Read by QxMD icon Read

Memory mechanisms

Annekathrin Widmann, Marc Artinger, Lukas Biesinger, Kathrin Boepple, Christina Peters, Jana Schlechter, Mareike Selcho, Andreas S Thum
Memory formation is a highly complex and dynamic process. It consists of different phases, which depend on various neuronal and molecular mechanisms. In adult Drosophila it was shown that memory formation after aversive Pavlovian conditioning includes-besides other forms-a labile short-term component that consolidates within hours to a longer-lasting memory. Accordingly, memory formation requires the timely controlled action of different neuronal circuits, neurotransmitters, neuromodulators and molecules that were initially identified by classical forward genetic approaches...
October 2016: PLoS Genetics
Qian Cai, Prasad Tammineni
Alzheimer's disease (AD) is characterized by brain deposition of amyloid plaques and tau neurofibrillary tangles along with steady cognitive decline. Synaptic damage, an early pathological event, correlates strongly with cognitive deficits and memory loss. Mitochondria are essential organelles for synaptic function. Neurons utilize specialized mechanisms to drive mitochondrial trafficking to synapses in which mitochondria buffer Ca2+ and serve as local energy sources by supplying ATP to sustain neurotransmitter release...
October 20, 2016: Journal of Alzheimer's Disease: JAD
Nicole Mons, Daniel Beracochea
A prime mechanism that contributes to the development and maintenance of alcoholism is the dysregulation of the hypothalamic-pituitary-adrenal axis activity and the release of glucocorticoids (cortisol in humans and primates, corticosterone in rodents) from the adrenal glands. In the brain, sustained, local elevation of glucocorticoid concentration even long after cessation of chronic alcohol consumption compromises functional integrity of a circuit, including the prefrontal cortex (PFC), the hippocampus (HPC), and the amygdala (AMG)...
2016: Frontiers in Psychiatry
Jillian Iafrati, Arnaud Malvache, Cecilia Gonzalez Campo, M Juliana Orejarena, Olivier Lassalle, Lamine Bouamrane, Pascale Chavis
The postnatal maturation of the prefrontal cortex (PFC) represents a period of increased vulnerability to risk factors and emergence of neuropsychiatric disorders. To disambiguate the pathophysiological mechanisms contributing to these disorders, we revisited the endophenotype approach from a developmental viewpoint. The extracellular matrix protein reelin which contributes to cellular and network plasticity, is a risk factor for several psychiatric diseases. We mapped the aggregate effect of the RELN risk allele on postnatal development of PFC functions by cross-sectional synaptic and behavioral analysis of reelin-haploinsufficient mice...
October 21, 2016: Scientific Reports
Min-Soo Kim, Ji Hye Bang, Jun Lee, Jung-Soo Han, Tae Gon Baik, Won Kyung Jeon
BACKGROUND: Ginkgo biloba extract (GBE)-a widely used nutraceutical-is reported to have diverse functions, including positive effects on memory and vasodilatory properties. Although numerous studies have assessed the neuroprotective properties of GBE in ischemia, only a few studies have investigated the neuro-pharmacological mechanisms of action of GBE in chronic cerebral hypoperfusion (CCH). PURPOSE: In the present study, we sought to determine the effects of GBE on CCH-induced neuroinflammation and cholinergic dysfunction in a rat model of bilateral common carotid artery occlusion (BCCAo)...
November 15, 2016: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
Bruno Cessac, Arnaud Le Ny, Eva Löcherbach
We initiate a mathematical analysis of hidden effects induced by binning spike trains of neurons. Assuming that the original spike train has been generated by a discrete Markov process, we show that binning generates a stochastic process that is no longer Markov but is instead a variable-length Markov chain (VLMC) with unbounded memory. We also show that the law of the binned raster is a Gibbs measure in the DLR (Dobrushin-Lanford-Ruelle) sense coined in mathematical statistical mechanics. This allows the derivation of several important consequences on statistical properties of binned spike trains...
October 20, 2016: Neural Computation
Qian Qi, Mary M Cavanagh, Sabine Le Saux, Lisa E Wagar, Sally Mackey, Jinyu Hu, Holden Maecker, Gary E Swan, Mark M Davis, Cornelia L Dekker, Lu Tian, Cornelia M Weyand, Jörg J Goronzy
Vaccination with attenuated live varicella zoster virus (VZV) can prevent zoster reactivation, but protection is incomplete especially in an older population. To decipher the molecular mechanisms underlying variable vaccine responses, T- and B-cell responses to VZV vaccination were examined in individuals of different ages including identical twin pairs. Contrary to the induction of VZV-specific antibodies, antigen-specific T cell responses were significantly influenced by inherited factors. Diminished generation of long-lived memory T cells in older individuals was mainly caused by increased T cell loss after the peak response while the expansion of antigen-specific T cells was not affected by age...
