Ketamine's antidepressant effects have been linked to its modulation of glutamatergic neurotransmission and synaptic plasticity. However, the precise roles of both glutamate (Glu) levels and brain-derived neurotrophic factor (BDNF) in this process remain incompletely understood. This study examined the relationship between ketamine-induced changes in Glu levels and peripheral BDNF levels using...
The current systematic review and meta-analysis examined the effect of racemic ketamine or esketamine on suicidal ideation in individuals with uni- or bipolar depression. We searched the MEDLINE, Embase, Central, PsycINFO, and Web of Science databases to identify randomized controlled trials that examined the effect of racemic ketamine or esketamine monotherapy on suicidal ideation (SI) in...
The NMDA antagonist S-ketamine is gaining increasing use as a rapid-acting antidepressant, although its exact mechanisms of action are still unknown. In this study, we investigated ketamine in respect to its properties toward central noradrenergic mechanisms and how they influence alertness behavior. We investigated the influence of S-ketamine on the locus coeruleus (LC) brain network in a...
Subanesthetic doses of ketamine induce an antidepressant effect within hours in individuals with treatment-resistant depression while it furthermore induces immediate but transient psychotomimetic effects. Among these psychotomimetic effects, an altered sense of self has specifically been associated with the antidepressant response to ketamine as well as psychedelics. However, there is plenty...
Ketamine is a rapid-acting antidepressant that also influences neural reactivity to affective stimuli. However, the effect of ketamine on behavioral affective reactivity is yet to be elucidated. The affect-modulated startle reflex paradigm (AMSR) allows examining the valence-specific aspects of behavioral affective reactivity. We hypothesized that ketamine alters the modulation of the startle...
Abstract Ketamine shows rapid antidepressant effects peaking 24 h after administration. The antidepressant effects may occur through changes in glutamatergic metabolite levels and resting-state functional connectivity (rsFC) within the default mode network (DMN). A multistage drug effect of ketamine has been suggested, inducing acute effects on dysfunctional network configuration and delayed...
Any macrosystem consists of many microparticles. According to statistical physics, the macroproperties of a system are realized as the statistical average of the corresponding microproperties. In our study, a model based on ensemble theory from statistical physics is proposed. Specifically, the functional connectivity (FC) patterns confirmed by Leading Eigenvector Dynamics Analysis (LEiDA) are...
Increasing neuroimaging evidence suggests that mindfulness meditation expertise is related to different functional and structural configurations of the default mode network (DMN), the salience network (SN) and the executive network at rest. However, longitudinal studies observing resting network plasticity effects in brains of novices who started to practice meditation are scarce and generally...
Ketamine is a drug that reduces depressive and elicits schizophrenia-like symptoms in humans. However, it is largely unexplored whether women and men differ with respect to ketamine-action and whether age contributes to drug-effects. In this study we assessed dissociative symptoms via the Clinician Administered Dissociative States Scale (CADSS) in a total of 69 healthy subjects aged between 18...
Ketamine acts as a rapid-acting antidepressant by restoring glutamatergic deficits and activating synaptic plasticity processes, with peak activity 24 h after infusion. Microtubule dynamics are known to play a key role in modulation of cytoskeleton and synaptic plasticity, as well as in signalling events in peripheral blood cells. Here, we correlated ketamine-induced change in...
Recently, ketamine has been investigated as a potential antidepressant option for treatment resistant depression. Unlike traditional drugs, it yields immediate effects, most likely via increased glutamatergic transmission and synaptic plasticity. However, ketamine administration in humans is systemic and its long-term impact on blood parameters has not yet been described in clinical studies....
Ketamine is receiving increasing attention as a rapid-onset antidepressant in patients suffering from major depressive disorder (MDD) with treatment resistance or severe suicidal ideation. Ketamine modulates several neurotransmitter systems, including norepinephrine via the norepinephrine transporter (NET), both peripherally and centrally. The locus coeruleus (LC), which has high NET...
PLoS OneOctober 26, 2017Grace E. Fox, Meng Li, Fang Zhao et al.
Ketamine is known to induce psychotic-like symptoms, including delirium and visual hallucinations. It also causes neuronal damage and cell death in the retrosplenial cortex (RSC), an area that is thought to be a part of high visual cortical pathways and at least partially responsible for ketamine’s psychotomimetic activities. However, the basic physiological properties of RSC cells as well as...
Along with its rapid therapeutic benefits, ketamine induces transient experience of dissociation during administration. Given the suggested association between ketamine-induced dissociation and treatment response, understanding the neural correlates of dissociation would help to elucidate its therapeutic mechanism. The posteromedial cortex (PMC) has been reported to play a vital role in the...