)) levels in the striatum and prefrontal cortex (PFC) using in vivo...

DOI: 10.2174/157015911795017254 (opens in new tab) MDMA Serotonin transporter Dopamine transporter Pharmacology +2

Inhibition of g protein-activated inwardly rectifying k channels by phencyclidine.

Current Neuropharmacology March 2011 Toru Kobayashi, Daisuke Nishizawa, Kazutaka Ikeda

Addictive drugs, such as opioids, ethanol, cocaine, amphetamine, and phencyclidine (PCP), affect many functions of the nervous system and peripheral organs, resulting in severe health problems. G protein-activated inwardly rectifying K(+) (GIRK, Kir3) channels play an important role in regulating neuronal excitability through activation of various Gi/o protein-coupled receptors including opioid...

DOI: 10.2174/157015911795017407 (opens in new tab) Full text (opens in new tab) Girk channel Kir channel Phencyclidine Xenopus oocyte. +1