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Jin SW, Ha HS, Lee I. Selective reactivation of value- and place-dependent information during sharp-wave ripples in the intermediate and dorsal hippocampus. SCIENCE ADVANCES 2024; 10:eadn0416. [PMID: 39110810 PMCID: PMC11305392 DOI: 10.1126/sciadv.adn0416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Accepted: 06/26/2024] [Indexed: 08/10/2024]
Abstract
Reactivating place cells during sharp-wave ripples in the hippocampus is important for memory consolidation. However, whether hippocampal reactivation is affected by the values of events experienced by the animal is largely unknown. Here, we investigated whether place cells in the dorsal (dHP) and intermediate hippocampus (iHP) of rats are differentially reactivated depending on the value associated with a place during the learning of places associated with higher-value rewards in a T-maze. Place cells in the iHP representing the high-value location were reactivated significantly more frequently than those representing the low-value location, characteristics not observed in the dHP. In contrast, the activities of place cells in the dHP coding the routes leading to high-value locations were replayed more than those in the iHP. Our findings suggest that value-based differential reactivation patterns along the septotemporal axis of the hippocampus may play essential roles in optimizing goal-directed spatial learning for maximal reward.
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Affiliation(s)
| | - Hee-Seung Ha
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Korea
| | - Inah Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Korea
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2
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Whitley K, Briggs SB, Sharma K, Parent MB. Don't ignore the middle: Distinct mnemonic functions of intermediate hippocampus. Hippocampus 2024. [PMID: 39096197 DOI: 10.1002/hipo.23629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 06/21/2024] [Accepted: 07/18/2024] [Indexed: 08/05/2024]
Abstract
The dorsal region of the hippocampus (dHC) mediates many of the mnemonic functions traditionally associated with the hippocampus proper, such as spatial and episodic memory, whereas ventral hippocampus (vHC) has been extensively implicated in emotional memory and motivational processes. By contrast, the functions of the intermediate hippocampus (iHC) are far less understood. In this study, we aimed to investigate the mnemonic functions of iHC by reversibly inactivating iHC prior to testing memory in behavioral tasks dependent on the integrity of dHC, iHC, or vHC, namely, rapid place water maze, inhibitory avoidance, spontaneous alternation, and temporal ordering of odors. Given our previous findings showing that dHC and vHC are involved in mnemonic control of ingestive behavior, we also assessed the effects of iHC inactivation on sucrose intake. The results showed that pharmacological inhibition of iHC impairs rapid place water maze memory, which has been previously shown to be dependent on iHC but not dHC or vHC. iHC inactivation does not impact memory dependent on dHC (spontaneous alternation), vHC (temporal odor memory), or either dHC or vHC (inhibitory avoidance), and only modestly affects sucrose intake. These findings provide support for the involvement of iHC in mnemonic functions that are distinct from dHC and vHC and highlight the need to further advance our understanding of the functions of this hippocampal region that has been relatively understudied.
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Affiliation(s)
- Kathryn Whitley
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA
| | - Sherri B Briggs
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA
| | - Karan Sharma
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA
| | - Marise B Parent
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA
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3
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Qiu Y, Li H, Liao J, Chen K, Wu X, Liu B, Huang R. Forming cognitive maps for abstract spaces: the roles of the human hippocampus and orbitofrontal cortex. Commun Biol 2024; 7:517. [PMID: 38693344 PMCID: PMC11063219 DOI: 10.1038/s42003-024-06214-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 04/18/2024] [Indexed: 05/03/2024] Open
Abstract
How does the human brain construct cognitive maps for decision-making and inference? Here, we conduct an fMRI study on a navigation task in multidimensional abstract spaces. Using a deep neural network model, we assess learning levels and categorized paths into exploration and exploitation stages. Univariate analyses show higher activation in the bilateral hippocampus and lateral prefrontal cortex during exploration, positively associated with learning level and response accuracy. Conversely, the bilateral orbitofrontal cortex (OFC) and retrosplenial cortex show higher activation during exploitation, negatively associated with learning level and response accuracy. Representational similarity analysis show that the hippocampus, entorhinal cortex, and OFC more accurately represent destinations in exploitation than exploration stages. These findings highlight the collaboration between the medial temporal lobe and prefrontal cortex in learning abstract space structures. The hippocampus may be involved in spatial memory formation and representation, while the OFC integrates sensory information for decision-making in multidimensional abstract spaces.
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Affiliation(s)
- Yidan Qiu
- School of Psychology; Center for the Study of Applied Psychology; Key Laboratory of Mental Health and Cognitive Science of Guangdong Province; Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education; South China Normal University, Guangzhou, 510631, China
| | - Huakang Li
- School of Computer Science and Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Jiajun Liao
- School of Psychology; Center for the Study of Applied Psychology; Key Laboratory of Mental Health and Cognitive Science of Guangdong Province; Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education; South China Normal University, Guangzhou, 510631, China
| | - Kemeng Chen
- School of Psychology; Center for the Study of Applied Psychology; Key Laboratory of Mental Health and Cognitive Science of Guangdong Province; Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education; South China Normal University, