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contextual memory

Lars Marstaller, Hana Burianová, David C Reutens
Safety learning describes the ability to learn that certain cues predict the absence of a dangerous or threatening event. Although incidental observations of activity within the default mode network (DMN) during the processing of safety cues have been reported previously, there is as yet no evidence demonstrating that the DMN plays a functional rather than a corollary role in safety learning. Using functional magnetic resonance imaging and a Pavlovian fear conditioning and extinction paradigm, we investigated the neural correlates of danger and safety learning...
October 21, 2016: Human Brain Mapping
Mutlu Mete, Unal Sakoglu, Jeffrey S Spence, Michael D Devous, Thomas S Harris, Bryon Adinoff
BACKGROUND: Neuroimaging studies have yielded significant advances in the understanding of neural processes relevant to the development and persistence of addiction. However, these advances have not explored extensively for diagnostic accuracy in human subjects. The aim of this study was to develop a statistical approach, using a machine learning framework, to correctly classify brain images of cocaine-dependent participants and healthy controls. In this study, a framework suitable for educing potential brain regions that differed between the two groups was developed and implemented...
October 6, 2016: BMC Bioinformatics
Douglas Senna Engelke, Renato Filev, Luiz E Mello, Jair Guilherme Santos-Junior
Addiction is a multifactorial disease that comprises physiological mechanisms of learning and memory. Addict subjects have intense plasticity in cortical and limbic circuits during intoxication, abstinence or even in drug seeking behavior. Locomotor sensitization is a classic animal model of drug addiction that mimics the changes that occur in the transition from drug use to drug addiction. Several studies have demonstrated the importance of contextual associative processes in this task. However, whether the mechanisms of sensitization are maintained and precise over the time remain an open question...
October 15, 2016: Behavioural Brain Research
Adam I Ramsaran, Hollie R Sanders, Mark E Stanton
Since the seminal report on novel object recognition in the rat (Ennaceur & Delacour, 1988), novelty recognition paradigms have become increasingly prevalent in learning and memory research. Novelty recognition tasks do not require extensive training or complex behaviors, and thus are especially suitable for studying the ontogeny of various forms of memory (e.g., object, spatial, and contextual memory). However, relatively little is known about the determinants of recognition memory during development. The present study extends our recent research on the development of recognition memory by further characterizing the ontogeny of contextual recognition (Ramsaran, Westbrook, & Stanton, 2016)...
November 2016: Developmental Psychobiology
Dae Young Yoo, Hyo Young Jung, Jong Whi Kim, Hee Sun Yim, Dae Won Kim, Hajin Nam, Jun Gyo Suh, Jung Hoon Choi, Moo-Ho Won, Yeo Sung Yoon, In Koo Hwang
Dynamin 1 is a known synaptic protein, which has is key in the presynaptic regulation of endocytosis. The present study investigated the association between age and the observed changes in Morris water maze performance, and immunoreactivity and protein levels of dynamin 1 in the mouse hippocampal formation. In addition, the effects of dynasore, an inhibitor of dynamin 1, on the hippocampal dependent memory were determined to elucidate the correlation between dynamin 1 and memory. In the training phase of the Morris water maze task, the mean escape latency of the aged group (24 months old) was significantly longer, compared with that of the adult group (4 months old), although the average swimming speed and the total distance traveled during the probe trial were similar in the two groups...
October 5, 2016: Molecular Medicine Reports
Isabel Vieira de Assis Lima, Alline Cristina de Campos, Paula Maria Quaglio Bellozi, Juliana Guimaraes Doria, Fabiola Mara Ribeiro, Marcio Flavio Dutra Moraes, Antonio Carlos Pinheiro de Oliveira
Temporal lobe epilepsy (TLE) is the most common form of epilepsy in adults. The pilocarpine (PILO) experimental model of TLE portrays behavioral and pathophysiological changes in rodents that are very similar to those found in humans with TLE. However, this model is associated with an unfortunate high mortality rate. Studies have shown that intrahippocampal injection of PILO, while having a much smaller mortality rate, induces status epilepticus (SE) that secondarily leads to TLE. To the best of our knowledge, the present study was the first to evaluate the cognitive and histological alterations 72h after intrahippocampal microinjection of PILO in C57BL/6 mice...
