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Nicola S. Clayton - One of the best experts on this subject based on the ideXlab platform.

  • Evidence of Episodic-Like Memory in cuttlefish
    Current Biology - CB, 2013
    Co-Authors: Christelle Jozet-alves, Marion Bertin, Nicola S. Clayton
    Abstract:

    The recollection of past experiences allows us to recall what happened during a particular event, and where and when it occurred [1]. Since the first study on Episodic-Like Memory in scrub-jays [2], there has been widespread acceptance of the idea that tests in animals should integrate the ‘what’, ‘where’ and ‘when’ components of a unique event that occurred in the past 3 and 4. This is referred to as Episodic-Like Memory rather than episodic Memory per se, in acknowledgement of the lack of evidence for, or against, the phenomenological aspects that accompany episodic recollection in humans. So far, evidence for Episodic-Like Memory has only been found in some birds and mammals. We show here that cuttlefish, cephalopod mollusks, keep track of what they have eaten, and where and how long ago they ate, in order to match their foraging behavior with the time of replenishing of different foods. Foraging in cuttlefish fulfils the criteria of ‘what’, ‘where’ and ‘when’ of unique events and thus provides behavioral evidence of Episodic-Like Memory in an invertebrate.

  • Ten years of research into avian models of Episodic-Like Memory and its implications for developmental and comparative cognition.
    Behavioural Brain Research, 2010
    Co-Authors: Lucie H. Salwiczek, Arii Watanabe, Nicola S. Clayton
    Abstract:

    Episodic Memory refers to the ability to remember specific personal events from the past. Ever since Tulving first made the distinction between episodic Memory and other forms of declarative Memory in 1972, most cognitive psychologists and neuroscientists have assumed that episodic recall is unique to humans. The seminal paper on Episodic-Like Memory in Western scrub-jays (Aphelocoma californica) by Clayton and Dickinson [4] has inspired a number of studies and in a wide range of species over the past 10 years. Here we shall first review the avian studies of what-where-when Memory, namely in the Western scrub-jays, magpies, black-capped chickadees and pigeons; we shall then present an alternative approach to studying Episodic-Like Memory also tested in pigeons. In the second and third section we want to draw attention to topics where we believe the bird model could prove highly valuable, namely studying development of episodic-Memory in pre-verbal children, and the evolution and ontogeny of brain areas subserving episodic(-like) Memory.

  • Evolution of the avian brain and intelligence.
    Current Biology, 2005
    Co-Authors: Nathan J. Emery, Nicola S. Clayton
    Abstract:

    Some birds are capable of cognitive feats which put most mammals to shame. In the rainforests of New Caledonia and Mare, New Caledonian crows use and construct a number of different tools which are used to gain access to large grubs found in the crevices of trees. These tools are crafted from raw materials (sticks and Pandanus leaves), and there is a suggestion that, like chimpanzees, crow tool use is a form of culture. In the laboratory, New Caledonian crows are equally impressive, demonstrating some understanding of ‘folk physics’ (the common sense view of how the world works). Perhaps the best demonstration of this is Betty the crow, who appeared to spontaneously bend a piece of wire into a hook to gain access to out-of-reach food.Other corvids are equally impressive, providing evidence of cognitive abilities thought to be uniquely human. Western scrub-jays, for example, are the first non-human animals to demonstrate Episodic-Like Memory — the ability to remember the ‘what, where and when’ of a specific past event. In these studies, jays cache different types of food which decay at different rates in specific locations. In order to recover food that is still fresh and edible, the jays had to remember ‘what’ type of food they cached, ‘where’ they cached and ‘when’ they cached it. Scrub-jays are also extremely wary of the presence of conspecifics during caching. If an observer is watching when scrub-jays cache, the storers come back later when alone and move their caches to new places that the observer does not know. Interestingly, storers only do this if they have been thieves themselves in the past. This suggests that experienced scrub-jays may attribute others with the intention of pilfering, and so implement strategies to reduce this possibility in the future. Scrub-jays also protect their caches by reducing the amount of information available to an observer at the time of caching, by hiding caches behind barriers, in the shade or as far from an observer as possible. All this suggests that western scrub-jays may demonstrate another supposedly unique form of human cognition: theory of mind. Parrots, such as Alex the African grey, have also demonstrated intellectual abilities which rival primates, such as understanding whether objects are the same or different, their number (including zero), their colour and shape.Our new appreciation of the complexity of the avian brain is closely tied with a new appreciation of the complexity of the avian mind, particularly with respect to corvids and parrots. It is now the job of behavioural biologists, comparative psychologists and neuroscientists to determine how one translates into the other.

