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https://www.readbyqxmd.com/read/28098899/analysis-of-gene-expression-profiles-of-non-small-cell-lung-cancer-at-different-stages-reveals-significantly-altered-biological-functions-and-candidate-genes
#1
Jin Wang, Jianxiang Song, Zhengya Gao, Xudong Huo, Yajun Zhang, Wencai Wang, Jianwei Qi, Shiying Zheng
We attempt to dissect the pathology of non-small cell lung cancer (NSCLC) patients at different stages and discover the novel candidate genes. Microarray data (GSE21933) were retrieved from the Gene Expression Omnibus database. The differential expression profiles of lung tumor tissues during different stages were analyzed. The significantly altered functions and pathways were assessed and the key nodes in a protein-protein interaction (PPI) network were screened out. Then, the coexpression gene pairs and tumor-related genes were assessed...
January 17, 2017: Oncology Reports
https://www.readbyqxmd.com/read/28097513/stable-control-of-firing-rate-mean-and-variance-by-dual-homeostatic-mechanisms
#2
Jonathan Cannon, Paul Miller
Homeostatic processes that provide negative feedback to regulate neuronal firing rates are essential for normal brain function. Indeed, multiple parameters of individual neurons, including the scale of afferent synapse strengths and the densities of specific ion channels, have been observed to change on homeostatic time scales to oppose the effects of chronic changes in synaptic input. This raises the question of whether these processes are controlled by a single slow feedback variable or multiple slow variables...
December 2017: Journal of Mathematical Neuroscience
https://www.readbyqxmd.com/read/28096851/acetylcholinesterase-inhibitor-improves-learning-and-memory-impairment-induced-by-toxoplasma-gondii-infection
#3
Hossein Mahmoudvand, Vahid Sheibani, Hossein Keshavarz, Saeedeh Shojaee, Khadijeh Esmaeelpour, Naser Ziaali
BACKGROUND: Here, we established the mouse models of chronic toxoplasmosis by T. gondii Tehran strain to provide a good understanding about defining the possible association between T. gondii exposure and learning and memory impairments. Moreover, as secondary objective of the present study, we hypothesized whether administration of an acetylcholinesterase (AChE) inhibitor could reduce learning and memory impairments induced by T. gondii infection. METHODS: Twenty-four male BALB/c mice were used to establishment of latent toxoplasmosis...
April 2016: Iranian Journal of Parasitology
https://www.readbyqxmd.com/read/28096497/bdnf-regains-function-in-hippocampal-long-term-potentiation-deficits-caused-by-diencephalic-damage
#4
Lindsey C Vedder, Lisa M Savage
Thiamine deficiency (TD), commonly associated with chronic alcoholism, leads to diencephalic damage, hippocampal dysfunction, and spatial learning and memory deficits. We show a decrease in the magnitude of long-term potentiation (LTP) and paired-pulse facilitation (PPF) at CA3-CA1 synapses, independent of sex, following diencephalic damage induced by TD in rats. Thus, despite a lack of extensive hippocampal cell loss, diencephalic brain damage down-regulates plastic processes within the hippocampus, likely contributing to impaired hippocampal-dependent behaviors...
February 2017: Learning & Memory
https://www.readbyqxmd.com/read/28095309/microglia-under-psychosocial-stressors-along-the-aging-trajectory-consequences-on-neuronal-circuits-behavior-and-brain-diseases
#5
Li Tian, Chin Wai Hui, Kanchan Bisht, Yunlong Tan, Kaushik Sharma, Song Chen, Xiangyang Zhang, Marie-Eve Tremblay
Mounting evidence indicates the importance of microglia for proper brain development and function, as well as in complex stress-related neuropsychiatric disorders and cognitive decline along the aging trajectory. Considering that microglia are resident immune cells of the brain, a homeostatic maintenance of their effector functions that impact neuronal circuitry, such as phagocytosis and secretion of inflammatory factors, is critical to prevent the onset and progression of these pathological conditions. However, the molecular mechanisms by which microglial functions can be properly regulated under healthy and pathological conditions are still largely unknown...