October 10, 2016: Epilepsy & Behavior: E&B
Brenna M Flannery, Donald A Bruun, Douglas J Rowland, Christopher N Banks, Adam T Austin, David L Kukis, Yonggang Li, Byron D Ford, Daniel J Tancredi, Jill L Silverman, Simon R Cherry, Pamela J Lein
BACKGROUND: Acute intoxication with organophosphorus (OP) cholinesterase inhibitors can trigger convulsions that progress to life-threatening status epilepticus. Survivors face long-term morbidity including mild-to-severe decline in memory. It is posited that neuroinflammation plays a key role in the pathogenesis of OP-induced neuropsychiatric deficits. Rigorous testing of this hypothesis requires preclinical models that recapitulate relevant phenotypic outcomes. Here, we describe a rat model of acute intoxication with the OP diisopropylfluorophosphate (DFP) that exhibits persistent neuroinflammation and cognitive impairment...
October 12, 2016: Journal of Neuroinflammation
Naoki Matsuo
No abstract text is available yet for this article.
2016: Nihon Yakurigaku Zasshi. Folia Pharmacologica Japonica
Jens G Klinzing, Björn Rasch, Jan Born, Susanne Diekelmann
Sleep is known to support the consolidation of newly encoded and initially labile memories. Once consolidated, remote memories can return to a labile state upon reactivation and need to become reconsolidated in order to persist. Here we asked whether sleep also benefits the reconsolidation of remote memories after their reactivation and how reconsolidation during sleep compares to sleep-dependent consolidation processes. In three groups, participants were trained on a visuo-spatial learning task in the presence of a contextual odor...
October 6, 2016: Neurobiology of Learning and Memory
Daniel Guerreiro Diniz, Marcus Augusto de Oliveira, Camila Mendes de Lima, César Augusto Raiol Fôro, Marcia Consentino Kronka Sosthenes, João Bento-Torres, Pedro Fernando da Costa Vasconcelos, Daniel Clive Anthony, Cristovam Wanderley Picanço Diniz
BACKGROUND: Few studies have explored the glial response to a standard environment and how the response may be associated with age-related cognitive decline in learning and memory. Here we investigated aging and environmental influences on hippocampal-dependent tasks and on the morphology of an unbiased selected population of astrocytes from the molecular layer of dentate gyrus, which is the main target of perforant pathway. RESULTS: Six and twenty-month-old female, albino Swiss mice were housed, from weaning, in a standard or enriched environment, including running wheels for exercise and tested for object recognition and contextual memories...
October 10, 2016: Behavioral and Brain Functions: BBF
Flurin Cathomas, Hannes Sigrist, Luca Schmid, Erich Seifritz, Martin Gassmann, Bernhard Bettler, Christopher R Pryce
Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the brain and is implicated in the pathophysiology of a number of neuropsychiatric disorders. The GABAB receptors are G-protein coupled receptors consisting of principle subunits and auxiliary potassium channel tetramerization domain (KCTD) subunits. The KCTD subunits 8, 12, 12b and 16 are cytosolic proteins that determine the kinetics of the GABAB receptor response. Previously, we demonstrated that Kctd12 null mutant mice (Kctd12(-/-)) exhibit increased auditory fear learning and that Kctd12(+/-) mice show altered circadian activity, as well as increased intrinsic excitability in hippocampal pyramidal neurons...
October 4, 2016: Behavioural Brain Research
Stephanie L Grella, Mélanie F Guigueno, David J White, David F Sherry, Diano F Marrone
In mammals, episodic memory and spatial cognition involve context-specific recruitment of unique ensembles in the hippocampal formation (HF). Despite their capacity for sophisticated spatial (e.g., for migration) and episodic-like (e.g., for food-caching) memory, the mechanisms underlying contextual representation in birds is not well understood. Here we demonstrate environment-specific Egr1 expression as male brown-headed cowbirds (Molothrus ater) navigate environments for food reward, showing that the avian HF, like its mammalian counterpart, recruits distinct neuronal ensembles to represent different contexts...
2016: PloS One
Marlene A Wilson, Jim R Fadel
Cholinergic activation regulates cognitive function, particularly long-term memory consolidation. This Review presents an overview of the anatomical, neurochemical, and pharmacological evidence supporting the cholinergic regulation of Pavlovian contextual and cue-conditioned fear learning and extinction. Basal forebrain cholinergic neurons provide inputs to neocortical regions and subcortical limbic structures such as the hippocampus and amygdala. Pharmacological manipulations of muscarinic and nicotinic receptors support the role of cholinergic processes in the amygdala, hippocampus, and prefrontal cortex in modulating the learning and extinction of contexts or cues associated with threat...