  • Retrospective Cognition by Food-Caching Western Scrub-Jays.
    Learning and Motivation, 2005
    Co-Authors: Selvino R. De Kort, Anthony Dickinson, Nicola S. Clayton
    Abstract:

    Abstract Episodic-Like Memory, the retrospective component of cognitive time travel in animals, needs to fulfil three criteria to meet the behavioral properties of episodic Memory as defined for humans. Here, we review results obtained with the cache-recovery paradigm with western scrub-jays and conclude that they fulfil these three criteria. The jays remember the what-when-where components of a caching episode (content), these components are integrated (structure), and can be updated and generalized over situations (flexibility). The interpretation of the temporal aspect of the jays’ episodic Memory remains contentious however. For the Memory to be Episodic-Like, the when component needs to result from time being encoded explicitly in Memory as opposed to being a by-product of a decaying Memory trace. We present new data in favor of explicit encoding of temporal information in the Memory of scrub-jays. Finally, we discuss Episodic-Like Memory in scrub-jays in relation to results obtained with other species.

  • Can animals recall the past and plan for the future
    Nature Reviews Neuroscience, 2003
    Co-Authors: Nicola S. Clayton, Timothy J. Bussey, Anthony Dickinson
    Abstract:

    According to the 'mental time travel hypothesis' animals, unlike humans, cannot mentally travel backwards in time to recollect specific past events (episodic Memory) or forwards to anticipate future needs (future planning). Until recently, there was little evidence in animals for either ability. Experiments on Memory in food-caching birds, however, question this assumption by showing that western scrub-jays form integrated, flexible, trial-unique memories of what they hid, where and when. Moreover, these birds can adjust their caching behaviour in anticipation of future needs. We suggest that some animals have elements of both Episodic-Like Memory and future planning.

Michel Boulouard - One of the best experts on this subject based on the ideXlab platform.

  • Modulation of 5-HT_7 receptor: effect on object recognition performances in mice
    Psychopharmacology, 2014
    Co-Authors: Thomas Freret, Eleni Paizanis, François Dauphin, Gregory Beaudet, Andreia Gusmao-montaigne, Gerald Nee, Valentine Bouet, Michel Boulouard
    Abstract:

    Objective Recent data suggest that 5-HT_7 receptors (5-HT_7R) are involved in Memory processes and, particularly, those related to novelty-induced arousal, even though this remains so far speculative and controversial. In order to assess the role of 5-HT_7R in Episodic-Like Memory, mice were administered 5-carboxamidotryptamine (5-CT, a 5-HT_1A/1B/1D/7R agonist) and/or SB-269970 (a selective 5-HT_7R antagonist) immediately after the acquisition session of the novel object recognition test. Materials and methods The object recognition test was performed in order to assess the effects of modulation of 5-HT_7R during consolidation phase on Episodic-Like Memory performances in mice. A protocol including 3 days of familiarisation to the apparatus has been realised in order to decrease the effect of novelty-induced arousal. Results With a 2-h delay, SB-269970 (3 and 10 mg/kg, administered subcutaneously) impaired the discrimination of the novel object. With a 4-h delay, while control mice were not able to discriminate the novel object, mice treated with 5-CT (1 mg/kg) showed a significant discrimination. This promnesic effect with a long delay is effectively mediated by 5-HT_7R activation since it was blocked by SB-269970 (10 mg/kg), but not by WAY-100135 (10 mg/kg) or by GR-127935 (10 mg/kg). Conclusion These data suggest that 5-HT_7R tonically modulates cognitive processes involved in consolidation performances in object recognition. Therefore, 5-HT_7R could be a promising target to treat Memory dysfunctions (especially episodically related deficits) related to normal or pathological ageing.

  • 5-HT6 receptor blockade differentially affects scopolamine-induced deficits of working Memory, recognition Memory and aversive learning in mice.
    Psychopharmacology, 2012
    Co-Authors: Virginie Da Silva Costa-aze, Anne Quiedeville, Michel Boulouard, François Dauphin
    Abstract:

    RATIONALE: Blockade of 5-HT6 receptors (5-HT6R) is known to improve cognitive performances in the rodent. This improvement has been hypothesized to be the result, at least in part, of a modulation of the cholinergic neurotransmission. OBJECTIVE: We assessed the effects of 5-HT6R blockade on selected types of Memory relevant to functional deficits of ageing and neurodegenerative diseases, in mice that present a scopolamine-induced cholinergic disruption of Memory. METHOD: Following the selection of an adequate dose of scopolamine to induce cognitive deficits, we have studied the effects of the selective 5-HT6R antagonist SB-271046, alone or in combination with scopolamine, on working Memory (spontaneous alternation task in the T-maze), recognition Memory (place recognition) and aversive learning (passive avoidance). RESULTS: SB-271046 alone failed to affect working Memory, recognition Memory and aversive learning performances. In contrast, SB-271046 was able to reverse the scopolamine-induced deficits in working Memory (only at 30 mg kg⁻¹) and those of acquisition and retrieval of aversive learning (dose-dependent effect); scopolamine-induced deficits in Episodic-Like Memory (acquisition and retrieval) were partially counteracted by 5-HT6R blockade. CONCLUSION: The modulation between 5-HT6R and the cholinergic system appears to be predominant for working Memory and aversive learning, but not for other types of Memory (i.e. Episodic-Like Memory). Interactions between 5-HT6R and alternative neurotransmission systems (i.e. glutamatergic system) should be further studied. The respective involvement of these interactions in the Memory disorders related to ageing and neurodegenerative diseases is of pivotal importance regarding the possible use of 5-HT6R antagonists in the treatment of Memory disorders in humans.

