Purpose: The present study aimed at evaluating possible synergistic effects between two risk factors for cognitive decline and neurodegenerative disorders, i.e. iron overload and exposure to a hypercaloric/hyperlipidic diet, on cognition, insulin resistance, and hippocampal GLUT1, GLUT3, Insr mRNA expression, and AKT phosporylation.
View Article and Find Full Text PDFSocial deprivation can be stressful for group-living mammals. On the other hand, an amazing response of these animals to stress is seeking social contact to give and receive joint protection in threatening situations. We explored the effects of social isolation and social support on epigenetic and behavioral responses to chronic stress.
View Article and Find Full Text PDFFront Behav Neurosci
September 2021
Social networks can modulate physiological responses, protects against the detrimental consequences of prolonged stress, and enhance health outcomes. Family ties represent an essential source of social networks among older adults. However, the impact of family support on cognitive performance and the biological factors influencing that relationship is still unclear.
View Article and Find Full Text PDFClinical and preclinical evidence has indicated that estrogen depletion leads to memory impairments and increases the susceptibility to neural damage. Here, we have sought to investigate the effects of Cannabidiol (CBD) a non-psychotomimetic compound from Cannabis sativa, on memory deficits induced by estrogen depletion in rats, and its underlying mechanisms. Adult rats were subjected to bilateral ovariectomy, an established estrogen depletion model in rodents, or sham surgery and allowed to recover for three weeks.
View Article and Find Full Text PDFEstrogens, particularly 17β-estradiol (estradiol, E), regulate memory formation. E2 acts through its intracellular receptors, estrogen receptors (ER) ERα and ERβ, as well as a recently identified G protein-coupled estrogen receptor (GPER). Although the effects of E2 on memory have been investigated, studies examining the effects of GPER stimulation are scarce.
View Article and Find Full Text PDFIntroduction: Depression is characterized by behavioral, cognitive and physiological changes, imposing a major burden on the overall wellbeing of the patient. Some evidence indicates that social stress, changes in growth factors (e.g.
View Article and Find Full Text PDFOver the years, iron accumulation in specific brain regions has been observed in normal aging and related to the pathogenesis of neurodegenerative disorders. Many neurodegenerative diseases may involve cognitive dysfunction, and we have previously shown that neonatal iron overload induces permanent cognitive deficits in adult rats and exacerbates age-associated memory decline. Autophagy is a catabolic pathway involved in the removal of toxic protein aggregates, which are a hallmark of neurodegenerative events.
View Article and Find Full Text PDFThe role of mBDNF on the beneficial effects of cognitive stimulation on the brain remains controversial, as well as the potential of peripheral mBDNF as a biomarker of environmental effects on its central status. We investigated the effect of different environmental conditions on recognition memory, proBDNF, mBDNF and synaptophysin levels in the hippocampus, and on mBDNF levels in blood. Male Wistar rats (6 and 17 months-old) were assigned to cognitively enriched (EE), standard (SE) and impoverished (IE) environmental conditions for twelve weeks.
View Article and Find Full Text PDFBehav Brain Res
July 2019
Epigenetic modulation of brain-derived neurotrophic factor (BDNF) provides one possible explanation for the dysfunctions induced by stress, such as psychiatric disorders and cognitive decline. Interestingly, social support can be protective against some of these effects, but the mechanisms of social buffering are poorly understood. Conversely, early isolation exacerbates the responses to stressors, although its effects in adulthood remain unclear.
View Article and Find Full Text PDFContextual memory is susceptible to the effects of aging and its impairment compromises episodic memories and quality of life in older adults. Compare the effects of cognitive support on incidental contextual memory free recall and recognition with a naturalistic experimental paradigm and explore the association of encoding strategies and physical activity on memory improvement. Subjects (≥60 years, n = 52) were assigned to one of two encoding conditions for the contextual memory task: with or without an incidental associative instruction to encourage association of an item to its spatial context.
View Article and Find Full Text PDFFamilial caregivers of Alzheimer's disease (AD) patients experience an emotional and physical burden which characterizes a chronic stress condition. The resulting hypothalamic-pituitary-adrenal axis dysfunction favors an imbalance of neurotoxic/neuroprotective factors and causes cognitive impairments, increasing the caregivers' risk for cognitive decline and compromising their ability to provide adequate care of the patient. Therefore, the present study aimed to investigate the reversibility of the cognitive impairments of familial caregivers of AD patients during their caregiving-related chronic stress condition.
View Article and Find Full Text PDFBrain-derived neurotrophic factor (BDNF) is one of the most studied neurotrophins in the healthy and diseased brain. As a result, there is a large body of evidence that associates BDNF with neuronal maintenance, neuronal survival, plasticity, and neurotransmitter regulation. Patients with psychiatric and neurodegenerative disorders often have reduced BDNF concentrations in their blood and brain.
View Article and Find Full Text PDFPhysical activity has been proposed as a promising intervention to improve cognition and decrease the risk of dementia in older adults. Brain-derived neurotrophic factor (BDNF) appears to mediate, at least partially, these effects of exercise. However, intervention studies of the effects of multimodal exercises on cognition and BDNF levels are scarce and composed by small samples.