October 5, 2016: Journal of Neuroscience Research
Marna Eliana Sakalem, Thomas Seidenbecher, Mingyue Zhang, Roja Saffari, Mykola Kravchenko, Stephanie Wördemann, Kai Diederich, Jens C Schwamborn, Weiqi Zhang, Oliver Ambrée
It is well known that adult neurogenesis occurs in two distinct regions, the subgranular zone of the dentate gyrus and the subventricular zone along the walls of the lateral ventricles. Until now, the contribution of these newly born neurons to behavior and cognition is still uncertain. The current study tested the functional impacts of diminished hippocampal neurogenesis on emotional and cognitive functions in transgenic Gfap-tk mice. Our results showed that anxiety-related behavior evaluated both in the elevated plus maze as well as in the open field, social interaction in the sociability test, and spatial working memory in the spontaneous alternation test were not affected...
October 4, 2016: Hippocampus
Amy A Overman, Alison G Richard, Joseph D W Stephens
Self-generation of information during memory encoding has large positive effects on subsequent memory for items, but mixed effects on memory for contextual information associated with items. A processing account of generation effects on context memory (Mulligan in Journal of Experimental Psychology: Learning, Memory, and Cognition, 30(4), 838-855, 2004; Mulligan, Lozito, & Rosner in Journal of Experimental Psychology: Learning, Memory, and Cognition, 32(4), 836-846, 2006) proposes that these effects depend on whether the generation task causes any shift in processing of the type of context features for which memory is being tested...
September 30, 2016: Psychonomic Bulletin & Review
Danielle M Osborne, Kelsey E O'Leary, Dennis P Fitzgerald, Alvin J George, Michael M Vidal, Brian M Anderson, Ewan C McNay
AIMS/HYPOTHESIS: Recurrent hypoglycaemia is primarily caused by repeated over-administration of insulin to patients with diabetes. Although cognition is impaired during hypoglycaemia, restoration of euglycaemia after recurrent hypoglycaemia is associated with improved hippocampally mediated memory. Recurrent hypoglycaemia alters glucocorticoid secretion in response to hypoglycaemia; glucocorticoids are well established to regulate hippocampal processes, suggesting a possible mechanism for recurrent hypoglycaemia modulation of subsequent cognition...
September 29, 2016: Diabetologia
Soyoung Rhee, Gregory W Kirschen, Yan Gu, Shaoyu Ge
The primary cilium, a sensory organelle, regulates cell proliferation and neuronal development of dentate granule cells in the hippocampus. However, its role in the function of mature dentate granule cells remains unknown. Here we specifically depleted and disrupted ciliary proteins IFT20 and Kif3A (respectively) in mature dentate granule cells and investigated hippocampus-dependent contextual memory and long-term plasticity at mossy fiber synapses. We found that depletion of IFT20 in these cells significantly impaired context-dependent fear-related memory...
September 28, 2016: Scientific Reports
Rie Ishikawa, Hotaka Fukushima, Paul W Frankland, Satoshi Kida
Forgetting of recent fear memory is promoted by treatment with memantine (MEM), which increases hippocampal neurogenesis. The approaches for treatment of post-traumatic stress disorder (PTSD) using rodent models have focused on the extinction and reconsolidation of recent, but not remote, memories. Here we show that, following prolonged re-exposure to the conditioning context, enhancers of hippocampal neurogenesis, including MEM, promote forgetting of remote contextual fear memory. However, these interventions are ineffective following shorter re-exposures...
2016: ELife
Bianca Bucarelli, Christine Purdon
BACKGROUND AND OBJECTIVES: A growing body of research suggests that the repetition of an action degrades memory for that action, as well as confidence that is has been done correctly. This has important implications for understanding the compulsive repetition of actions characteristic of obsessive compulsive disorder (OCD). At this time, though, much of the research has been conducted on analogue or nonclinical OCD samples in comparison to healthy controls and often using virtual, as opposed to actual, threat stimuli...
December 2016: Journal of Behavior Therapy and Experimental Psychiatry
H A Cavus, Rachel M Msetfi
When there is no contingency between actions and outcomes, but outcomes occur frequently, people tend to judge that they have control over those outcomes, a phenomenon known as the outcome density (OD) effect. Recent studies show that the OD effect depends on the duration of the temporal interval between action-outcome conjunctions, with longer intervals inducing stronger effects. However, under some circumstances OD effect is reduced, for example when participants are mildly depressed. We reasoned that working memory (WM) plays an important role in learning of context; with reduced WM capacity to process contextual information during intertrial intervals (ITIs) during contingency learning might lead to reduced OD effects (limited capacity hypothesis)...
September 20, 2016: Acta Psychologica
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