  • Synergistic effect of acetylcholinesterase inhibition (donepezil) and 5-HT(4) receptor activation (RS67333) on object recognition in mice.
    Behavioural Brain Research, 2012
    Co-Authors: Thomas Freret, Anne Quiedeville, Gerald Nee, Valentine Bouet, Patrick Dallemagne, Christophe Rochais, Michel Boulouard
    Abstract:

    Facing inefficiency of current treatments to cure Alzheimer disease (AD), a pharmacological approach is now emerging on the assumption that a single compound may be able to hit multiple targets, namely Multi-Target-Directed Ligands (MTDLs). Displaying numerous advantages, several MTDL for AD have been recently described but none associating an inhibition of AChE and an activation of 5-HT(4)R. The aim of this study was to validate the concept of a synergistic action of these two targets on Episodic-Like Memory performances in mice. Among potent molecules, RS67333, a reference 5-HT(4)R agonist and donepezil (DNPZ), a reference acetylcholinesterase inhibitor, have been particularly chosen because of their close chemical structure. Administered separately, RS67333 (0.3 and 1mg/kg) and DNPZ (1mg/kg) improved recognition performances compared to saline treated animals but not with lower doses. Co-administration of subactive doses of RS67333 (0.1mg/kg) and DNPZ (0.3mg/kg) improved Memory, moreover, this improvement is prevented if a 5-HT(4)R antagonist (GR125487, 10mg/kg) is also administered. Activation of 5-HT(4)R combined with inhibition of AChE with subactive doses of RS67333 and of DNPZ has synergistic effects on Memory performances in mice. These molecules having close chemical structures, the synergistic effect of their combination affords new hope to chemist for the synthesis of MTDL.

  • Environmental enrichment enhances Episodic-Like Memory in association with a modified neuronal activation profile in adult mice.
    PLoS ONE, 2012
    Co-Authors: Marianne Leger, Thomas Freret, Anne Quiedeville, Eleni Paizanis, Sharuja Natkunarajah, Michel Boulouard, Pascale Schumann-bard
    Abstract:

    Although environmental enrichment is well known to improve learning and Memory in rodents, the underlying neuronal networks' plasticity remains poorly described. Modifications of the brain activation pattern by enriched condition (EC), especially in the frontal cortex and the baso-lateral amygdala, have been reported during an aversive Memory task in rodents. The aims of our study were to examine 1) whether EC modulates Episodic-Like Memory in an object recognition task and 2) whether EC modulates the task-induced neuronal networks. To this end, adult male mice were housed either in standard condition (SC) or in EC for three weeks before behavioral experiments (n = 12/group). Memory performances were examined in an object recognition task performed in a Y-maze with a 2-hour or 24-hour delay between presentation and test (inter-session intervals, ISI). To characterize the mechanisms underlying the promnesiant effect of EC, the brain activation profile was assessed after either the presentation or the test sessions using immunohistochemical techniques with c-Fos as a neuronal activation marker. EC did not modulate Memory performances after a 2 h-ISI, but extended object recognition Memory to a 24 h-ISI. In contrast, SC mice did not discriminate the novel object at this ISI. Compared to SC mice, no activation related to the presentation session was found in selected brain regions of EC mice (in particular, no effect was found in the hippocampus and the perirhinal cortex and a reduced activation was found in the baso-lateral amygdala). On the other hand, an activation of the hippocampus and the infralimbic cortex was observed after the test session for EC, but not SC mice. These results suggest that the persistence of object recognition Memory in EC could be related to a reorganization of neuronal networks occurring as early as the Memory encoding.

  • A biphasic and brain-region selective down-regulation of cyclic adenosine monophosphate concentrations supports object recognition in the rat.
    PLoS ONE, 2012
    Co-Authors: Maïte Hotte, Thomas Freret, Michel Boulouard, François Dauphin, Guenaëlle Levallet
    Abstract:

    BACKGROUND: We aimed to further understand the relationship between cAMP concentration and mnesic performance. METHODS AND FINDINGS: Rats were injected with milrinone (PDE3 inhibitor, 0.3 mg/kg, i.p.), rolipram (PDE4 inhibitor, 0.3 mg/kg, i.p.) and/or the selective 5-HT4R agonist RS 67333 (1 mg/kg, i.p.) before testing in the object recognition paradigm. Cyclic AMP concentrations were measured in brain structures linked to Episodic-Like Memory (i.e. hippocampus, prefrontal and perirhinal cortices) before or after either the sample or the testing phase. Except in the hippocampus of rolipram treated-rats, all treatment increased cAMP levels in each brain sub-region studied before the sample phase. After the sample phase, cAMP levels were significantly increased in hippocampus (1.8 fold), prefrontal (1.3 fold) and perirhinal (1.3 fold) cortices from controls rat while decreased in prefrontal cortex (∼0.83 to 0.62 fold) from drug-treated rats (except for milrinone+RS 67333 treatment). After the testing phase, cAMP concentrations were still increased in both the hippocampus (2.76 fold) and the perirhinal cortex (2.1 fold) from controls animals. Minor increase were reported in hippocampus and perirhinal cortex from both rolipram (respectively, 1.44 fold and 1.70 fold) and milrinone (respectively 1.46 fold and 1.56 fold)-treated rat. Following the paradigm, cAMP levels were significantly lower in the hippocampus, prefrontal and perirhinal cortices from drug-treated rat when compared to controls animals, however, only drug-treated rats spent longer time exploring the novel object during the testing phase (inter-phase interval of 4 h). CONCLUSIONS: Our results strongly suggest that a "pre-sample" early increase in cAMP levels followed by a specific lowering of cAMP concentrations in each brain sub-region linked to the object recognition paradigm support learning efficacy after a middle-term delay.

