-
Physiology & Behavior Feb 2021Diabetes is a prevalent metabolic disorder that has long been associated with changes in different regions of the brain, including the hippocampus. Changes in...
Diabetes is a prevalent metabolic disorder that has long been associated with changes in different regions of the brain, including the hippocampus. Changes in hippocampal synaptic plasticity and subsequent impairment in cognitive functions such as learning and memory, are well documented in animal models of type 1 and type 2 diabetes. It is known that RAGE contributes to peripheral micro- and macro-vascular complications of diabetes. However, it is still unknown if RAGE plays a similar role in the development of CNS complications of diabetes. Therefore, we hypothesize that RAGE contributes to cognitive dysfunction, such as learning and memory impairments, in a mouse model of STZ-induced hyperglycemia. Control and STZ-induced hyperglycemic mice from WT and RAGE-KO groups were used for the behavioral experiments. While STZ-induced hyperglycemia decreased locomotor activity in the open field (OF) test, it did not affect the recognition memory in the novel object recognition (NOR) test in either genotype. Spatial memory, however, was impaired in STZ-induced hyperglycemic mice in WT but not in RAGE-KO group in both the Barnes maze (BM) and the Morris water maze (MWM) tests. Consistently, the RAGE antagonist FPS-ZM1 protected WT STZ-induced hyperglycemic mice from spatial memory impairment in the BM test. Our findings indicate that the parameters associated with locomotor activity and recognition memory were independent of RAGE in STZ-induced hyperglycemic mice. In contrast, the parameters associated with hippocampal-dependent spatial memory were dependent on RAGE expression.
Topics: Animals; Diabetes Mellitus, Type 2; Hippocampus; Hyperglycemia; Maze Learning; Memory Disorders; Mice; Spatial Memory
PubMed: 33316294
DOI: 10.1016/j.physbeh.2020.113287 -
Neuropsychology Sep 2020Attention-deficit/hyperactivity disorder (ADHD) has been associated with large magnitude impairments in working memory, whereas short-term memory deficits, when...
Attention-deficit/hyperactivity disorder (ADHD) has been associated with large magnitude impairments in working memory, whereas short-term memory deficits, when detected, tend to be less pronounced. However, confidence in these findings is limited due to task impurity combined with methodological and statistical limitations of the current evidence base. A well-characterized, clinically evaluated sample of 172 children ages 8-13 years ( = 10.30, = 1.42; 72 girls; 64% White/non-Hispanic) were administered multiple, counterbalanced working memory tests. Bifactor-(s-1) modeling was used to characterize the presence and magnitude of central executive working memory, phonological short-term memory, and visuospatial short-term memory deficits in pediatric ADHD. ADHD status was associated with very large magnitude impairments in central executive working memory that are present in most pediatric cases ( = 1.63-2.03; 75%-81% impaired), and these deficits covaried with ADHD inattentive and hyperactive/impulsive symptom severity based on both parent and teacher report. There was also evidence for a unique, albeit significantly smaller, impairment in visuospatial short-term memory ( = 0.60; 38% impaired); however, visuospatial short-term memory abilities did not covary with ADHD symptom severity. There was no evidence linking ADHD with phonological short-term memory deficits across either the dimensional or categorical analyses. These findings provide strong evidence that ADHD is associated with marked central executive working memory deficits that covary with their behavioral symptom presentation across settings. In contrast, visuospatial short-term memory deficits, when present, are likely epiphenomenal, and the most parsimonious conclusion appears to be that phonological short-term memory is intact in pediatric ADHD. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
Topics: Adolescent; Attention Deficit Disorder with Hyperactivity; Child; Executive Function; Female; Humans; Male; Memory Disorders; Memory, Short-Term; Models, Psychological; Neuropsychological Tests; Parents; School Teachers; Spatial Memory
PubMed: 32437194
DOI: 10.1037/neu0000641 -
Current Opinion in Pharmacology Feb 2015Positive allosteric modulators of ionotropic glutamate receptors have emerged as a target for treating cognitive impairment and neurodegeneration, but also mental... (Review)
Review
Positive allosteric modulators of ionotropic glutamate receptors have emerged as a target for treating cognitive impairment and neurodegeneration, but also mental illnesses such as major depressive disorder. The possibility of creating a new class of pharmaceutical agent to treat refractive mental health issues has compelled researchers to redouble their efforts to develop a safe, effective treatment for memory and cognition impairments. Coupled with the more robust research methodologies that have emerged, including more sophisticated high-throughput-screens, higher resolution structural biology techniques, and more focused assessment on pharmacokinetics, the development of positive modulators of AMPA receptors holds great promise. We describe recent approaches that improve our understanding of the basic physiology underlying memory and cognition, and their application toward promoting human health.
