Search results for "Neuron"
showing 10 items of 2611 documents
L’olfaction dans les troubles dépressifs : intérêts et perspectives
2017
International audience; Research on sensorial interactions with psychiatric diseases and particularly with the depressive syndrome has mainly focused on visual or auditory processes and much less on olfaction. The depressive illness is one of the most frequent psychiatric diagnoses in the community, with approximately one in five women and one in eight men experiencing a major depressive episode during their lifetime. Although genetic, epigenetic, neuroanatomical, neurochemical, neuroendocrinological and neuroimmunological changes can be detected during depression, the etiology of depression remains partly unclear. The current explanatory models are based on two main factors, i.e. pharmacol…
Identification of accessory olfactory system and medial amygdala in the zebrafish
2017
AbstractZebrafish larvae imprint on visual and olfactory cues of their kin on day 5 and 6 postfertilization, respectively. Only imprinted (but not non-imprinted) larvae show strongly activated crypt (and some microvillous) cells demonstrated by pERK levels after subsequent exposure to kin odor. Here, we investigate the olfactory bulb of zebrafish larvae for activated neurons located at the sole glomerulus mdG2 which receives crypt cell input. Imprinted larvae show a significantly increased activation of olfactory bulb cells compared to non-imprinted larvae after exposure to kin odor. Surprisingly, pERK activated Orthopedia-positive cell numbers in the intermediate ventral telencephalic nucl…
Stimulus Driven Functional Transformations in the Early Olfactory System.
2021
Olfactory stimuli are encountered across a wide range of odor concentrations in natural environments. Defining the neural computations that support concentration invariant odor perception, odor discrimination, and odor-background segmentation across a wide range of stimulus intensities remains an open question in the field. In principle, adaptation could allow the olfactory system to adjust sensory representations to the current stimulus conditions, a well-known process in other sensory systems. However, surprisingly little is known about how adaptation changes olfactory representations and affects perception. Here we review the current understanding of how adaptation impacts processing in …
High Fructose Diet inducing diabetes rapidly impacts olfactory epithelium and behavior in mice
2016
AbstractType 2 Diabetes (T2D), a major public health issue reaching worldwide epidemic, has been correlated with lower olfactory abilities in humans. As olfaction represents a major component of feeding behavior, its alteration may have drastic consequences on feeding behaviors that may in turn aggravates T2D. In order to decipher the impact of T2D on the olfactory epithelium, we fed mice with a high fructose diet (HFruD) inducing early diabetic state in 4 to 8 weeks. After only 4 weeks of this diet, mice exhibited a dramatic decrease in olfactory behavioral capacities. Consistently, this decline in olfactory behavior was correlated to decreased electrophysiological responses of olfactory n…
Protein misfolding, amyotrophic lateral sclerosis and guanabenz: Protocol for a phase II RCT with futility design (ProMISe trial)
2017
IntroductionRecent studies suggest that endoplasmic reticulum stress may play a critical role in the pathogenesis of amyotrophic lateral sclerosis (ALS) through an altered regulation of the proteostasis, the cellular pathway-balancing protein synthesis and degradation. A key mechanism is thought to be the dephosphorylation of eIF2α, a factor involved in the initiation of protein translation. Guanabenz is an alpha-2-adrenergic receptor agonist safely used in past to treat mild hypertension and is now an orphan drug. A pharmacological action recently discovered is its ability to modulate the synthesis of proteins by the activation of translational factors preventing misfolded protein accumula…
Optogenetics: a new method for the causal analysis of neuronal networks in vivo
2012
Abstract The causal analysis of neuronal network function requires selective manipulations of genetically defined neuronal subpopulations in the intact living brain. Here, we highlight the method of optogenetics, which meets those needs. We cover methodological aspects, limitations, and practical applications in the field of neurosciences. The fundamentals of optogenetics are light-sensitive transmembrane channels and light-driven ion pumps, which can be genetically encoded, without requiring the application of exogenous cofactors. These opsins are expressed in neurons by means of viral gene transfer and cell-specific promoters. Light for stimulation can be non- or minimally invasively de…
Pain-Induced Negative Affect Is Mediated via Recruitment of The Nucleus Accumbens Kappa Opioid System.
2019
Negative affective states affect quality of life for patients suffering from pain. These maladaptive emotional states can lead to involuntary opioid overdose and many neuropsychiatric comorbidities. Uncovering the mechanisms responsible for pain-induced negative affect is critical in addressing these comorbid outcomes. The nucleus accumbens (NAc) shell, which integrates the aversive and rewarding valence of stimuli, exhibits plastic adaptations in the presence of pain. In discrete regions of the NAc, activation of the kappa opioid receptor (KOR) decreases the reinforcing properties of rewards and induces aversive behaviors. Using complementary techniques, we report that in vivo recruitment …
Fasciola spp: Mapping of the MF6 epitope and antigenic analysis of the MF6p/HDM family of heme-binding proteins
2017
MF6p/FhHDM-1 is a small cationic heme-binding protein which is recognized by the monoclonal antibody (mAb) MF6, and abundantly present in parenchymal cells and secreted antigens of Fasciola hepatica. Orthologs of this protein (MF6p/HDMs) also exist in other causal agents of important foodborne trematodiasis, such as Clonorchis sinensis, Opisthorchis viverrini and Paragonimus westermani. Considering that MF6p/FhHDM-1 is relevant for heme homeostasis in Fasciola and was reported to have immunomodulatory properties, this protein is expected to be a useful target for vaccination. Thus, in this study we mapped the epitope recognized by mAb MF6 and evaluated its antigenicity in sheep. The sequenc…
Assessing the Impact of Single-Cell Stimulation on Local Networks in Rat Barrel Cortex—A Feasibility Study
2019
In contrast to the long-standing notion that the role of individual neurons in population activity is vanishingly small, recent studies have shown that electrical activation of only a single cortical neuron can have measurable effects on global brain state, movement, and perception. Although highly important for understanding how neuronal activity in cortex is orchestrated, the cellular and network mechanisms underlying this phenomenon are unresolved. Here, we first briefly review the current state of knowledge regarding the phenomenon of single-cell induced network modulation and discuss possible underpinnings. Secondly, we show proof of principle for an experimental approach to elucidate …
Acute Cortical Transhemispheric Diaschisis after Unilateral Traumatic Brain Injury
2017
Focal neocortical brain injuries lead to functional alterations, which can spread beyond lesion-neighboring brain areas. The undamaged hemisphere and its associated disturbances after a unilateral lesion, so-called transhemispheric diaschisis, have been progressively disclosed over the last decades; they are strongly involved in the pathophysiology and, potentially, recovery of brain injuries. Understanding the temporal dynamics of these transhemispheric functional changes is crucial to decipher the role of the undamaged cortex in the processes of functional reorganization at different stages post-lesion. In this regard, little is known about the acute-subacute processes after 24-48 h in th…