January 14, 2017: Progress in Neuro-psychopharmacology & Biological Psychiatry
https://www.readbyqxmd.com/read/28095201/multisensory-bayesian-inference-depends-on-synapse-maturation-during-training-theoretical-analysis-and-neural-modeling-implementation
#6
Mauro Ursino, Cristiano Cuppini, Elisa Magosso
Recent theoretical and experimental studies suggest that in multisensory conditions, the brain performs a near-optimal Bayesian estimate of external events, giving more weight to the more reliable stimuli. However, the neural mechanisms responsible for this behavior, and its progressive maturation in a multisensory environment, are still insufficiently understood. The aim of this letter is to analyze this problem with a neural network model of audiovisual integration, based on probabilistic population coding-the idea that a population of neurons can encode probability functions to perform Bayesian inference...
January 17, 2017: Neural Computation
https://www.readbyqxmd.com/read/28095195/deep-learning-with-dynamic-spiking-neurons-and-fixed-feedback-weights
#7
Arash Samadi, Timothy P Lillicrap, Douglas B Tweed
Recent work in computer science has shown the power of deep learning driven by the backpropagation algorithm in networks of artificial neurons. But real neurons in the brain are different from most of these artificial ones in at least three crucial ways: they emit spikes rather than graded outputs, their inputs and outputs are related dynamically rather than by piecewise-smooth functions, and they have no known way to coordinate arrays of synapses in separate forward and feedback pathways so that they change simultaneously and identically, as they do in backpropagation...
January 17, 2017: Neural Computation
https://www.readbyqxmd.com/read/28094782/cocaine-enhances-dc-to-t-cell-hiv-1-transmission-by-activating-dc-sign-larg-lsp1-complex-and-facilitating-infectious-synapse-formation
#8
Anil Prasad, Rutuja Kulkarni, Shuxian Jiang, Jerome E Groopman
DC-SIGN is a dendritic cell surface structure which participates in binding and transmission of HIV-1. Here, for the first time we demonstrate that cocaine induces over expression of DC-SIGN and significantly enhances virus transfer from DCs to T-cells by increasing the binding and internalization of HIV-1 in DCs. We found that cocaine activates a DC-SIGN mediated 'signalosome' complex by enhancing its association with LARG and LSP1. Further, LARG was observed to participate in DC-SIGN mediated internalization of HIV-1 in DCs...
January 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28093559/gradation-approx-10-size-states-of-synaptic-strength-by-quantal-addition-of-structural-modules
#9
Kang K L Liu, Michael F Hagan, John E Lisman
Memory storage involves activity-dependent strengthening of synaptic transmission, a process termed long-term potentiation (LTP). The late phase of LTP is thought to encode long-term memory and involves structural processes that enlarge the synapse. Hence, understanding how synapse size is graded provides fundamental information about the information storage capability of synapses. Recent work using electron microscopy (EM) to quantify synapse dimensions has suggested that synapses may structurally encode as many as 26 functionally distinct states, which correspond to a series of proportionally spaced synapse sizes...
March 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28093558/glutamatergic-synapses-are-structurally-and-biochemically-complex-because-of-multiple-plasticity-processes-long-term-potentiation-long-term-depression-short-term-potentiation-and-scaling
#10
REVIEW
John Lisman
Synapses are complex because they perform multiple functions, including at least six mechanistically different forms of plasticity. Here, I comment on recent developments regarding these processes. (i) Short-term potentiation (STP), a Hebbian process that requires small amounts of synaptic input, appears to make strong contributions to some forms of working memory. (ii) The rules for long-term potentiation (LTP) induction in CA3 have been clarified: induction does not depend obligatorily on backpropagating sodium spikes but, rather, on dendritic branch-specific N-methyl-d-aspartate (NMDA) spikes...