October 2016: PLoS Pathogens
Neila Maria R de Lima, Emerson de O Ferreira, Mara Yone S D Fernandes, Francisco Arnaldo V de Lima, Kelly Rose T Neves, Marta Regina S do Carmo, Geanne M de Andrade
Inflammation plays a pivotal role in the development of ischemic brain damage. Astrocyte activation promotes the production of several proinflammatory mediators, such as TNF-α and iNOS. Eventually, neuronal death occurs, leading to the development of motor and memory deficits in patients. Boldine is the main alkaloid in the leaves and bark of the Peumus boldus Molina, and has anti-inflammatory and antioxidant properties. The aim of this work was to investigate the neuroprotective effect of boldine on neuroinflammation and memory deficits induced by permanent middle cerebral artery occlusion (pMCAO) in mice...
October 19, 2016: Behavioural Pharmacology
Naseem Jamnia, Janice H Urban, Grace Beth Stuzmann, Sarah Chiren, Emily Reisenbigler, Robert Marr, Daniel A Peterson, Dorothy A Kozlowski
Repeat concussions (RC) can result in significant long-term neurological consequences and increased risk for neurodegenerative disease compared to single concussion (SC). Mechanisms underlying this difference are poorly understood and best elucidated using an animal model. To the best of our knowledge, there is no closed-head model in the adult rat using a commercially available device. We developed a novel and clinically relevant closed-head injury (CHI) model of both single and multiple concussions in the adult rat using a controlled cortical impact (CCI) device...
October 20, 2016: Journal of Neurotrauma
Sven Dirkmann, Mirko Hansen, Martin Ziegler, Hermann Kohlstedt, Thomas Mussenbrock
In this work we report on the role of ion transport for the dynamic behavior of a double barrier quantum mechanical Al/Al2O3/NbxOy/Au memristive device based on numerical simulations in conjunction with experimental measurements. The device consists of an ultra-thin NbxOy solid state electrolyte between an Al2O3 tunnel barrier and a semiconductor metal interface at an Au electrode. It is shown that the device provides a number of interesting features such as an intrinsic current compliance, a relatively long retention time, and no need for an initialization step...
October 20, 2016: Scientific Reports
Hillary C Schiff, Joshua P Johansen, Mian Hou, David Ea Bush, Emily K Smith, JoAnna E Klein, Joseph E LeDoux, Robert M Sears
Memory formation requires the temporal coordination of molecular events and cellular processes following a learned event. During Pavlovian threat (fear) conditioning (PTC), sensory and neuromodulatory inputs converge on post-synaptic neurons within the lateral nucleus of the amygdala (LA). By activating an intracellular cascade of signaling molecules, these G-protein-coupled neuromodulatory receptors are capable of recruiting a diverse profile of plasticity-related proteins. Here we report that norepinephrine, through its actions on β-adrenergic receptors (βARs), modulates aversive memory formation following PTC through two molecularly and temporally distinct signaling mechanisms...
October 20, 2016: Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology
Laura Whitton, Donna Cosgrove, Christopher Clarkson, Denise Harold, Kimberley Kendall, Alex Richards, Kiran Mantripragada, Michael J Owen, Michael C O'Donovan, James Walters, Annette Hartmann, Betina Konte, Dan Rujescu, Michael Gill, Aiden Corvin, Stephen Rea, Gary Donohoe, Derek W Morris
Epigenetic mechanisms are an important heritable and dynamic means of regulating various genomic functions, including gene expression, to orchestrate brain development, adult neurogenesis, and synaptic plasticity. These processes when perturbed are thought to contribute to schizophrenia pathophysiology. A core feature of schizophrenia is cognitive dysfunction. For genetic disorders where cognitive impairment is more severe such as intellectual disability, there are a disproportionally high number of genes involved in the epigenetic regulation of gene transcription...
October 20, 2016: American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics
A Eraso-Pichot, R Larramona-Arcas, E Vicario-Orri, R Villalonga, L Pardo, E Galea, R Masgrau
Astrocytic excitability relies on cytosolic calcium increases as a key mechanism, whereby astrocytes contribute to synaptic transmission and hence learning and memory. While it is a cornerstone of neurosciences that experiences are remembered, because transmitters activate gene expression in neurons, long-term adaptive astrocyte plasticity has not been described. Here, we investigated whether the transcription factor CREB mediates adaptive plasticity-like phenomena in astrocytes. We found that activation of CREB-dependent transcription reduced the calcium responses induced by ATP, noradrenaline, or endothelin-1...