Maria A. De Souza Silva - One of the best experts on this subject based on the ideXlab platform.

  • the hippocampal cortical networks subserving episodic Memory and its component Memory systems for object place and temporal order
    2018
    Co-Authors: Owen Y. Chao, Joseph P. Huston, Maria A. De Souza Silva
    Abstract:

    Abstract We here review the status of research on the neurobiological mechanism of episodic Memory as defined by an integrated Memory of the experience of an object or event, in a particular place and time. A particular focus is the development of an animal model of Episodic-Like Memory which combines the novel object preference test (what), the novel location preference test (where) and test for temporal order (when) ( Kart-Teke et al., 2006 ). Behavioural, electrophysiological, imaging and lesion studies have shown that the prefrontal cortex (PFC), hippocampus and interconnected neural areas, such as the lateral entorhinal cortex, are implicated in the processing of memories for what, where or when. We ask whether the integration of memories for “what”, “where” and “when” into Episodic-Like Memory and its component Memory systems for event, place and time of occurrence are dependent on these circuits. The prefrontal cortex processes what and where information and assists for the associated memories. The lateral entorhinal cortex is critical for the processing of object-related associative information but not object identity itself. The hippocampus is essentially involved in what, where and when memories. Thus, we focus on the roles of the PFC, hippocampus and lateral entorhinal cortex in the processing of Episodic-Like Memory. Disconnection studies show that interactions between the PFC and hippocampus (CA1/CA3) and the interplay of the PFC and lateral entorhinal cortex are critical substrates for the establishment of an integrated Episodic-Like Memory. We delineate a detailed neuronal network of Episodic-Like Memory which includes these structures in the integration of memories for “what”, “where” and “when” as prototype of episodic Memory.

  • interaction between the medial prefrontal cortex and hippocampal ca1 area is essential for episodic like Memory in rats
    Neurobiology of Learning and Memory, 2017
    Co-Authors: Owen Y. Chao, Susanne Nikolaus, Joseph P. Huston, Marcus Lira Brandao, Maria A. De Souza Silva
    Abstract:

    The interplay between medial prefrontal cortex (mPFC) and hippocampus, particularly the hippocampal CA3 area, is critical for episodic Memory. To what extent the mPFC also interacts with the hippocampus CA1 subregion still requires elucidation. To investigate this issue, male rats received unilateral N-methyl-D-aspartate lesions of the mPFC together with unilateral lesions of the hippocampal CA1 area, either in the same (control) or in the opposite hemispheres (disconnection). They underwent an Episodic-Like Memory test, combining what-where-when information, and separate tests for novel object preference (what), object place preference (where) and temporal order Memory (when). Compared to controls, the disconnected mPFC-CA1 rats exhibited disrupted Episodic-Like Memory with an impaired integration of the what-where-when elements. Both groups showed intact memories for what and when, while only the control group showed intact Memory for where. These findings suggest that the functional interaction of the mPFC-CA1 circuit is crucial for the processing of episodic Memory and, in particular, for the integration of the spatial Memory component.

  • evidence for a specific integrative mechanism for episodic Memory mediated by ampa kainate receptors in a circuit involving medial prefrontal cortex and hippocampal ca3 region
    Cerebral Cortex, 2016
    Co-Authors: Maria A. De Souza Silva, Joseph P. Huston, Anli Wang, David Petri, Owen Y. Chao
    Abstract:

    We asked whether Episodic-Like Memory requires neural mechanisms independent of those that mediate its component memories for "what," "when," and "where," and if neuronal connectivity between the medial prefrontal cortex (mPFC) and the hippocampus (HPC) CA3 subregion is essential for Episodic-Like Memory. Unilateral lesion of the mPFC was combined with unilateral lesion of the CA3 in the ipsi- or contralateral hemispheres in rats. Episodic-Like Memory was tested using a task, which assesses the integration of memories for "what, where, and when" concomitantly. Tests for novel object recognition (what), object place (where), and temporal order Memory (when) were also applied. Bilateral disconnection of the mPFC-CA3 circuit by N-methyl-d-aspartate (NMDA) lesions disrupted Episodic-Like Memory, but left the component memories for object, place, and temporal order, per se, intact. Furthermore, unilateral NMDA lesion of the CA3 plus injection of (6-cyano-7-nitroquinoxaline-2,3-dione) (CNQX) (AMPA/kainate receptor antagonist), but not AP-5 (NMDA receptor antagonist), into the contralateral mPFC also disrupted Episodic-Like Memory, indicating the mPFC AMPA/kainate receptors as critical for this circuit. These results argue for a selective neural system that specifically subserves episodic Memory, as it is not critically involved in the control of its component memories for object, place, and time.

