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Biomedicine & Pharmacotherapy =... Jun 2022Alzheimer's disease (AD) is a well-known type of age-related dementia. The present study was conducted to investigate the effect of xanthoangelol against memory deficit...
Alzheimer's disease (AD) is a well-known type of age-related dementia. The present study was conducted to investigate the effect of xanthoangelol against memory deficit and neurodegeneration associated with AD. Preliminarily, xanthoangelol produced neuroprotective effect against HO-induced HT-22 cells. Furthermore, effect of xanthoangelol against scopolamine-induced amnesia in mice was determined by intraperitoneally (i.p.) administering xanthoangelol (1, 10 and 20 mg/kg), 30 min prior to induction. Mice were administered scopolamine at a concentration of 1 mg/kg; i.p. for the induction of amnesia associated with AD. Xanthoangelol dose dependently reduced the symptoms of Alzheimer's disease as observed by the results obtained from the behavioral analysis performed using Morris water maze and Y-maze test. The immunohistochemical analysis suggested that xanthoangelol significantly improved Keap-1/Nrf-2 signaling pathway. It greatly reduced the effects of oxidative stress and showed improvement in the anti-oxidant enzyme such as GSH, GST, SOD and catalase. Additionally, xanthoangelol decreased the expression of transient receptor potential vanilloid 1 (TRPV-1), a nonselective cation channel, involved in synaptic plasticity and memory. It activated the anti-oxidants and attenuated the apoptotic (Bax/Bcl-2) pathway. Xanthoangelol also significantly attenuated the scopolamine-induced neuroinflammation by the inhibition of interleukin-1 beta (IL-1β), and tumor necrosis factor-α (TNF-α) levels. The histological analysis, showed a significant reduction in amyloid plaques by xanthoangelol. Therefore, the present study indicated that xanthoangelol has the ability to ameliorate the AD symptoms by attenuating neuroinflammation and neurodegeneration induced by scopolamine.
Topics: Alzheimer Disease; Amnesia; Animals; Antioxidants; Chalcone; GA-Binding Protein Transcription Factor; Hydrogen Peroxide; Maze Learning; Mice; Neuroprotective Agents; Oxidative Stress; Scopolamine; TRPV Cation Channels
PubMed: 35658216
DOI: 10.1016/j.biopha.2022.113073 -
The Journal of Neuroscience : the... Jun 2017Infantile amnesia, the inability of adults to recollect early episodic memories, is associated with the rapid forgetting that occurs in childhood. It has been suggested... (Review)
Review
Infantile amnesia, the inability of adults to recollect early episodic memories, is associated with the rapid forgetting that occurs in childhood. It has been suggested that infantile amnesia is due to the underdevelopment of the infant brain, which would preclude memory consolidation, or to deficits in memory retrieval. Although early memories are inaccessible to adults, early-life events, such as neglect or aversive experiences, can greatly impact adult behavior and may predispose individuals to various psychopathologies. It remains unclear how a brain that rapidly forgets, or is not yet able to form long-term memories, can exert such a long-lasting and important influence. Here, with a particular focus on the hippocampal memory system, we review the literature and discuss new evidence obtained in rats that illuminates the paradox of infantile amnesia. We propose that infantile amnesia reflects a developmental critical period during which the learning system is learning how to learn and remember.
Topics: Aging; Amnesia; Animals; Critical Period, Psychological; Evidence-Based Medicine; Hippocampus; Humans; Infant; Infant, Newborn; Memory, Long-Term; Mental Recall; Models, Neurological; Nerve Net; Rats
PubMed: 28615475
DOI: 10.1523/JNEUROSCI.0324-17.2017 -
PloS One 2023Little is known about how electrical current passes through the human body except that it follows the physical rule of least resistance. Whether organs remote from the...
INTRODUCTION
Little is known about how electrical current passes through the human body except that it follows the physical rule of least resistance. Whether organs remote from the shortest route of the current can be affected is unknown, as different types of tissue vary in resistance. This may explain why some people exposed to electrical injury report symptoms from the central nervous system (CNS). In this study, we examined the association between exposure to cross-body electrical current and immediate CNS symptoms.
MATERIAL AND METHODS
In a prospective cohort study, we followed 6960 members of the Danish Union of Electricians for 26 weeks using weekly questionnaires. We identified 2356 electrical shocks, and for each shock we asked whether the exposure was cross-body or same-side. We excluded those who reported exposure to the head as well as those who could not report the entry and exit points of the current. We examined two outcomes: becoming unconscious or having amnesia of the event. We use percentages to describe the data and logistic regression to analyze the results.
