Background: Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, is widely used as a general anaesthetic. However, the mechanisms of analgesic/anaesthetic effects induced by ketamine are only partially understood. Previously, studies have demonstrated that various general anaesthetics affect the primary somatosensory cortex (S1), a potential target of general anaesthetics in the central nervous system. However, it is unknown if astrocyte activities affect ketamine's effects on information transmission in S1 pyramidal neurons.
Methods: The whole-cell patch-clamp technique was employed to study the role of astrocytes in ketamine-induced anaesthetic actions. The whole-cell patch-clamp method was used to record the spontaneous postsynaptic currents (SPSCs) of rat S1 pyramidal neurons. We used the glia-selective inhibitor of the aconitase enzyme fluorocitrate (FC), to test if astrocyte activities alter the effects of ketamine on S1 pyramidal neurons.
Results: Ketamine lowered the SPSCs of rat S1 pyramidal neurons in a concentration-dependent manner at clinically relevant doses. The concentration-effect curve revealed that ketamine had an EC50 value of 462.1 M for suppressing SPSCs. In rat S1 pyramidal neurons, the glia-selective metabolic inhibitor fluorocitrate (FC), which inhibits the aconitase enzyme, lowered the amplitude and frequency of SPSCs. The inhibitory impact of ketamine on the amplitude and frequency of SPSCs was significantly amplified in the presence of FC.
Conclusions: Astrocytes impact the effects of ketamine on pre- and postsynaptic components and play a role in synaptic transmission.
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http://dx.doi.org/10.31083/j.jin2205116 | DOI Listing |
Expert Rev Clin Pharmacol
January 2025
Department of Psychiatry, McGill University, Montréal, Canada.
Introduction: Since its synthesis in 1962, ketamine has been widely used in diverse medical contexts, from anesthesia to treatment-resistant depression. However, interpretations of ketamine's subjective effects remain polarized. Biomedical frameworks typically construe the drug's experiential effects as dissociative or psychotomimetic, while psychedelic paradigms emphasize the potential therapeutic merits of these non-ordinary states.
View Article and Find Full Text PDFBJA Open
March 2025
Centre for Trauma Sciences, Blizard Institute, Queen Mary University of London, London, UK.
Background: Literature on prehospital anaesthesia predominantly focuses on preparation and induction, while there is limited guidance on anaesthesia maintenance. The hypothesis of this study was that for prehospital trauma patients, protocols and practice for anaesthesia maintenance may vary considerably between services. Hence, we sought to describe the practice of prehospital anaesthesia maintenance for trauma patients in Australia, New Zealand, and the UK.
View Article and Find Full Text PDFDrug Des Devel Ther
January 2025
Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, Beijing, People's Republic of China.
Purpose: This study aimed to assess the protective effect of a clinical dose esketamine on cerebral ischemia/reperfusion (I/R) injury and to reveal the potential mechanisms associated with microglial polarization and autophagy.
Methods: Experimental cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) in adult rats and simulated by oxygen-glucose deprivation (OGD) in BV-2 microglial cells. Neurological and sensorimotor function, cerebral infarct volume, histopathological changes, mitochondrial morphological changes, and apoptosis of ischemic brain tissues were assessed in the presence or absence of esketamine and the autophagy inducer rapamycin.
Drug Des Devel Ther
January 2025
Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, Fujian, People's Republic of China.
Purpose: While esketamine shows promise as an adjunct in procedural sedation, its impact on postoperative cognitive recovery remains incompletely characterized. This study investigated the effects of esketamine on multiple dimensions of recovery, particularly cognition, in patients undergoing colonoscopy with propofol-based sedation.
Patients And Methods: We conducted this randomized, double-blinded, placebo-controlled trial from January 6, 2023, to May 20, 2024, at two hospitals in China.
J Pain Res
January 2025
Department of Pediatrics- Division of Pediatric Oncology, Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, USA.
Introduction: Anti-GD2 immunotherapy has improved outcomes for children with high-risk neuroblastoma (HRNBL). Dinutuximab promotes complement-mediated reaction against disialoganglioside GD2, which is expressed in peripheral nerves and over-expressed in neuroblastoma. Dinutuximab is associated with ≥grade 3 neuropathic pain.
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