  • the medial prefrontal cortex lateral entorhinal cortex circuit is essential for episodic like Memory and associative object recognition
    Hippocampus, 2016
    Co-Authors: Owen Y. Chao, Joseph P. Huston, Anli Wang, Maria A. De Souza Silva
    Abstract:

    The prefrontal cortex directly projects to the lateral entorhinal cortex (LEC), an important substrate for engaging item-associated information and relaying the information to the hippocampus. Here we ask to what extent the communication between the prefrontal cortex and LEC is critically involved in the processing of Episodic-Like Memory. We applied a disconnection procedure to test whether the interaction between the medial prefrontal cortex (mPFC) and LEC is essential for the expression of recognition Memory. It was found that male rats that received unilateral NMDA lesions of the mPFC and LEC in the same hemisphere, exhibited intact Episodic-Like (what-where-when) and object-recognition memories. When these lesions were placed in the opposite hemispheres (disconnection), Episodic-Like and associative memories for object identity, location and context were impaired. However, the disconnection did not impair the components of episodic Memory, namely Memory for novel object (what), object place (where) and temporal order (when), per se. Thus, the present findings suggest that the mPFC and LEC are a critical part of a neural circuit that underlies Episodic-Like and associative object-recognition Memory.

  • The neurokinin-3 receptor agonist senktide facilitates the integration of memories for object, place and temporal order into episodic Memory.
    Neurobiology of Learning and Memory, 2014
    Co-Authors: Owen Y. Chao, Susanne Nikolaus, Joseph P. Huston, Maria A. De Souza Silva
    Abstract:

    Abstract Senktide, a potent neurokinin-3 receptor (NK3-R) agonist, has been shown to have promnestic effects in adult and aged rodents and to facilitate Episodic-Like Memory (ELM) in mice when administrated before the learning trial. In the present study we assessed the effects of senktide on Memory consolidation by administering it post-trial (after the learning trial) in adult rats. We applied an ELM test, based on the integrated Memory for object, place and temporal order, which we developed ( Kart-Teke, de Souza Silva, Huston, & Dere, 2006 ). This test involves two learning trials and one test trial. We examined intervals of 1 h and 23 h between the learning and test trials (experiment 1) in untreated animals and found that they exhibited intact ELM after a delay of 1 h, but not 23 h. In another test for ELM performed 7 days later, vehicle or senktide (0.2 mg/kg, s.c.) was applied immediately after the second learning trial and the test was conducted 23 h later (experiment 2). Senktide treatment recovered components of ELM (Memory for place and object) compared with vehicle-treated animals. After one more week, vehicle or senktide (0.2 mg/kg, s.c.) was applied post-trial and the test conducted 6 h later (experiment 3). The senktide-treated group exhibited intact ELM, unlike the vehicle-treated group. Finally, animals received post-trial treatment with either vehicle or SR142801, a selective NK3-R antagonist (6 mg/kg, i.p.), 1 min before senktide injection (0.2 mg/kg, s.c.) in the ELM paradigm and were tested 6 h later (experiment 4). The vehicle + senktide group showed intact ELM, while the SR142801 + senktide group did not. The results indicate that senktide facilitated the consolidation or the expression of ELM and that the senktide effect was NK3-R dependent.

Thomas Freret - One of the best experts on this subject based on the ideXlab platform.

  • Time decay of object, place and temporal order Memory in a paradigm assessing simultaneously Episodic-Like Memory components in mice
    Behavioural Brain Research, 2015
    Co-Authors: Hassina Belblidia, Abdelmalek Abdelouadoud, Christelle Jozet-alves, Hélène Dumas, Thomas Freret, Marianne Leger, Pascale Schumann-bard
    Abstract:

    A common trait of numerous Memory disorders is the impairment of episodic Memory. Episodic Memory is a delay-dependant Memory, especially associating three components, the "what", "where" and "when" of a unique event. To investigate underlying mechanisms of such Memory, several tests, mainly based on object exploration behaviour, have been set up in rodents. Recently, a three-trial object recognition task has been proposed to evaluate simultaneously the different components of Episodic-Like Memory in rodents. However, to date, the time course of each Memory component in this paradigm is not known. We characterised here the time course of Memory decay in adult mice during the three-trial object recognition task, with inter-trial interval (ITI) ranging from 1 h to 4 h. We found that, with 1 hand 2 h, but not 4h ITI, mice spent more time to explore the displaced "old object" relative to the displaced "recent object", reflecting Memory for "what and when". Concomitantly, animals exhibited more exploration time for the displaced "old object" relative to the stationary "old object", reflecting Memory for "what and where". These results provide strong evidence that mice establish an integrated Memory for unique experience consisting of the "what", "where" and "when" that can persist until 2 h ITI. (C) 2015 Elsevier B.V. All rights reserved.