October 19, 2016: Cellular and Molecular Life Sciences: CMLS
Gary Tse, Sheung Ting Wong, Vivian Tse, Yee Ting Lee, Hiu Yu Lin, Jie Ming Yeo
Pre-existing heterogeneities present in cardiac tissue are essential for maintaining the normal electrical and mechanical functions of the heart. Exacerbation of such heterogeneities or the emergence of dynamic factors can produce repolarization alternans, which are beat-to-beat alternations in the action potential time course. Traditionally, this was explained by restitution, but additional factors, such as cardiac memory, calcium handling dynamics, refractory period restitution, and mechano-electric feedback, are increasingly recognized as the underlying causes...
October 2016: Journal of Arrhythmia
Shekhar Dethe, M Deepak, Amit Agarwal
BACKGROUND: Bacopa monnieri (L.) Wettst., commonly known as Brahmi, is renowned in Indian traditional system for its potent memory enhancing activity, which has been validated by various scientific studies. OBJECTIVE: The objective of this study was to understand the molecular mechanism of memory enhancing activity of BacoMind(®) (BM), a standardized extract of B. monnieri. MATERIALS AND METHODS: BM was screened in vitro in a panel of cell-free and receptor-transfected cell assays...
July 2016: Pharmacognosy Magazine
Margaret M Brosnahan, Emily J Silvela, Jessica Crumb, Donald C Miller, Hollis N Erb, Douglas F Antczak
Invasive trophoblast from Day-34 horse conceptuses survives in extra-uterine sites in allogeneic recipients that are immunologically naïve to donor major histocompatibility complex class I antigens. The ectopic trophoblast retains its in utero characteristics, including similar lifespan, physiologic effect of its secreted product (equine chorionic gonadotrophin) upon the recipient's ovaries, and induction of host immune responses. Immunologic memory has not been considered previously in this experimental system...
October 19, 2016: Biology of Reproduction
Jeroen Aerts, Annelies Laeremans, Laurens Minerva, Kurt Boonen, Budamgunta Harshavardhan, Rudi D'hooge, Dirk Valkenborg, Geert Baggerman, Lutgarde Arckens
The Morris water maze (MWM) spatial learning task has been demonstrated to involve a cognitive switch of action control to serve the transition from an early towards a late learning phase. However, the molecular mechanisms governing this switch are largely unknown. We employed MALDI MS imaging (MSI) to screen for changes in expression of small proteins in brain structures implicated in the different learning phases. We compared mice trained for 3days and 30days in the MWM, reflecting an early and a late learning phase in relation to the acquisition of a spatial learning task...
October 17, 2016: Biochimica et Biophysica Acta
Olena Bukalo, Philip R Lee, R Douglas Fields
Action-potential-induced LTD (AP-LTD) is a form of synaptic plasticity that reduces synaptic strength in CA1 hippocampal neurons firing antidromically during sharp-wave ripples. This firing occurs during slow-wave sleep and quiet moments of wakefulness, which are periods of offline replay of neural sequences learned during encoding sensory information. Here we report that rapid and persistent down-regulation of different mRNA transcripts of the BDNF gene accompanies AP-LTD, and that AP-LTD is abolished in mice with the BDNF gene knocked out in CA1 hippocampal neurons...
October 16, 2016: Neuroscience Letters
Erica M Barhorst-Cates, Kristina M Rand, Sarah H Creem-Regehr
Recent work with simulated reductions in visual acuity and contrast sensitivity has found decrements in survey spatial learning as well as increased attentional demands when navigating, compared to performance with normal vision. Given these findings, and previous work showing that peripheral field loss has been associated with impaired mobility and spatial memory for room-sized spaces, we investigated the role of peripheral vision during navigation using a large-scale spatial learning paradigm. First, we aimed to establish the magnitude of spatial memory errors at different levels of field restriction...
2016: PloS One
Marie McCann, Donna M Bayliss, Mike Anderson, Catherine Campbell, Noel French, Judy McMichael, Corinne Reid, Romola S Bucks
In two studies, the relationship between sleep and working memory performance was investigated in children born very preterm (i.e., gestation less than 32 weeks) and the possible mechanisms underlying this relationship. In Study 1, parent-reported measures of snoring, night-time sleep quality, and daytime sleepiness were collected on 89 children born very preterm aged 6 to 7 years. The children completed a verbal working memory task, as well as measures of processing speed and verbal storage capacity. Night-time sleep quality was found to be associated with verbal working memory performance over and above the variance associated with individual differences in processing speed and storage capacity, suggesting that poor sleep may have an impact on the executive component of working memory...
October 19, 2016: Child Neuropsychology: a Journal on Normal and Abnormal Development in Childhood and Adolescence
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"