Search results for "nap"
showing 10 items of 2226 documents
Chronic hyponatremia in a patient with renal salt wasting and without cerebral disease: relationship between RSW, risk of fractures and cognitive imp…
2018
Renal salt wasting syndrome (RSW) is defined as a renal loss of sodium leading to hyponatremia and a decrease in extracellular fluid volume (ECV). Differentiation of this disorder from the syndrome of inappropriate antidiuretic hormone secretion (SIADH), a common cause of hyponatremia, can be difficult because both can present with hyponatremia and concentrated urine with natriuresis. Our clinical case about a 78-year-old woman with a recent fracture of the right femur not only confirms that this syndrome can occur in patients without intracranial pathologies (CT documented), but depicts how the hyponatremia caused by RSW can show a chronic, oscillating course. This is an interesting point …
Mastocytosis - pathogenesis, clinical manifestation and treatment
2017
The term mastocytosis designates a group of rare disorders characterized by typical skin lesions, frequently associated episodes of anaphylaxis, and clinical symptoms related to the release of various mediators. Dermatologists/allergists are frequently the first to establish the diagnosis. The condition is based on clonal mast cell proliferation, usually in the skin or bone marrow and only rarely in the gastrointestinal tract or other tissues. In general, mastocytosis has a good prognosis in terms of life expectancy. Rare variants - including mast cell leukemia, aggressive mastocytosis, and the exceedingly rare mast cell sarcoma - require cytoreductive therapy. In cases associated with hema…
Altered synaptic phospholipid signaling in PRG-1 deficient mice induces exploratory behavior and motor hyperactivity resembling psychiatric disorders.
2017
Abstract Plasticity related gene 1 (PRG-1) is a neuron specific membrane protein located at the postsynaptic density of glutamatergic synapses. PRG-1 modulates signaling pathways of phosphorylated lipid substrates such as lysophosphatidic acid (LPA). Deletion of PRG-1 increases presynaptic glutamate release probability leading to neuronal over-excitation. However, due to its cortical expression, PRG-1 deficiency leading to increased glutamatergic transmission is supposed to also affect motor pathways. We therefore analyzed the effects of PRG-1 function on exploratory and motor behavior using homozygous PRG-1 knockout (PRG-1−/−) mice and PRG-1/LPA2–receptor double knockout (PRG-1−/−/LPA2−/−)…
NT-3 protein levels are enhanced in the hippocampus of PRG1-deficient mice but remain unchanged in PRG1/LPA2 double mutants
2015
The plasticity-related gene 1 (PRG1) modulates bioactive lipids at the postsynaptic density and is a novel player in neuronal plasticity and regulation of glutamatergic transmission at principal neurons. PRG1, a neuronal molecule, is highly expressed during development and regeneration processes at the postsynaptic density, modulates synaptic lysophosphatidic acid (LPA) levels and is related to epilepsy and brain injury. In the present study, we analyzed the interaction between the synaptic molecules PRG1 and LPA2R with other plasticity-related molecules the neurotrophins. The protein levels of NGF, BDNF and NT-3 were measured using ELISA in hippocampal tissue of homozygous (PRG(-/-)) and h…
Lack of Hypothalamus Polysialylation Inducibility Correlates With Maladaptive Eating Behaviors and Predisposition to Obesity
2018
This original research article (6 p.) is part of the research topic . Specialty section: This article was submitted to Neuroenergetics, Nutrition and Brain Health, a section of the journal Frontiers in Nutrition.; International audience; High variability exists in individual susceptibility to develop overweight in an obesogenic environment and the biological underpinnings of this heterogeneity are poorly understood. In this brief report, we show in mice that the vulnerability to diet-induced obesity is associated with low level of polysialic acid-neural cell adhesion molecule (PSA-NCAM), a factor of neural plasticity, in the hypothalamus. As we previously shown that reduction of hypothalami…
Modulation of Neocortical Development by Early Neuronal Activity: Physiology and Pathophysiology.
2017
Animal and human studies revealed that patterned neuronal activity is an inherent feature of developing nervous systems. This review summarizes our current knowledge about the mechanisms generating early electrical activity patterns and their impact on structural and functional development of the cerebral cortex. All neocortical areas display distinct spontaneous and sensory-driven neuronal activity patterns already at early phases of development. At embryonic stages, intermittent spontaneous activity is synchronized within small neuronal networks, becoming more complex with further development. This transition is accompanied by a gradual shift from electrical to chemical synaptic transmiss…
A Perspective : Active Role of Lipids in Neurotransmitter Dynamics
2019
AbstractSynaptic neurotransmission is generally considered as a function of membrane-embedded receptors and ion channels in response to the neurotransmitter (NT) release and binding. This perspective aims to widen the protein-centric view by including another vital component—the synaptic membrane—in the discussion. A vast set of atomistic molecular dynamics simulations and biophysical experiments indicate that NTs are divided into membrane-binding and membrane-nonbinding categories. The binary choice takes place at the water-membrane interface and follows closely the positioning of the receptors’ binding sites in relation to the membrane. Accordingly, when a lipophilic NT is on route to a m…
Modulation of Hippocampal Circuits by Muscarinic and Nicotinic Receptors
2017
This article provides a review of the effects of activation of muscarinic and nicotinic receptors on the physiological properties of circuits in the hippocampal formation. Previous articles have described detailed computational hypotheses about the role of cholinergic neuromodulation in enhancing the dynamics for encoding in cortical structures and the role of reduced cholinergic modulation in allowing consolidation of previously encoded information. This article will focus on addressing the broad scope of different modulatory effects observed within hippocampal circuits, highlighting the heterogeneity of cholinergic modulation in terms of the physiological effects of activation of muscarin…
More than a pore: How voltage-gated calcium channels act on different levels of neuronal communication regulation.
2021
ABSTRACT Voltage-gated calcium channels (VGCCs) represent key regulators of the calcium influx through the plasma membrane of excitable cells, like neurons. Activated by the depolarization of the membrane, the opening of VGCCs induces very transient and local changes in the intracellular calcium concentration, known as calcium nanodomains, that in turn trigger calcium-dependent signaling cascades and the release of chemical neurotransmitters. Based on their central importance as concierges of excitation-secretion coupling and therefore neuronal communication, VGCCs have been studied in multiple aspects of neuronal function and malfunction. However, studies on molecular interaction partners …
Cortical network mechanisms of response inhibition
2020
SummaryBoth the right inferior frontal gyrus (rIFG) and the pre-supplementary motor area (pre-SMA) are crucial for successful response inhibition. However, the particular functional roles of those two regions have been controversially debated for more than a decade now. It is unclear whether the rIFG directly initiates stopping or serves an attentional function, whereas the stopping is triggered by the pre-SMA. The current multimodal MEG/fMRI study sought to clarify the role and temporal activation order of both regions in response inhibition using a selective stopping task. This task dissociates inhibitory from attentional processes. Our results reliably reveal a temporal precedence of rIF…