  • Time decay of object, place and temporal order Memory in a paradigm assessing simultaneously Episodic-Like Memory components in mice.
    Behavioural Brain Research, 2015
    Co-Authors: Hassina Belblidia, Abdelmalek Abdelouadoud, Christelle Jozet-alves, Hélène Dumas, Thomas Freret, Marianne Leger, Pascale Schumann-bard
    Abstract:

    Abstract A common trait of numerous Memory disorders is the impairment of episodic Memory. Episodic Memory is a delay-dependant Memory, especially associating three components, the “what”, “where” and “when” of a unique event. To investigate underlying mechanisms of such Memory, several tests, mainly based on object exploration behaviour, have been set up in rodents. Recently, a three-trial object recognition task has been proposed to evaluate simultaneously the different components of Episodic-Like Memory in rodents. However, to date, the time course of each Memory component in this paradigm is not known. We characterised here the time course of Memory decay in adult mice during the three-trial object recognition task, with inter-trial interval (ITI) ranging from 1 h to 4 h. We found that, with 1 h and 2 h, but not 4 h ITI, mice spent more time to explore the displaced “old object” relative to the displaced “recent object”, reflecting Memory for “what and when”. Concomitantly, animals exhibited more exploration time for the displaced “old object” relative to the stationary “old object”, reflecting Memory for “what and where”. These results provide strong evidence that mice establish an integrated Memory for unique experience consisting of the “what”, “where” and “when” that can persist until 2 h ITI.

  • Modulation of 5-HT_7 receptor: effect on object recognition performances in mice
    Psychopharmacology, 2014
    Co-Authors: Thomas Freret, Eleni Paizanis, François Dauphin, Gregory Beaudet, Andreia Gusmao-montaigne, Gerald Nee, Valentine Bouet, Michel Boulouard
    Abstract:

    Objective Recent data suggest that 5-HT_7 receptors (5-HT_7R) are involved in Memory processes and, particularly, those related to novelty-induced arousal, even though this remains so far speculative and controversial. In order to assess the role of 5-HT_7R in Episodic-Like Memory, mice were administered 5-carboxamidotryptamine (5-CT, a 5-HT_1A/1B/1D/7R agonist) and/or SB-269970 (a selective 5-HT_7R antagonist) immediately after the acquisition session of the novel object recognition test. Materials and methods The object recognition test was performed in order to assess the effects of modulation of 5-HT_7R during consolidation phase on Episodic-Like Memory performances in mice. A protocol including 3 days of familiarisation to the apparatus has been realised in order to decrease the effect of novelty-induced arousal. Results With a 2-h delay, SB-269970 (3 and 10 mg/kg, administered subcutaneously) impaired the discrimination of the novel object. With a 4-h delay, while control mice were not able to discriminate the novel object, mice treated with 5-CT (1 mg/kg) showed a significant discrimination. This promnesic effect with a long delay is effectively mediated by 5-HT_7R activation since it was blocked by SB-269970 (10 mg/kg), but not by WAY-100135 (10 mg/kg) or by GR-127935 (10 mg/kg). Conclusion These data suggest that 5-HT_7R tonically modulates cognitive processes involved in consolidation performances in object recognition. Therefore, 5-HT_7R could be a promising target to treat Memory dysfunctions (especially episodically related deficits) related to normal or pathological ageing.

  • Synergistic effect of acetylcholinesterase inhibition (donepezil) and 5-HT(4) receptor activation (RS67333) on object recognition in mice.
    Behavioural Brain Research, 2012
    Co-Authors: Thomas Freret, Anne Quiedeville, Gerald Nee, Valentine Bouet, Patrick Dallemagne, Christophe Rochais, Michel Boulouard
    Abstract:

    Facing inefficiency of current treatments to cure Alzheimer disease (AD), a pharmacological approach is now emerging on the assumption that a single compound may be able to hit multiple targets, namely Multi-Target-Directed Ligands (MTDLs). Displaying numerous advantages, several MTDL for AD have been recently described but none associating an inhibition of AChE and an activation of 5-HT(4)R. The aim of this study was to validate the concept of a synergistic action of these two targets on Episodic-Like Memory performances in mice. Among potent molecules, RS67333, a reference 5-HT(4)R agonist and donepezil (DNPZ), a reference acetylcholinesterase inhibitor, have been particularly chosen because of their close chemical structure. Administered separately, RS67333 (0.3 and 1mg/kg) and DNPZ (1mg/kg) improved recognition performances compared to saline treated animals but not with lower doses. Co-administration of subactive doses of RS67333 (0.1mg/kg) and DNPZ (0.3mg/kg) improved Memory, moreover, this improvement is prevented if a 5-HT(4)R antagonist (GR125487, 10mg/kg) is also administered. Activation of 5-HT(4)R combined with inhibition of AChE with subactive doses of RS67333 and of DNPZ has synergistic effects on Memory performances in mice. These molecules having close chemical structures, the synergistic effect of their combination affords new hope to chemist for the synthesis of MTDL.