RESULTS
We found that unconsciousness and amnesia following electric shocks were rare events (0.6% and 2.2%, respectively). We found an increased risk of reporting unconsciousness and amnesia in those exposed to cross-body electrical shock exposure compared to those with same-side exposure (Odds Ratio 2.60[0.62 to 10.96] and Odds Ratio 2.18[0.87 to 5.48]).
CONCLUSION
Although the outcomes investigated are rare, we cannot rule out a possible effect on the CNS when persons are exposed to cross-body electrical current even though it does not pass through the head.
Topics: Humans; Prospective Studies; Electric Injuries; Unconsciousness; Logistic Models; Amnesia
PubMed: 37014841
DOI: 10.1371/journal.pone.0283957 -
Frontiers in Neural Circuits 2017Adaptive Resonance Theory, or ART, is a neural model that explains how normal and abnormal brains may learn to categorize and recognize objects and events in a changing... (Review)
Review
Adaptive Resonance Theory, or ART, is a neural model that explains how normal and abnormal brains may learn to categorize and recognize objects and events in a changing world, and how these learned categories may be remembered for a long time. This article uses ART to propose and unify the explanation of diverse data about normal and abnormal modulation of learning and memory by acetylcholine (ACh). In ART, determines whether learned categories will be general and abstract, or specific and concrete. ART models how vigilance may be regulated by ACh release in layer 5 neocortical cells by influencing after-hyperpolarization (AHP) currents. This ACh release is mediated by cells in the nucleus basalis (NB) of Meynert that are activated by unexpected events. The article additionally discusses data about ACh-mediated control of vigilance. ART proposes that there are often dynamic breakdowns of tonic control in mental disorders such as autism, where vigilance remains high, and medial temporal amnesia, where vigilance remains low. Tonic control also occurs during sleep-wake cycles. Properties of Up and Down states during slow wave sleep arise in ACh-modulated laminar cortical ART circuits that carry out processes in awake individuals of contrast normalization, attentional modulation, decision-making, activity-dependent habituation, and mismatch-mediated reset. These slow wave sleep circuits interact with circuits that control circadian rhythms and memory consolidation. Tonic control properties also clarify how Alzheimer's disease symptoms follow from a massive structural degeneration that includes undermining vigilance control by ACh in cortical layers 3 and 5. Sleep disruptions before and during Alzheimer's disease, and how they contribute to a vicious cycle of plaque formation in layers 3 and 5, are also clarified from this perspective.
Topics: Acetylcholine; Alzheimer Disease; Amnesia; Animals; Autistic Disorder; Brain; Humans; Learning; Memory; Models, Neurological; Sleep; Wakefulness
PubMed: 29163063
DOI: 10.3389/fncir.2017.00082 -
Drug Design, Development and Therapy 2024Remimazolam is a novel ultra-short-acting benzodiazepine sedative that has the potential to be an alternative for procedural sedation due to its rapid sedation and... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Remimazolam is a novel ultra-short-acting benzodiazepine sedative that has the potential to be an alternative for procedural sedation due to its rapid sedation and recovery, no accumulation effect, stable hemodynamics, minimal respiratory depression, anterograde amnesia effect, and specific antagonist. Here, we aimed to compare the safety and efficacy of remimazolam with dexmedetomidine for awake tracheal intubation by flexible bronchoscopy (ATI-FB).
METHODS
Ninety patients scheduled for ATI-FB were randomly divided into three groups, each consisting of 30 cases: dexmedetomidine 0.6 µg/kg + sufentanil (group DS), remimazolam 0.073 mg/kg + sufentanil (group RS), or remimazolam 0.093 mg/kg + sufentanil (group RS). The primary outcome was the success rate of sedation. Secondary outcomes were MOAA/S scores, hemodynamic and respiratory parameters, intubation conditions, intubation time, tracheal intubation amnesia, and adverse events.
RESULTS
The success rates of sedation in groups RS and DS were higher than that in group RS (93.3%, 86.7%, respectively, vs 58.6%; = 0.002), and intubation conditions were better than those in group RS ( < 0.05). Group RS had shorter intubation times than groups RS and DS ( = 0.003), and a higher incidence of tracheal intubation amnesia than group DS ( = 0.006). No patient in the three groups developed hypoxemia or hypotension, and there were no significant differences in oligopnea, PetCO, or bradycardia ( > 0.05).