Topics: Allosteric Regulation; Animals; Cognition; Cognition Disorders; Depressive Disorder, Major; Drug Design; High-Throughput Screening Assays; Humans; Memory Disorders; Mental Disorders; Receptors, AMPA
PubMed: 25462292
DOI: 10.1016/j.coph.2014.11.002 -
Current Neurology and Neuroscience... Aug 2017A paradigm shift in contemporary epileptology has been the reframing of both epilepsy and its comorbid memory disorders as the product of diseased brain networks. The... (Review)
Review
PURPOSE OF REVIEW
A paradigm shift in contemporary epileptology has been the reframing of both epilepsy and its comorbid memory disorders as the product of diseased brain networks. The current review discusses some of the clinical and theoretical implications that stem from this shift.
RECENT FINDINGS
Some implications of a network conceptualisation of epilepsy include a need for more widespread cognitive phenotyping in epilepsy; recognition that memory disorders in epilepsy can be multi-determined, including by non-structural factors; deeper consideration given to the neurodevelopmental context in which memory problems emerge; the utility of new methods to characterise memory impairments in epilepsy; and a call for greater recognition of the close interrelationships between memory comorbidities and psychiatric symptoms in epilepsy. Memory disorder significantly worsens the quality of life of people with epilepsy, underscoring the importance to patient wellbeing of giving due consideration to the up-to-date neuropsychological practises outlined in this review.
Topics: Brain; Comorbidity; Epilepsy; Humans; Memory Disorders; Mental Disorders; Neural Pathways
PubMed: 28631193
DOI: 10.1007/s11910-017-0765-7 -
Journal of Neuropsychology Sep 2014Conversion disorder (CD) is a condition where neurological symptoms, such as weakness or sensory disturbance, are unexplained by neurological disease and are presumed to...
Conversion disorder (CD) is a condition where neurological symptoms, such as weakness or sensory disturbance, are unexplained by neurological disease and are presumed to be of psychological origin. Contemporary theories of the disorder generally propose dysfunctional frontal control of the motor or sensory systems. Classical (Freudian) psychodynamic theory holds that the memory of stressful life events is repressed. Little is known about the frontal (executive) function of these patients, or indeed their general neuropsychological profile, and psychodynamic theories have been largely untested. This study aimed to investigate neuropsychological functioning in patients with CD, focusing on executive and memory function. A directed forgetting task (DFT) using words with variable emotional valence was also used to investigate memory suppression. 21 patients and 36 healthy controls completed a battery of neuropsychological tests and patients had deficits in executive function and auditory-verbal (but not autobiographical) memory. The executive deficits were largely driven by differences in IQ, anxiety and mood between the groups. A subgroup of 11 patients and 28 controls completed the DFT and whilst patients recalled fewer words overall than controls, there were no significant effects of directed forgetting or valence. This study provides some limited support for deficits in executive, and to a lesser degree, memory function in patients with CD, but did not find evidence of altered memory suppression to support the psychodynamic theory of repression.
Topics: Adult; Analysis of Variance; Cognition Disorders; Conversion Disorder; Female; Humans; Male; Memory Disorders; Mental Recall; Middle Aged; Neuropsychological Tests; Statistics as Topic
PubMed: 23582098
DOI: 10.1111/jnp.12017 -
NeuroImage. Clinical 2016Prevailing neuropsychological models of attention-deficit/hyperactivity disorder (ADHD) propose that ADHD arises from deficits in executive functions such as working...
