The microbiota-gut-brain axis in hippocampus-dependent learning and memory: current state and future challenges

Neuroscience & Biobehavioral Reviews, Journal Year: 2023, Volume and Issue: 152, P. 105296 - 105296

Published: June 26, 2023

A fundamental shift in neuroscience suggests bidirectional interaction of gut microbiota with the healthy and dysfunctional brain. This microbiota-gut-brain axis has mainly been investigated stress-related psychopathology (e.g. depression, anxiety). The hippocampus, a key structure both brain these psychopathologies, is implicated by work rodents that substantially impact hippocampal-dependent learning memory. However, understanding microbiota-hippocampus mechanisms health disease, translation to humans, hampered absence coherent evaluative approach. We review current knowledge regarding four main routes rodents: through vagus nerve; via hypothalamus-pituitary-adrenal-axis; metabolism neuroactive substances; modulation host inflammation. Next, we suggest an approach including testing (biomarkers of) as function influence (composition) on (dys)functioning. argue such necessary proceed from state preclinical research beneficial application humans optimise microbiota-based strategies treat enhance memory (dys)functions.

Language: Английский

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Transcutaneous vagus nerve stimulation: a new strategy for Alzheimer’s disease intervention through the brain-gut-microbiota axis?

Frontiers in Aging Neuroscience, Journal Year: 2024, Volume and Issue: 16

Published: Feb. 27, 2024

Transcutaneous vagus nerve stimulation (tVNS) is an emerging non-invasive technique designed to stimulate branches of the distributed over body surface. Studies suggest a correlation between brain-gut-microbiota (BGM) axis and pathogenesis Alzheimer’s disease (AD). The BGM represents complex bidirectional communication system, with being crucial component. Therefore, electrical might have potential modify—most time probably in non-physiological way—the signal transmission within axis, potentially influencing progression or symptoms AD. This review explores interaction percutaneous emphasizing its effects on It examines various aspects, such as specific brain regions, gut microbiota composition, maintenance intestinal environmental homeostasis, inflammatory responses, plasticity, hypothalamic–pituitary–adrenal (HPA) regulation. suggests that tVNS could serve effective strategy modulate intervene treatment future.

Language: Английский

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Neurostimulation devices to treat Alzheimer’s disease

Exploration of neuroscience, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 25, 2025

The use of neurostimulation devices for the treatment Alzheimer’s disease (AD) is a growing field. In this review, we examine mechanism action and therapeutic indications these in AD process. Rapid advancements technologies are providing non-pharmacological relief to patients affected by pathology. Neurostimulation therapies include electrical stimulation that targets circuitry-level connection important brain areas such as hippocampus induce neuromodulation dysfunctional neural circuitry electromagnetic field (EMF) anti-amyloid molecular pathways promote degradation beta-amyloid (Aβ). These target specific or diffuse cortical subcortical modulate neuronal activity at electrophysiological pathway level, effects AD. This review attempts determine most effective safe device provides an overview potential current clinical indications. Several EMF have shown beneficial harmful effect cell cultures animal models but not human studies. contradictory results may be related parameters devices, frequency, penetration depth, power deposition measured absorption rate, time exposure, type cell, tissue dielectric properties. Based on this, determining optimal understanding their essential application, our suggests repeated (REMFS) appropriate treatments. Before its it necessary consider complicated interconnected genetic epigenetic REMFS-biological system interaction. will move forward urgently needed therapy

Language: Английский

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Vagus Nerve Stimulation in Ischemic Stroke

Current Neurology and Neuroscience Reports, Journal Year: 2023, Volume and Issue: 23(12), P. 947 - 962

Published: Nov. 27, 2023

Language: Английский

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Impact of transcutaneous vagus nerve stimulation on healthy cognitive and brain aging

Frontiers in Neuroscience, Journal Year: 2023, Volume and Issue: 17

Published: July 28, 2023

Evidence for clinically meaningful benefits of transcutaneous vagus nerve stimulation (VNS) has been rapidly accumulating over the past 15 years. This relatively novel non-invasive brain technique applied to a wide range neuropsychiatric disorders including schizophrenia, obsessive compulsive disorder, panic post-traumatic stress bipolar and Alzheimer’s disease. More recently, forms VNS have allowed investigations within healthy aging populations. These results offer insight into protocol considerations specific older adults how translate those effective clinical trials and, ultimately, care. In this review, we characterize possible mechanisms by which may promote (e.g., neurotransmitter effects, inflammation regulation, functional connectivity changes), special applying in an adult population changes with age), be used conjunction existing behavioral interventions cognitive therapy, training) emotional aging.

Language: Английский

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Impact of Transcutaneous Auricular Vagus Nerve Stimulation on Spatial Learning and Memory in Acrolein-Induced Alzheimer’s Disease-Like Hippocampal Neuronal Damage in Wistar Rats

Cureus, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 31, 2025

Background: Data about the utility of vagus nerve stimulation (VNS) as a potential therapy for neurodegenerative disorders are still inconclusive. We used rat model acrolein-induced hippocampal neurodegeneration to investigate effect VNS on spatial learning and memory. Methods: A total 24 Wistar rats were randomly allocated one four groups: no acrolein exposure (n = 6), control sham experimental 6). The control, sham, groups exposed 2.5 mg/kg/day by gastric gavage eight weeks. After exposure, received transcutaneous auricular greater stimulation, respectively, under 2% isoflurane anesthesia Then, all animal assessed memory in Morris water maze before being euthanized hippocampus histological examination. Results: mean time find hidden platform varied significantly between group each acrolein-exposed groups. results one-way ANOVA indicated significant difference average swimming study (F 14.64, p < 0.001). Results from post-hoc analysis that was statistically "no exposure" "control" (p 0.001), "experimental" "sham" There escape 0.060). Conclusion: Transcutaneous has or with neuronal damage, indicating need review long-standing notion loss causes navigation deficits.

