Search results for "NEUROSCIENCE"

Cellular Response to Spinal Cord Injury in Regenerative and Non-Regenerative Stages in Xenopus Laevis

2020

Abstract Background The efficient regenerative abilities at larvae stages followed by a non-regenerative response after metamorphosis in froglets makes Xenopus an ideal model organism to understand the cellular responses leading to spinal cord regeneration. Methods We compared the cellular response to spinal cord injury between the regenerative and non-regenerative stages of Xenopus laevis. For this analysis, we used electron microscopy, immunofluorescence and histological staining of the extracellular matrix. We generated two transgenic lines: i) the reporter line with the zebrafish GFAP regulatory regions driving the expression of EGFP, and ii) a cell specific inducible ablation line with…

Dyadic Wind of Change: New Approaches to Improve Biopsychological Stress Regulation in Patients with Dementia and Their Spousal Caregivers

2019

Patients with dementia (PWD) and their caregivers experience long-term stress, leading to accelerated disease progression and to stress-related morbidity. Previous research focused on intrapersonal biopsychological stress responses. Quite recently, dyadic interrelations between caregivers and PWD and their effects on stress and caregiver burden have received more attention, giving rise to dyadic intervention studies. However, while it is of importance to consider both the patient and the caregiver from a dyadic point of view, evaluation of these dyadic interventions considering underlying mechanisms is still lacking. We therefore extend the current literature on dyadic processes between PWD…

Correlation between octopaminergic signalling and foraging task specialisation in honeybees

2020

Regulation of pollen and nectar foraging in honeybees is linked to differences in the sensitivity to the reward. Octopamine (OA) participates in the processing of reward-related information in the bee brain, being a candidate to mediate and modulate the division of labour among pollen and nectar foragers. Here we tested the hypothesis that OA affects the resource preferences of foragers. We first investigated whether oral administration of OA is involved in the transition from nectar to pollen foraging. We quantified the percentage of OA-treated bees that switched from a sucrose solution to a pollen feeder when the sugar concentration was decreased experimentally. We also evaluated if feedi…

Circadian Rhythm Variations and Nutrition in Children

2018

AbstractCircadian rhythms are the changes in biological processes that occur on a daily basis. Among these processes are reactions involved in metabolic homeostasis. Circadian rhythms are structured by the central clock in the suprachiasmatic nucleus of the hypothalamus via the control of melatonin expression. Circadian rhythms are also controlled by the peripheral clocks, which are intracellular mechanisms composed of the clock genes, whose expression follows a circadian pattern. Circadian rhythms are impacted by signals from the environment called zeitgebers, or time givers, which include light exposure, feeding schedule and composition, sleeping schedule and pattern, temperature, and phy…

Hyperforin Potentiates Antidepressant-Like Activity of Lanicemine in Mice

2018

International audience; N-methyl-D-aspartate receptor (NMDAR) modulators induce rapid and sustained antidepressant like-activity in rodents through a molecular mechanism of action that involves the activation of Ca2+ dependent signaling pathways. Moreover, ketamine, a global NMDAR antagonist is a potent, novel, and atypical drug that has been successfully used to treat major depressive disorder (MDD). However, because ketamine evokes unwanted side effects, alternative strategies have been developed for the treatment of depression. The objective of the present study was to determine the antidepressant effects of either a single dose of hyperforin or lanicemine vs. their combined effects in m…

Structure and Synaptic Function of Metal Binding to the Amyloid Precursor Protein and its Proteolytic Fragments

2017

Alzheimer’s disease (AD) is ultimately linked to the Amyloid Precursor Protein (APP). However, current research reveals an important synaptic function of APP and APP-like proteins (APLP1 and 2). In this context various neurotrophic and neuroprotective functions have been reported for the APP proteolytic fragments sAPPα, sAPPβ, and the monomeric amyloid-beta peptide (Aβ). APP is a metalloprotein and binds copper and zinc ions. Synaptic activity correlates with a release of these ions into the synaptic cleft and dysregulation of their homeostasis is linked to different neurodegenerative diseases. Metal binding to APP or its fragments affects its structure and its proteolytic cleavage and ther…

Parallels and differences between innate and adaptive lymphocytes.

2016

Lymphocytes are essential in innate and adaptive immunity. Recent insights suggest that some innate lymphocytes execute functions with adaptive characteristics, while adaptive lymphocytes can operate in ways reminiscent of innate cells. Rather than partitioning lymphocytes according to the type of effector function they execute, we propose that a relevant discrimination relates to the existence of conventional T cells in a naive state. The naive state can be seen as an actively repressed condition that supports T cell diversity and enables the flexible differentiation of effector cells in a manner that best addresses the antigenic challenge. We discuss these considerations in the context of…

Meningeal γδ T cell-derived IL-17 controls synaptic plasticity and short-term memory

2019

The notion of "immune privilege" of the brain has been revised to accommodate its infiltration, at steady state, by immune cells that participate in normal neurophysiology. However, the immune mechanisms that regulate learning and memory remain poorly understood. Here, we show that noninflammatory interleukin-17 (IL-17) derived from a previously unknown fetal-derived meningeal-resident γδ T cell subset promotes cognition. When tested in classical spatial learning paradigms, mice lacking γδ T cells or IL-17 displayed deficient short-term memory while retaining long-term memory. The plasticity of glutamatergic synapses was reduced in the absence of IL-17, resulting in impaired long-term poten…

Impact of Elastin-Derived Peptide VGVAPG on Matrix Metalloprotease-2 and -9 and the Tissue Inhibitor of Metalloproteinase-1, -2, -3 and -4 mRNA Expre…

2018

Degradation products of elastin, i.e. elastin-derived peptides (EDPs), are involved in various physiological and pathological processes. EDPs are detectable in cerebrospinal fluid in healthy people and in patients after ischemic stroke. However, to date, no studies concerning the role of EDP in the nervous system were conducted. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) play important roles during the repair phases of cerebral ischemia, particularly during angiogenesis and reestablishment of cerebral blood flow. Therefore, the aim of this study was to investigate the impact of the specific elastin-derived peptide VGVAPG on Mmp-2, -9 and Timp-1, -2,…

2018

The origin of spontaneous preference for dietary lipids in humans and rodents is debated, though recent compelling evidence has shown the existence of fat taste that might be considered a sixth taste quality. We investigated the implication of gustatory and reward brain circuits, triggered by linoleic acid (LA), a long-chain fatty acid. The LA was applied onto the circumvallate papillae for 30 min in conscious C57BL/6J mice, and neuronal activation was assessed using c-Fos immunohistochemistry. By using real-time reverse transcription polymerase chain reaction (RT-qPCR), we also studied the expression of mRNA encoding brain-derived neurotrophic factor (BDNF), Zif-268, and Glut-1 in some bra…