CONCLUSION
In conclusion, both DS and RS had higher success rates of sedation, better intubation conditions, and minor respiratory depression, but RS, with its shorter intubation time, higher incidence of anterograde amnesia, and ability to be antagonized by specific antagonists, may be a good alternative sedation regimen for patients undergoing ATI-FB.
Topics: Humans; Amnesia; Amnesia, Anterograde; Benzodiazepines; Bronchoscopy; Dexmedetomidine; Hypnotics and Sedatives; Intubation, Intratracheal; Respiratory Insufficiency; Sufentanil; Wakefulness; Double-Blind Method
PubMed: 38562518
DOI: 10.2147/DDDT.S446222 -
Psychological Medicine Feb 2023Little is known about the neural correlates of dissociative amnesia, a transdiagnostic symptom mostly present in the dissociative disorders and core characteristic of...
BACKGROUND
Little is known about the neural correlates of dissociative amnesia, a transdiagnostic symptom mostly present in the dissociative disorders and core characteristic of dissociative identity disorder (DID). Given the vital role of the hippocampus in memory, a prime candidate for investigation is whether total and/or subfield hippocampal volume can serve as biological markers of dissociative amnesia.
METHODS
A total of 75 women, 32 with DID and 43 matched healthy controls (HC), underwent structural magnetic resonance imaging (MRI). Using Freesurfer (version 6.0), volumes were extracted for bilateral global hippocampus, cornu ammonis (CA) 1-4, the granule cell molecular layer of the dentate gyrus (GC-ML-DG), fimbria, hippocampal-amygdaloid transition area (HATA), parasubiculum, presubiculum and subiculum. Analyses of covariance showed volumetric differences between DID and HC. Partial correlations exhibited relationships between the three factors of the dissociative experience scale scores (dissociative amnesia, absorption, depersonalisation/derealisation) and traumatisation measures with hippocampal global and subfield volumes.
RESULTS
Hippocampal volumes were found to be smaller in DID as compared with HC in bilateral global hippocampus and bilateral CA1, right CA4, right GC-ML-DG, and left presubiculum. Dissociative amnesia was the only dissociative symptom that correlated uniquely and significantly with reduced bilateral hippocampal CA1 subfield volumes. Regarding traumatisation, only emotional neglect correlated negatively with bilateral global hippocampus, bilateral CA1, CA4 and GC-ML-DG, and right CA3.
CONCLUSION
We propose decreased CA1 volume as a biomarker for dissociative amnesia. We also propose that traumatisation, specifically emotional neglect, is interlinked with dissociative amnesia in having a detrimental effect on hippocampal volume.
Topics: Humans; Female; Dissociative Identity Disorder; Hippocampus; Magnetic Resonance Imaging; Amnesia; Biomarkers
PubMed: 34165068
DOI: 10.1017/S0033291721002154 -
PloS One 2021Amnesia is a core diagnostic criterion for Dissociative Identity Disorder (DID), however previous research has indicated memory transfer. As DID has been conceptualised...
Amnesia is a core diagnostic criterion for Dissociative Identity Disorder (DID), however previous research has indicated memory transfer. As DID has been conceptualised as being a disorder of distinct identities, in this experiment, behavioral tasks were used to assess the nature of amnesia for episodic 1) self-referential and 2) autobiographical memories across identities. Nineteen DID participants, 16 DID simulators, 21 partial information, and 20 full information comparison participants from the general population were recruited. In the first study, participants were presented with two vignettes (DID and simulator participants received one in each of two identities) and asked to imagine themselves in the situations outlined. The second study used a similar methodology but with tasks assessing autobiographical experience. Subjectively, all DID participants reported amnesia for events that occurred in the other identity. On free recall and recognition tasks they presented a memory profile of amnesia similar to simulators instructed to feign amnesia and partial information comparisons. Yet, on tests of recognition, DID participants recognized significantly more of the event that occurred in another identity than simulator and partial information comparisons. As such, results indicate that the DID performance profile was not accounted for by true or feigned amnesia, lending support to the idea that reported amnesia may be more of a perceived than actual memory impairment.
Topics: Adult; Amnesia; Dissociative Identity Disorder; Female; Humans; Male; Memory, Episodic; Mental Recall; Recognition, Psychology
PubMed: 33577556
DOI: 10.1371/journal.pone.0245849 -
Intensive & Critical Care Nursing Aug 2017This review aims to use thematic analysis to explore and synthesise evidence of the actual or potential reported effects of diaries on the psychological rehabilitation... (Review)
Review
AIM
This review aims to use thematic analysis to explore and synthesise evidence of the actual or potential reported effects of diaries on the psychological rehabilitation and recovery of discharged critical care patients.