Language: Английский

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Effect of Transcutaneous Vagus Nerve Stimulation with electrical stimulation on Generalized Anxiety Disorder: Study Protocol for an assessor-participant Blinded, Randomized Sham-controlled Trial

Heliyon, Journal Year: 2025, Volume and Issue: 11(4), P. e42469 - e42469

Published: Feb. 1, 2025

Generalized anxiety disorder (GAD) is the most common type of and can cause severe damage to patients increase medical social burdens. Vagus nerve stimulation (VNS) has been used for treating mental disorders, but involvement surgery, perioperative risks, potentially significant side effects have limited this treatment. Anatomical studies shown that ear only area where afferent vagus distributed on skin. Recently, safety efficacy transcutaneous auricular (t-VNS) with electrical depression epilepsy objectively evaluated. This trial trying evaluate t-VNS treatment GAD explore potential underlying neural mechanism using fMRI. An assessor-participant blinded, randomized sham-controlled will be performed. Sixty participants randomly assigned group or sham group. The last 8 weeks, once every 30 min twice a day. Four clinical assessments conducted: before treatment, at 2 4 posttreatment. primary outcome parameter categorical classification response in Hamilton Anxiety Rating Scale (HAMA) score. Functional magnetic resonance imaging (fMRI) scans applied, alterations Amplitude low-frequency fluctuations (ALFF) functional connectivity (FC) resting-state fMRI compared between two groups after Moreover, correlation changes symptoms altered ALFF FC analyzed. high-level evidence-based research expected value provide preliminary explanation its action brain imaging. In addition, use devices substantially decreased time financial costs, providing promising option complementary alternative medicine GAD, thereby advancing decisions condition. International Traditional Medicine Clinical Trial Registry, ITMCTR2022000099. Registered June 30, 2022.

Language: Английский

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Changes in brain functional connectivity associated with transcutaneous auricular vagus nerve stimulation in healthy controls

Frontiers in Human Neuroscience, Journal Year: 2025, Volume and Issue: 19

Published: March 6, 2025

A growing number of research studies have explored the potential effects vagus nerve stimulation (VNS) on brain physiology as well clinical particularly related to stress and anxiety. However, there currently are limited showing functional changes during different frequencies laterality transcutaneous auricular VNS (TaVNS). In this study, we evaluated whether TaVNS alters connectivity in healthy controls. We hypothesized that would significantly alter areas involved with emotional processing regulation including limbic areas, insula, frontal lobe regions, cerebellum. enrolled 50 Participants were placed MRI scanner compatible ear buds provided TaVNS. Subjects underwent left, right, both ears a randomized manner session. Stimulation was for 5 min then off period between. To evaluate primary outcome neurophysiological effects, all participants received blood oxygen level dependent (BOLD) magnetic resonance imaging (fMRI) states. The results demonstrated significant differed depending frequency which stimulated. general, had altered included frontoparietal Interestingly, cognitive also parts temporal lobe, salience network, default mode network. This study is an initial step toward understanding associated findings indicate changes, regulation, cognition. Future can expand data focus specific patient populations determine

Language: Английский

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Immune checkpoint inhibitors and cancer-related cognitive decline: a propensity score matched analysis in active chemotherapy patients

Frontiers in Immunology, Journal Year: 2025, Volume and Issue: 16

Published: March 7, 2025

Background We investigated whether 1-year trajectories of cancer-related cognitive decline (CRCD) would be different in patients with chemotherapy combined immune checkpoint inhibitors (chemoICI group) as compared alone (chemo group). Methods Participants scheduled or without ICI were prospectively recruited from three academic hospitals and followed up for 1 year four sessions. Subjective objective CRCD measured by Perceived Cognitive Impairment (PCI) Montreal Assessment (MoCA), respectively. Primary endpoints MoCA PCI score changes minimal clinically important difference (MCID), which was defined threshold meaningful impairment events. Propensity matching (PSM) performed group comparison using logistic regression covariates including age, cancer stage, baseline scores. Linear mixed models adjusted repeated measures. Results Out 1557 PSM yielded 460 patient pairs (1:1). Mean scores both groups reached MCID at 12-month session groups. In chemoICI, significantly lower the session, 6, 9, sessions than chemo (P&lt;0.05). One-year events risks 0.44 0.56 higher that (0.35 0.38, P&lt;0.01). Significant differences found mean event-free survival time irAE chemoICI subgroup analysis. Conclusions Our findings suggest combining ICIs may exacerbate to alone. However, reliance on screening tools self-reported measures limits definitive conclusions. Future studies incorporating comprehensive neuropsychological assessments are warranted. This study underscores importance future research better understand impact function.

Language: Английский

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Electroconvulsive therapy for neuropsychiatric symptoms in a patient with posterior cortical atrophy associated with Alzheimer's disease and a history of depression: a case report and review of the literature

Psychiatry Research Case Reports, Journal Year: 2025, Volume and Issue: unknown, P. 100256 - 100256

Published: March 1, 2025

Language: Английский

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