Prevailing neuropsychological models of attention-deficit/hyperactivity disorder (ADHD) propose that ADHD arises from deficits in executive functions such as working memory, but accumulating clinical evidence suggests a dissociation between ADHD and executive dysfunctions. This study examined whether ADHD and working memory capacity are behaviorally and neurobiologically separable using functional magnetic resonance imaging (fMRI). Participants diagnosed with ADHD in childhood who subsequently remitted or persisted in their diagnosis as adults were characterized at follow-up in adulthood as either impaired or unimpaired in spatial working memory relative to controls who never had ADHD. ADHD participants with impaired spatial working memory performed worse than controls and ADHD participants with unimpaired working memory during an n-back working memory task while being scanned. Both controls and ADHD participants with unimpaired working memory exhibited significant linearly increasing activation in the inferior frontal junction, precuneus, lingual gyrus, and cerebellum as a function of working-memory load, and these activations did not differ significantly between these groups. ADHD participants with impaired working memory exhibited significant hypoactivation in the same regions, which was significantly different than both control participants and ADHD participants with unimpaired working memory. These findings support both a behavioral and neurobiological dissociation between ADHD and working memory capacity.
Topics: Adolescent; Attention Deficit Disorder with Hyperactivity; Brain; Brain Mapping; Child; Executive Function; Female; Humans; Magnetic Resonance Imaging; Male; Memory Disorders; Memory, Short-Term
PubMed: 26900567
DOI: 10.1016/j.nicl.2015.12.003 -
Journal of Clinical and Experimental... Apr 2022The present study aims to examine whether declarative memory dysfunction relates to impaired core memory mechanisms or attentional and executive dysfunction in... (Observational Study)
Observational Study
OBJECTIVE
The present study aims to examine whether declarative memory dysfunction relates to impaired core memory mechanisms or attentional and executive dysfunction in idiopathic REM Sleep Behavior Disorder (iRBD).
METHOD
In this observational, cross-sectional study, were enrolled 82 individuals with the diagnosis of iRBD according to the International Classification of Sleep Disorders and 49-matched healthy controls fulfilling inclusion criteria. All participants underwent two memory tasks, namely the Rey Auditory Verbal Learning Test (RAVLT) and Memory Binding Test (MBT), which include conditions of varying degrees of dependence on executive functioning, as well as different indicators of core memory processes (e.g., learning, retention, relational binding).
RESULTS
We used Bayesian multivariate generalized linear model analysis to evaluate the effect of iRBD on memory performance controlled for effects of age and sex. Individuals with iRBD displayed worse memory performance in the delayed free recall task ( = -0.37, 95% PPI [-0.69, -0.05]), but not on delayed recognition of the same material. Their performance in cued recall tasks both in immediate and delayed conditions was in comparison to controls relatively spared. Moreover, the deficit in delayed free recall was mediated by attention/processing speed.
CONCLUSIONS
In iRBD, we replicated findings of reduced free recall based on inefficient retrieval (retrieval deficit), which was small in terms of effect size. Importantly, the memory profile across measures does not support the presence of core memory dysfunction, such as poor learning, retention or associative binding.
Topics: Bayes Theorem; Cognitive Dysfunction; Cross-Sectional Studies; Humans; Memory Disorders; Neuropsychological Tests; REM Sleep Behavior Disorder
PubMed: 35986521
DOI: 10.1080/13803395.2022.2107182 -
Journal of Neurodevelopmental Disorders Nov 2023ATRX is an ATP-dependent chromatin remodeling protein with essential roles in safeguarding genome integrity and modulating gene expression. Deficiencies in this protein...
BACKGROUND
ATRX is an ATP-dependent chromatin remodeling protein with essential roles in safeguarding genome integrity and modulating gene expression. Deficiencies in this protein cause ATR-X syndrome, a condition characterized by intellectual disability and an array of developmental abnormalities, including features of autism. Previous studies demonstrated that deleting ATRX in mouse forebrain excitatory neurons postnatally resulted in male-specific memory deficits, but no apparent autistic-like behaviours.