March 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28093557/hebbian-plasticity-requires-compensatory-processes-on-multiple-timescales
#11
REVIEW
Friedemann Zenke, Wulfram Gerstner
We review a body of theoretical and experimental research on Hebbian and homeostatic plasticity, starting from a puzzling observation: while homeostasis of synapses found in experiments is a slow compensatory process, most mathematical models of synaptic plasticity use rapid compensatory processes (RCPs). Even worse, with the slow homeostatic plasticity reported in experiments, simulations of existing plasticity models cannot maintain network stability unless further control mechanisms are implemented. To solve this paradox, we suggest that in addition to slow forms of homeostatic plasticity there are RCPs which stabilize synaptic plasticity on short timescales...
March 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28093550/experience-dependent-homeostasis-of-noise-at-inhibitory-synapses-preserves-information-coding-in-adult-visual-cortex
#12
Ming Gao, Jessica L Whitt, Shiyong Huang, Angela Lee, Stefan Mihalas, Alfredo Kirkwood, Hey-Kyoung Lee
Synapses are intrinsically 'noisy' in that neurotransmitter is occasionally released in the absence of an action potential. At inhibitory synapses, the frequency of action potential-independent release is orders of magnitude higher than that at excitatory synapses raising speculations that it may serve a function. Here we report that the frequency of action potential-independent inhibitory synaptic 'noise' (i.e. miniature inhibitory postsynaptic currents, mIPSCs) is highly regulated by sensory experience in visual cortex...
March 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28093548/astrocytic-control-of-synaptic-function
#13
REVIEW
Thomas Papouin, Jaclyn Dunphy, Michaela Tolman, Jeannine C Foley, Philip G Haydon
Astrocytes intimately interact with synapses, both morphologically and, as evidenced in the past 20 years, at the functional level. Ultrathin astrocytic processes contact and sometimes enwrap the synaptic elements, sense synaptic transmission and shape or alter the synaptic signal by releasing signalling molecules. Yet, the consequences of such interactions in terms of information processing in the brain remain very elusive. This is largely due to two major constraints: (i) the exquisitely complex, dynamic and ultrathin nature of distal astrocytic processes that renders their investigation highly challenging and (ii) our lack of understanding of how information is encoded by local and global fluctuations of intracellular calcium concentrations in astrocytes...
March 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28093546/time-course-and-mechanisms-of-homeostatic-plasticity-in-layers-2-3-and-5-of-the-barrel-cortex
#14
Stanislaw Glazewski, Stuart Greenhill, Kevin Fox
Recent studies have shown that ocular dominance plasticity in layer 2/3 of the visual cortex exhibits a form of homeostatic plasticity that is related to synaptic scaling and depends on TNFα. In this study, we tested whether a similar form of plasticity was present in layer 2/3 of the barrel cortex and, therefore, whether the mechanism was likely to be a general property of cortical neurons. We found that whisker deprivation could induce homeostatic plasticity in layer 2/3 of barrel cortex, but not in a mouse strain lacking synaptic scaling...
March 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28093479/paired-stimulation-for-spike-timing-dependent-plasticity-in-primate-sensorimotor-cortex
#15
Stephanie C Seeman, Brian J Mogen, Eberhard E Fetz, Steve I Perlmutter
: Classic studies in vitro have described spike-timing dependent plasticity (STDP) at a synapse: the connection from neuron A to neuron B is strengthened (or weakened) when A fires before (or after) B within an optimal time window. Accordingly, more recent in vivo works have demonstrated behavioral effects consistent with an STDP mechanism; however many relied on single-unit recordings. The ability to modify cortical connections becomes useful in the context of injury when connectivity, and associated behavior, is compromised...
