Search results for "campus"
showing 10 items of 667 documents
Functional implications of hippocampal volume and diffusivity in mild cognitive impairment.
2005
Abstract Hippocampal atrophy has been related to mild cognitive impairment (MCI) and early Alzheimer disease (AD), but the diagnostic significance of cross-sectionally determined hippocampal volumes is still ambiguous. Diffusion-Tensor-Imaging (DTI) in MCI patients revealed an association of microstructural changes in hippocampal areas with verbal memory decline. MRI volumetry and DTI were combined to investigate 18 MCI patients attending a memory clinic, and 18 carefully age- and gender-matched healthy controls. Neuropsychological testing, high resolution T1-weighted volume MRI scans, and DTI scans with regions-of-interest in hippocampal areas were applied. Left hippocampal volume was sign…
Altered expression of neuropeptides in the primary somatosensory cortex of the Down syndrome model Ts65Dn.
2011
Down syndrome is the most common genetic disorder associated with mental retardation. Subjects and mice models for Down syndrome (such as Ts65Dn) show defects in the formation of neuronal networks in both the hippocampus and the cerebral cortex. The principal neurons display alterations in the morphology, density and distribution of dendritic spines in the cortex as well as in the hippocampus. Several evidences point to the possibility that the atrophy observed in principal neurons could be mediated by changes in their inhibitory inputs and, in fact, an imbalance between excitation and inhibition has been observed in Ts65Dn mice in these regions, which are crucial for learning and informati…
Adolescent binge‐ethanol accelerates cognitive impairment and β‐amyloid production and dysregulates endocannabinoid signaling in the hippocampus of A…
2019
Previous research in rodents suggests that the long‐term neurobehavioral disturbances induced by chronic ethanol (EtOH) exposure could be due to endocannabinoid system (ECS) alterations. Moreover, ECS failure has been proposed to mediate the cognitive impairment and β‐amyloid production in Alzheimer disease (AD). Thus, in the present study, we evaluated the effects of adolescent EtOH binge drinking on the cognitive disturbances, hippocampal β‐amyloid levels, and in the ECS expression on a transgenic mouse model (APP/PSEN, AZ) of AD. We exposed AZ and wild‐type mice to a binge‐drinking treatment during adolescence. At 6 and 12 months of age, we evaluated hippocampal‐dependent learning and me…
Nitric oxide and glutamate interaction in the control of cortical and hippocampal excitability.
1999
Summary: Purpose: We investigated the role of nitric oxide (NO) as a new neurotransmitter in the control of excitability of the hippocampus and the cerebral cortex, as well as the possible functional interaction between NO and the glutamate systems. Methods: The experiments were performed on anesthetized rats. The bioelectrical activities of the somatosensory cortex and the CA1 region of the hippocampus of these rats were recorded. Pharmacologic inhibition of NO synthase (NOS) through the nonselective and brain-selective inhibitors, N-nitro-L-arginine methyl ester (l-NAME) and 7-nitroindazole (7-NI), was performed. Results: The treatments caused the appearance of an interictal discharge act…
Role of dopamine neurotransmission in the long-term effects of repeated social defeat on the conditioned rewarding effects of cocaine
2016
Numerous studies report that social defeat stress alters dopamine (DA) neurotransmission in several areas of the brain. Alterations of the mesolimbic dopaminergic pathway are believed to be responsible for the increased vulnerability to drug use observed as a result of social stress. In the present study, we evaluated the influence of DA receptors on the long-term effect of repeated social defeat (RSD) on the conditioned rewarding and reinstating effects of cocaine. For this purpose, the D1R antagonist SCH 23390 and the D1R antagonist raclopride were administered 30 min before each social defeat and a cocaine-induced CPP procedure was initiated three weeks later. The expression of the D1R a…
Lasting downregulation of the lipid peroxidation enzymes in the prefrontal cortex of mice susceptible to stress-induced anhedonia
2015
International audience; Antioxidant enzymes and lipid peroxidation in the brain are involved in neuropsychiatric pathologies, including depression. 14- or 28-day chronic stress model induced a depressive syndrome defined by lowered reward sensitivity in C57BL/6J mice and changed gene expression of peroxidation enzymes as shown in microarray assays. We studied how susceptibility or resilience to anhedonia is related to lipid peroxidation in the prefrontal cortex (PFC). With 14-day stress, a comparison of the activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX) and accumulation of malondialdehyde (MDA) revealed a decrease of the first two measures in suscepti…
Short-term ischemia usually used for ischemic preconditioning causes loss of dendritic integrity after long-term survival in the gerbil hippocampus
2006
Ischemic preconditioning has been established as a powerful experimental neuroprotective strategy, both after global and focal cerebral ischemia. Little is known, however, about the structural and functional long-term outcome. Therefore, our present study was designed to check for potential subtle alterations in the hippocampus after long-term survival. Gerbils were subjected either to short-term ischemia of 2.5 min duration usually used for ischemic preconditioning (n=8) or to sham operation (n=6) and allowed to survive for 6 weeks. Hippocampi with neuronal densities comparable to those of sham-operated control animals were analyzed for dendritic marker proteins MAP2, MAP1B and synaptopodi…
Gender-dependent behavioural impairment and brain metabolites in young adult rats after short term exposure to lead acetate
2012
We investigated the behavioural effects of short-term lead (Pb) exposure in adult rats producing blood Pb concentration (<10. μg/dL) below those associated with neurological impairment in occupationally exposed individuals. In order to assess gender differences, we performed parallel behavioural experiments in male and female rats. Exposure to Pb acetate (50. mg/L in drinking water) for 30-45 days induced behavioural alterations consisting in hyperactivity in a novel environment and impairment of spatial memory. These effects were observed only in male rats. Object recognition, motor coordination were unaffected by Pb exposure. Magnetic resonance spectroscopy allows . in vivo assessment of …
Acute stress does not impair long-term memory retrieval in older people.
2013
Previous studies have shown that stress-induced cortisol increases impair memory retrieval in young people. This effect has not been studied in older people; however, some findings suggest that age-related changes in the brain can affect the relationships between acute stress, cortisol and memory in older people. Our aim was to investigate the effects of acute stress on long-term memory retrieval in healthy older people. To this end, 76 participants from 56 to 76 years old (38 men and 38 women) were exposed to an acute psychosocial stressor or a control task. After the stress/control task, the recall of pictures, words and stories learned the previous day was assessed. There were no differe…
Environmental enrichment promotes neurogenesis and changes the extracellular concentrations of glutamate and GABA in the hippocampus of aged rats.
2005
The aim of the present study was to investigate the effects of environmental enrichment on the neurogenesis and the extracellular concentrations of glutamate and GABA in the hippocampus of freely moving young and aged rats. Male Wistar rats of 2 (young) and 25 (old) months of age were housed during 8 weeks in an enriched environment; control rats were kept in individual plastic cages during that same period of time. Rats were injected intraperitoneally with bromodeoxyuridine (BrdU; 40 mg/kg; 7 days) during the fourth week of the housing period to detect neurogenesis in the dentate gyrus (DG) of the hippocampus. Rats were sacrified 6 weeks after the last injection of BrdU. During the last we…