Search results for "Memory impairment"
showing 10 items of 25 documents
Drosophila Full-Length Amyloid Precursor Protein is Required for Visual Working Memory and Prevents Age-Related Memory Impairment
2018
Summary The β-amyloid precursor protein (APP) plays a central role in the etiology of Alzheimer's disease (AD). However, its normal physiological functions are still unclear. APP is cleaved by various secretases whereby sequential processing by the β- and γ-secretases produces the β-amyloid peptide that is accumulating in plaques that typify AD. In addition, this produces secreted N-terminal sAPPβ fragments and the APP intracellular domain (AICD). Alternative cleavage by α-secretase results in slightly longer secreted sAPPα fragments and the identical AICD. Whereas the AICD has been connected with transcriptional regulation, sAPPα fragments have been suggested to have a neurotrophic and neu…
Differential role of interleukin-1β in neuroinflammation-induced impairment of spatial and nonspatial memory in hyperammonemic rats.
2019
Activated microglia and increased brain IL-1β play a main role in cognitive impairment in much pathology. We studied the role of IL-1β in neuroinflammation-induced impairment of the following different types of learning and memory: novel object recognition (NOR), novel object location (NOL), spatial learning, reference memory (RM), and working memory (WM). All these processes are impaired in hyperammonemic rats. We assessed which of these types of learning and memory are restored by blocking the IL-1 receptor in vivo in hyperammonemic rats and the possible mechanisms involved. Blocking the IL-1 receptor reversed microglial activation in the hippocampus, perirhinal cortex, and prefrontal cor…
Indomethacin counteracts the effects of chronic social defeat stress on emotional but not recognition memory in mice
2017
We have previously observed the impairing effects of chronic social defeat stress (CSDS) on emotional memory in mice. Given the relation between stress and inflammatory processes, we sought to study the effectiveness of the anti-inflammatory indomethacin in reversing the detrimental effects of CSDS on emotional memory in mice. The effects of CSDS and indomethacin on recognition memory were also evaluated. Male CD1 mice were randomly divided into four groups: non-stressed + saline (NS+SAL); non-stressed + indomethacin (NS+IND); stressed + saline (S+SAL); and stressed + indomethacin (S+IND). Stressed animals were exposed to a daily 10 min agonistic confrontation (CSDS) for 20 days. All subjec…
Confabulation: damage to a specific inferior medial prefrontal system
2008
Confabulation, the pathological production of false memories, occurs following a variety of aetiologies involving the frontal lobes, and is frequently held to be underpinned by combined memory and executive deficits. However, the critical frontal regions and specific cognitive deficits involved are unclear. Studies in amnesic patients have associated confabulation with damage to the orbital and ventromedial prefrontal cortices. However, neuroimaging studies have associated memory-control processes which are assumed to underlie confabulation with the right lateral prefrontal cortex. We used a confabulation battery to investigate the occurrence and localisation of confabulation in an unselect…
A Comparison of implicit memory tests in schizophrenic patients and normal controls
2007
The objective of the current study was to compare the performance of schizophrenic patients and normal controls on implicit memory tests. Two neuropsychological tasks were administered to 29 patients and normal participant samples. The implicit tests were: Word fragment completion and Word production from semantic categories. The priming score was the variable of interest. Priming effects are obtained in normal subjects and schizophrenia patients, regardless of the implicit test used. However, a dissociation in priming between normal and patient groups was observed, depending on the test used. For word fragment test, priming was identical between... (Ver más) the two groups. However, for wo…
A combined electrophysiological and morphological examination of episodic memory decline in amnestic mild cognitive impairment.
2013
Early stages of Alzheimer’s disease (AD) are characterized by neuropathological changes within the medial temporal lobe cortex (MTLC), which lead to characteristic impairments in episodic memory, i.e., amnestic mild cognitive impairment (aMCI). Here, we tested the neural correlates of this memory impairment using event-related potentials (ERPs) and voxel-based morphometry. Twenty-four participants were instructed to encode lists of words and were tested in a yes/no recognition memory task. The dual-process model of recognition memory dissociates between acontextual familiarity and recollection of contextual details. The early frontal ERP old/new-effect, which is thought to represent a neura…
Anosognosia and Metacognition in Alzheimer’s Disease
2015
While metacognition and anosognosia have long been studied as distinct concepts, more recently we have endeavored to construct a theoretical framework for exploring how metacognition can contribute to our understanding of anosognosia and vice versa. Following this approach, with a particular focus on Alzheimer’s disease (AD), this chapter first gives an overview of the key experimental findings and issues on metacognition in AD patients: in particular, overconfidence and absolute awareness; the sensitivity approach; the fractionation of metacognition in AD; the neural substrates of metacognition in the Alzheimer brain; and metacognitive control in these patients. Second, the chapter discuss…
Analysis of Functional and Cognitive Impairment in Institutionalized Individuals with Movement Disorders
2018
Background: Many neurological disorders lead to institutionalization and can be accompanied in their advanced stages by functional impairment, and progressive loss of mobility, and cognitive alterations. Objective: We analyzed the relationship between functional impairment and cognitive performance and its related subdomains in individuals with Parkinson’s disease, Alzheimer’s disease accompanied by motor dysfunction, and with other neurological disorders characterized by both motor and cognitive problems. Methods: All participants lived in nursing homes (Valencia, Spain) and underwent cognitive evaluation with the Mini-Mental State Examination; functional assessment of independence in act…
Age differences in the role of the cannabinoid type 1 receptor on glutamatergic neurons in habituation and spatial memory acquisition
2015
Abstract Aims Aging is typically linked with a decline in memory performance and alterations in neural integrity. In pathological aging such as Alzheimer's disease, these effects are aggravated. Studies using cannabinoid CB1 receptor-deficient mice have shown a role of the endocannabinoid system in memory processing and neuroprotection. As the CB1 receptor is expressed in various neuronal populations, in this study, we aimed at investigating the consequences of CB1 receptor gene inactivation in cortical glutamatergic neurons in mice (Glu-CB1-KO) in regard to age-related alterations in spatial memory performance. Main methods Juvenile (5.5–7.5 weeks), adult (5.5–7 months), and old (11.5–14 m…
Short-Term Long Chain Omega3 Diet Protects from Neuroinflammatory Processes and Memory Impairment in Aged Mice
2011
Regular consumption of food enriched in omega3 polyunsaturated fatty acids (oméga3 PUFAs) has been shown to reduce risk of cognitive decline in elderly, and possibly development of Alzheimer's disease. Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are the most likely active components of oméga3-rich PUFAs diets in the brain. We therefore hypothesized that exposing mice to a DHA and EPA enriched diet may reduce neuroinflammation and protect against memory impairment in aged mice. For this purpose, mice were exposed to a control diet throughout life and were further submitted to a diet enriched in EPA and DHA during 2 additional months. Cytokine expression together with a thoroug…