View Article and Find Full Text PDFObjectives: Older familial caregivers of Alzheimer's disease patients are subjected to stress-related cognitive and psychophysiological dysfunctions that may affect their quality of life and ability to provide care. Younger caregivers have never been properly evaluated. We hypothesized that they would show qualitatively similar cognitive and psychophysiological alterations to those of older caregivers.
View Article and Find Full Text PDFBackground: Neuroimaging studies suggest that acute sleep deprivation can lead to adaptations, such as compensatory recruitment of cerebral structures, to maintain cognitive performance despite sleep loss. However, the understanding of the neurochemical alterations related to these adaptations remains incomplete.
Objective: Investigate BDNF levels, cognitive performance and their relations in healthy subjects after acute sleep deprivation.
Contextual memory is important for the encoding and retrieval of episodic memory, which is often impaired in euthymic patients with bipolar disorder (BD). The objective was to investigate the effect of low and high cognitive support on encoding in an incidental contextual memory task in euthymic patients with BD. Twenty-three patients with a BD type I diagnosis (aged 23-63 years, 17 women and 6 men) and 29 healthy controls completed a recognition memory task for context (location of a recognised object).
View Article and Find Full Text PDFThe primary purpose of this study was to investigate the effect of dual-tasking on cognitive performance and gait parameters in patients with idiopathic Parkinson's disease (PD) without dementia. The impact of cognitive task complexity on cognition and walking was also examined. Eighteen patients with PD (ages 53-88, 10 women; Hoehn and Yahr stage I-II) and 18 older adults (ages 61-84; 10 women) completed two neuropsychological measures of executive function/attention (the Stroop Test and Wisconsin Card Sorting Test).
View Article and Find Full Text PDFObjectives: To investigate the effect of cognitive support (an associative orienting instruction at encoding) on contextual memory in depressed patients.
Methods: Seventeen patients (age 20-40 years, 14 women) diagnosed with major depressive disorder (MDD) and 22 healthy controls matched for age, gender and education completed a recognition memory task for item (object) and context (location), with or without an incidental binding cue at encoding. In addition, participants completed the vocabulary subtest of the Wechsler Adult Intelligence Scale (WAIS III) and the Wisconsin Card Sorting Test (WCST).
This study examined the cortisol secretion pattern and declarative memory performance of dementia caregivers. An illustrated story paradigm memory task was used to evaluate the effects of emotional arousal on memory and assess the caregivers' cognitive compensation capacity. Younger (n=19) and elderly (n=24) noncaregivers and elderly caregivers (n=14) took part in 2 experiments to elucidate the effects of aging (experiment 1) and chronic stress (experiment 2) on memory performance and cortisol levels.
View Article and Find Full Text PDFBackground: Alterations in cortisol secretion pattern seem to be involved in the associations between aging, depression, and cognitive decline.
Objective: The aim of this study was to mainly assess cortisol circadian profile in older adults with subjective depressive symptoms.
Methods: Salivary cortisol samples from healthy young (n = 22) and old adults (n = 22), and from older adults who self-reported depressive symptoms in Geriatric Depression Scale (n = 22) were collected at 7 AM, 4 PM, and 10 PM and were analyzed by radioimmunoassay.
Background: This study investigated the performance of patients with idiopathic Parkinson's disease (PD) without dementia for incidental recognition memory and the effect of encoding strategies on contextual memory.
Methods: The authors studied 21 patients with PD (ages 60-85, 12 women; Hoehn and Yahr I-III, Activities of Daily Living 70%-100%) and 22 healthy controls (ages 60-84, 18 women). Participants completed the vocabulary subtest of the Wechsler Adult Intelligence Scale and the Wisconsin Card Sorting Test (WCST).
Objectives: This study examines the role of depressive symptoms associated with age on contextual memory and how this association could impair the use of strategic instructions during encoding.
Method: Young and older controls and older adults with depressive symptoms performed memory recognition tests for item and context.
Results: Memory results indicated that mild depressive symptoms did not aggravate the age-related contextual memory pattern, but interfered with the magnitude of the memory enhancement provided by specific encoding instructions when compared with young adults.
We have previously demonstrated that rats given iron neonatally presented memory deficits. The aim of the present study was to evaluate the effect of desferoxamine, a metal chelating agent, on memory deficits in an iron overload model in rats. Male rats received vehicle or iron orally at postnatal days 12-14 and desferoxamine (30 or 300 mg/kg) in the adulthood.
View Article and Find Full Text PDFIt is now generally accepted that iron accumulates in the brain during the ageing process. Increasing evidence demonstrate that iron accumulation in selective regions of the brain may generate free radicals, thereby possessing implications for the etiology of neurodegenerative disorders. In a previous study we have reported that aged rats present recognition memory deficits.
View Article and Find Full Text PDFTopiramate is a new antiepileptic drug proposed to facilitate synaptic inhibition and block excitatory receptors. However, little is known about the effects of topiramate on memory. In the first experiment, intraperitoneal injection of topiramate at doses of 10.
View Article and Find Full Text PDF