January 16, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28093473/differential-regulation-of-nmda-receptor-mediated-transmission-by-sk-channels-underlies-dorsal-ventral-differences-in-dynamics-of-schaffer-collateral-synaptic-function
#16
Walter E Babiec, Shekib A Jami, Ryan Guglietta, Patrick B Chen, Thomas J O'Dell
: Behavioral, physiological, and anatomical evidence indicates that the dorsal and ventral zones of the hippocampus have distinct roles in cognition. How the unique functions of these zones might depend on differences in synaptic and neuronal function arising from the strikingly different gene expression profiles exhibited by dorsal and ventral CA1 pyramidal cells is unclear. To begin to address this question, we investigated the mechanisms underlying differences in synaptic transmission and plasticity at dorsal and ventral Schaffer collateral (SC) synapses in the mouse hippocampus...
January 16, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28092659/rem-sleep-selectively-prunes-and-maintains-new-synapses-in-development-and-learning
#17
Wei Li, Lei Ma, Guang Yang, Wen-Biao Gan
The functions and underlying mechanisms of rapid eye movement (REM) sleep remain unclear. Here we show that REM sleep prunes newly formed postsynaptic dendritic spines of layer 5 pyramidal neurons in the mouse motor cortex during development and motor learning. This REM sleep-dependent elimination of new spines facilitates subsequent spine formation during development and when a new motor task is learned, indicating a role for REM sleep in pruning to balance the number of new spines formed over time. Moreover, REM sleep also strengthens and maintains newly formed spines, which are critical for neuronal circuit development and behavioral improvement after learning...
January 16, 2017: Nature Neuroscience
https://www.readbyqxmd.com/read/28091578/temporal-dynamics-of-cerebellar-and-motor-cortex-physiological-processes-during-motor-skill-learning
#18
D Spampinato, P Celnik
Learning motor tasks involves distinct physiological processes in the cerebellum (CB) and primary motor cortex (M1). Previous studies have shown that motor learning results in at least two important neurophysiological changes: modulation of cerebellar output mediated in-part by long-term depression of parallel fiber-Purkinje cell synapse and induction of long-term plasticity (LTP) in M1, leading to transient occlusion of additional LTP-like plasticity. However, little is known about the temporal dynamics of these two physiological mechanisms during motor skill learning...
January 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28090790/loss-of-interneuron-derived-collagen-xix-leads-to-a-reduction-in-perineuronal-nets-in-the-mammalian-telencephalon
#19
Jianmin Su, James Cole, Michael A Fox
Perineuronal nets (PNNs) are lattice-like supramolecular assemblies of extracellular glycoproteins that surround subsets of neuronal cell bodies in the mammalian telencephalon. PNNs emerge at the end of the critical period of brain development, limit neuronal plasticity in the adult brain, and are lost in a variety of complex brain disorders diseases, including schizophrenia. The link between PNNs and schizophrenia led us to question whether neuronally expressed extracellular matrix (ECM) molecules associated with schizophrenia contribute to the assembly of these specialized supramolecular ECM assemblies...
February 2017: ASN Neuro
https://www.readbyqxmd.com/read/28089576/conditional-deletion-of-pejvakin-in-adult-outer-hair-cells-causes-progressive-hearing-loss-in-mice
#20
Suzan L Harris, Marcin Kazmierczak, Tina Pangršič, Prahar Shah, Nadiya Chuchvara, Alonso Barrantes-Freer, Tobias Moser, Martin Schwander
Mutations in the Pejvakin (Pjvk) gene cause autosomal recessive hearing loss DFNB59 with audiological features of auditory neuropathy spectrum disorder (ANSD) or cochlear dysfunction. The precise mechanisms underlying the variable clinical phenotypes of DFNB59 remain unclear. Here, we demonstrate that mice with conditional ablation of the Pjvk gene in all sensory hair cells or only in outer hair cells (OHCs) show similar auditory phenotypes with early-onset profound hearing loss. By contrast, loss of Pjvk in adult OHCs causes a slowly progressive hearing loss associated with OHC degeneration and delayed loss of inner hair cells (IHCs), indicating a primary role for pejvakin in regulating OHC function and survival...
January 9, 2017: Neuroscience
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