  • Environmental enrichment enhances Episodic-Like Memory in association with a modified neuronal activation profile in adult mice.
    PLoS ONE, 2012
    Co-Authors: Marianne Leger, Thomas Freret, Anne Quiedeville, Eleni Paizanis, Sharuja Natkunarajah, Michel Boulouard, Pascale Schumann-bard
    Abstract:

    Although environmental enrichment is well known to improve learning and Memory in rodents, the underlying neuronal networks' plasticity remains poorly described. Modifications of the brain activation pattern by enriched condition (EC), especially in the frontal cortex and the baso-lateral amygdala, have been reported during an aversive Memory task in rodents. The aims of our study were to examine 1) whether EC modulates Episodic-Like Memory in an object recognition task and 2) whether EC modulates the task-induced neuronal networks. To this end, adult male mice were housed either in standard condition (SC) or in EC for three weeks before behavioral experiments (n = 12/group). Memory performances were examined in an object recognition task performed in a Y-maze with a 2-hour or 24-hour delay between presentation and test (inter-session intervals, ISI). To characterize the mechanisms underlying the promnesiant effect of EC, the brain activation profile was assessed after either the presentation or the test sessions using immunohistochemical techniques with c-Fos as a neuronal activation marker. EC did not modulate Memory performances after a 2 h-ISI, but extended object recognition Memory to a 24 h-ISI. In contrast, SC mice did not discriminate the novel object at this ISI. Compared to SC mice, no activation related to the presentation session was found in selected brain regions of EC mice (in particular, no effect was found in the hippocampus and the perirhinal cortex and a reduced activation was found in the baso-lateral amygdala). On the other hand, an activation of the hippocampus and the infralimbic cortex was observed after the test session for EC, but not SC mice. These results suggest that the persistence of object recognition Memory in EC could be related to a reorganization of neuronal networks occurring as early as the Memory encoding.

Owen Y. Chao - One of the best experts on this subject based on the ideXlab platform.

  • the hippocampal cortical networks subserving episodic Memory and its component Memory systems for object place and temporal order
    2018
    Co-Authors: Owen Y. Chao, Joseph P. Huston, Maria A. De Souza Silva
    Abstract:

    Abstract We here review the status of research on the neurobiological mechanism of episodic Memory as defined by an integrated Memory of the experience of an object or event, in a particular place and time. A particular focus is the development of an animal model of Episodic-Like Memory which combines the novel object preference test (what), the novel location preference test (where) and test for temporal order (when) ( Kart-Teke et al., 2006 ). Behavioural, electrophysiological, imaging and lesion studies have shown that the prefrontal cortex (PFC), hippocampus and interconnected neural areas, such as the lateral entorhinal cortex, are implicated in the processing of memories for what, where or when. We ask whether the integration of memories for “what”, “where” and “when” into Episodic-Like Memory and its component Memory systems for event, place and time of occurrence are dependent on these circuits. The prefrontal cortex processes what and where information and assists for the associated memories. The lateral entorhinal cortex is critical for the processing of object-related associative information but not object identity itself. The hippocampus is essentially involved in what, where and when memories. Thus, we focus on the roles of the PFC, hippocampus and lateral entorhinal cortex in the processing of Episodic-Like Memory. Disconnection studies show that interactions between the PFC and hippocampus (CA1/CA3) and the interplay of the PFC and lateral entorhinal cortex are critical substrates for the establishment of an integrated Episodic-Like Memory. We delineate a detailed neuronal network of Episodic-Like Memory which includes these structures in the integration of memories for “what”, “where” and “when” as prototype of episodic Memory.

  • interaction between the medial prefrontal cortex and hippocampal ca1 area is essential for episodic like Memory in rats
    Neurobiology of Learning and Memory, 2017
    Co-Authors: Owen Y. Chao, Susanne Nikolaus, Joseph P. Huston, Marcus Lira Brandao, Maria A. De Souza Silva
    Abstract:

    The interplay between medial prefrontal cortex (mPFC) and hippocampus, particularly the hippocampal CA3 area, is critical for episodic Memory. To what extent the mPFC also interacts with the hippocampus CA1 subregion still requires elucidation. To investigate this issue, male rats received unilateral N-methyl-D-aspartate lesions of the mPFC together with unilateral lesions of the hippocampal CA1 area, either in the same (control) or in the opposite hemispheres (disconnection). They underwent an Episodic-Like Memory test, combining what-where-when information, and separate tests for novel object preference (what), object place preference (where) and temporal order Memory (when). Compared to controls, the disconnected mPFC-CA1 rats exhibited disrupted Episodic-Like Memory with an impaired integration of the what-where-when elements. Both groups showed intact memories for what and when, while only the control group showed intact Memory for where. These findings suggest that the functional interaction of the mPFC-CA1 circuit is crucial for the processing of episodic Memory and, in particular, for the integration of the spatial Memory component.