METHODS
We generated mice with an earlier embryonic deletion of ATRX in forebrain excitatory neurons and characterized their behaviour using a series of memory and autistic-related paradigms.
RESULTS
We found that mutant mice displayed a broader spectrum of impairments, including fear memory, decreased anxiety-like behaviour, hyperactivity, as well as self-injurious and repetitive grooming. Sex-specific alterations were also observed, including male-specific aggression, sensory gating impairments, and decreased social memory.
CONCLUSIONS
Collectively, the findings indicate that early developmental abnormalities arising from ATRX deficiency in forebrain excitatory neurons contribute to the presentation of fear memory deficits as well as autistic-like behaviours.
Topics: Female; Mice; Male; Animals; Autistic Disorder; Neurons; Memory Disorders; Cognition
PubMed: 37957569
DOI: 10.1186/s11689-023-09508-7 -
Schizophrenia Bulletin Jan 2016Meta-analyses and reviews on cognitive disorders in schizophrenia have shown that the most robust and common cognitive deficits are found in episodic memory and... (Meta-Analysis)
Meta-Analysis Review
Meta-analyses and reviews on cognitive disorders in schizophrenia have shown that the most robust and common cognitive deficits are found in episodic memory and executive functions. More complex memory domains, such as autobiographical memory (AM), are also impaired in schizophrenia, but such impairments are reported less often despite their negative impact on patients' outcome. In contrast to episodic memory, assessed in laboratory tasks, memories of past personal events are much more complex and directly relate to the self. The meta-analysis included 20 studies, 571 patients with schizophrenia spectrum disorder, and 503 comparison subjects. It found moderate-to-large effect sizes with regard to the 3 parameters commonly used to assess AM: memory specificity (g = -0.97), richness of detail (g = -1.40), and conscious recollection (g = -0.62). These effect sizes were in the same range as those found in other memory domains in schizophrenia; for this reason, we propose that defective memories of personal past events should be regarded as a major cognitive impairment in this illness.
Topics: Executive Function; Humans; Memory Disorders; Memory, Episodic; Mental Recall; Psychiatric Rehabilitation; Schizophrenia; Schizophrenic Psychology; Self Concept
PubMed: 26209548
DOI: 10.1093/schbul/sbv099 -
Oxidative Medicine and Cellular... 2020This study was conducted to assess the protective effect of extract of match (EM) on high-fat diet- (HFD-) induced cognitive deficits in male C57BL/6 mice. It was found...
This study was conducted to assess the protective effect of extract of match (EM) on high-fat diet- (HFD-) induced cognitive deficits in male C57BL/6 mice. It was found that EM improved glucose tolerance status by measuring OGTT and IPGTT with HFD-induced mice. EM protected behavioral and memory dysfunction in Y-maze, passive avoidance, and Morris water maze tests. Consumption of EM reduced fat mass, dyslipidemia, and inflammation in adipose tissue. Also, EM ameliorated hepatic and cerebral antioxidant systems. EM improved the cerebral cholinergic system by regulating ACh contents and expression of AChE and ChAT. Also, EM restored mitochondrial function in liver and brain tissue. EM attenuated hepatic inflammatory effect, lipid synthesis, and cholesterol metabolism by regulating the protein expression of TNF-, TNFR1, -IRS-1, -JNK, IL-1, iNOS, COX-2, HMGCR, PPAR, and FAS. Finally, EM regulated cognitive function and neuroinflammation in the whole brain, hippocampus, and cerebral cortex by regulating the protein expression of -JNK, -Akt, -tau, A, BDNF, IDE, COX-2, and IL-1. These findings suggest that EM might be a potential source of functional food to improve metabolic disorder-associated cognitive dysfunction.
Topics: Adipose Tissue; Animals; Cognitive Dysfunction; Diet, High-Fat; Dyslipidemias; Gene Expression Regulation; Inflammation; Male; Memory Disorders; Mice; Panniculitis; Tea
PubMed: 33312340
DOI: 10.1155/2020/8882763