BACKGROUND
Evidence suggests that whilst admission to critical care may save patient lives, the psychological aftermath can damage a patient's recovery and these needs must be met. Patient diaries are one potential intervention to aid patients understand their critical illness and fill memory gaps caused by sedation, thus reducing psychological distress post-discharge. Prospective patient diaries are increasing in popularity amongst critical care units in the United Kingdom, however there is little evidence base to support their use or understand their effects.
METHOD
A literature review using systematic methods was undertaken of studies relating to the effects of diaries on discharged patients. Thematic analysis enabled the generation and synthesis of themes.
RESULTS
Three themes arose from the generated codes: 1) Reclaiming ownership of lost time. 2) Emphasising personhood. 3) Fear and frustration. The diary intervention was shown to have a largely positive impact on survivors' psychological rehabilitation. However, caution should be exercised as recipients could find the contents painful and emotional. Diaries should be embedded within a robust critical care follow-up plan.
CONCLUSION
This review suggests that diaries have the potential to form one aspect of rehabilitation and make a positive impact on patients' recovery. More research is indicated to fully evaluate the effects of diaries on their recipients.
Topics: Adult; Amnesia; Critical Illness; Family; Female; Humans; Intensive Care Units; Male; Medical Records; Survivors; United Kingdom
PubMed: 28363594
DOI: 10.1016/j.iccn.2017.03.002 -
Neuropsychologia Dec 2023To understand the neural basis of episodic memory it is necessary to appreciate the significance of the fornix. This pathway creates a direct link between those temporal...
To understand the neural basis of episodic memory it is necessary to appreciate the significance of the fornix. This pathway creates a direct link between those temporal lobe and medial diencephalic sites responsible for anterograde amnesia. A collaboration with Andrew Mayes made it possible to recruit and scan 38 patients with colloid cysts in the third ventricle, a condition associated with variable fornix damage. Complete fornix loss was seen in three patients, who suffered chronic long-term memory problems. Volumetric analyses involving all 38 patients then revealed a highly consistent relationship between mammillary body volume and the recall of episodic memory. That relationship was not seen for working memory or tests of recognition memory. Three different methods all supported a dissociation between recollective-based recognition (impaired) and familiarity-based recognition (spared). This dissociation helped to show how the mammillary body-anterior thalamic nuclei axis, as well as the hippocampus, is vital for episodic memory yet is not required for familiarity-based recognition. These findings set the scene for a reformulation of temporal lobe and diencephalic amnesia. In this revised model, these two regions converge on overlapping cortical areas, including retrosplenial cortex. The united actions of the hippocampal formation and the anterior thalamic nuclei on these cortical areas enable episodic memory encoding and consolidation, impacting on subsequent recall.
Topics: Humans; Memory, Episodic; Diencephalon; Hippocampus; Amnesia; Mental Recall; Mammillary Bodies
PubMed: 37939875
DOI: 10.1016/j.neuropsychologia.2023.108728 -
Neuroscience and Biobehavioral Reviews Jul 2015In this review, the clinical, neuropsychological, and neuroimaging findings in the alcoholic Korsakoff syndrome and in thalamic amnesia, resulting from focal infarction,... (Review)
Review
In this review, the clinical, neuropsychological, and neuroimaging findings in the alcoholic Korsakoff syndrome and in thalamic amnesia, resulting from focal infarction, are compared. In both disorders, there is controversy over what is the critical site for anterograde amnesia to occur-damage to the anterior thalamus/mammillo-thalamic tract has most commonly been cited, but damage to the medio-dorsal nuclei has also been advocated. Both syndromes show 'core' features of an anterograde amnesic syndrome; but retrograde amnesia is generally much more extensive (going back many years or decades) in the Korsakoff syndrome. Likewise, spontaneous confabulation occurs more commonly in the Korsakoff syndrome, although seen in only a minority of chronic cases. These differences are attributed to the greater prevalence of frontal atrophy and frontal damage in Korsakoff cases.
Topics: Alcohol Amnestic Disorder; Amnesia, Anterograde; Amnesia, Retrograde; Brain Infarction; Confusion; Humans; Thalamus
PubMed: 25218758
DOI: 10.1016/j.neubiorev.2014.08.014