  • evidence for a specific integrative mechanism for episodic Memory mediated by ampa kainate receptors in a circuit involving medial prefrontal cortex and hippocampal ca3 region
    Cerebral Cortex, 2016
    Co-Authors: Maria A. De Souza Silva, Joseph P. Huston, Anli Wang, David Petri, Owen Y. Chao
    Abstract:

    We asked whether Episodic-Like Memory requires neural mechanisms independent of those that mediate its component memories for "what," "when," and "where," and if neuronal connectivity between the medial prefrontal cortex (mPFC) and the hippocampus (HPC) CA3 subregion is essential for Episodic-Like Memory. Unilateral lesion of the mPFC was combined with unilateral lesion of the CA3 in the ipsi- or contralateral hemispheres in rats. Episodic-Like Memory was tested using a task, which assesses the integration of memories for "what, where, and when" concomitantly. Tests for novel object recognition (what), object place (where), and temporal order Memory (when) were also applied. Bilateral disconnection of the mPFC-CA3 circuit by N-methyl-d-aspartate (NMDA) lesions disrupted Episodic-Like Memory, but left the component memories for object, place, and temporal order, per se, intact. Furthermore, unilateral NMDA lesion of the CA3 plus injection of (6-cyano-7-nitroquinoxaline-2,3-dione) (CNQX) (AMPA/kainate receptor antagonist), but not AP-5 (NMDA receptor antagonist), into the contralateral mPFC also disrupted Episodic-Like Memory, indicating the mPFC AMPA/kainate receptors as critical for this circuit. These results argue for a selective neural system that specifically subserves episodic Memory, as it is not critically involved in the control of its component memories for object, place, and time.

  • the medial prefrontal cortex lateral entorhinal cortex circuit is essential for episodic like Memory and associative object recognition
    Hippocampus, 2016
    Co-Authors: Owen Y. Chao, Joseph P. Huston, Anli Wang, Maria A. De Souza Silva
    Abstract:

    The prefrontal cortex directly projects to the lateral entorhinal cortex (LEC), an important substrate for engaging item-associated information and relaying the information to the hippocampus. Here we ask to what extent the communication between the prefrontal cortex and LEC is critically involved in the processing of Episodic-Like Memory. We applied a disconnection procedure to test whether the interaction between the medial prefrontal cortex (mPFC) and LEC is essential for the expression of recognition Memory. It was found that male rats that received unilateral NMDA lesions of the mPFC and LEC in the same hemisphere, exhibited intact Episodic-Like (what-where-when) and object-recognition memories. When these lesions were placed in the opposite hemispheres (disconnection), Episodic-Like and associative memories for object identity, location and context were impaired. However, the disconnection did not impair the components of episodic Memory, namely Memory for novel object (what), object place (where) and temporal order (when), per se. Thus, the present findings suggest that the mPFC and LEC are a critical part of a neural circuit that underlies Episodic-Like and associative object-recognition Memory.

  • The neurokinin-3 receptor agonist senktide facilitates the integration of memories for object, place and temporal order into episodic Memory.
    Neurobiology of Learning and Memory, 2014
    Co-Authors: Owen Y. Chao, Susanne Nikolaus, Joseph P. Huston, Maria A. De Souza Silva
    Abstract:

    Abstract Senktide, a potent neurokinin-3 receptor (NK3-R) agonist, has been shown to have promnestic effects in adult and aged rodents and to facilitate Episodic-Like Memory (ELM) in mice when administrated before the learning trial. In the present study we assessed the effects of senktide on Memory consolidation by administering it post-trial (after the learning trial) in adult rats. We applied an ELM test, based on the integrated Memory for object, place and temporal order, which we developed ( Kart-Teke, de Souza Silva, Huston, & Dere, 2006 ). This test involves two learning trials and one test trial. We examined intervals of 1 h and 23 h between the learning and test trials (experiment 1) in untreated animals and found that they exhibited intact ELM after a delay of 1 h, but not 23 h. In another test for ELM performed 7 days later, vehicle or senktide (0.2 mg/kg, s.c.) was applied immediately after the second learning trial and the test was conducted 23 h later (experiment 2). Senktide treatment recovered components of ELM (Memory for place and object) compared with vehicle-treated animals. After one more week, vehicle or senktide (0.2 mg/kg, s.c.) was applied post-trial and the test conducted 6 h later (experiment 3). The senktide-treated group exhibited intact ELM, unlike the vehicle-treated group. Finally, animals received post-trial treatment with either vehicle or SR142801, a selective NK3-R antagonist (6 mg/kg, i.p.), 1 min before senktide injection (0.2 mg/kg, s.c.) in the ELM paradigm and were tested 6 h later (experiment 4). The vehicle + senktide group showed intact ELM, while the SR142801 + senktide group did not. The results indicate that senktide facilitated the consolidation or the expression of ELM and that the senktide effect was NK3-R dependent.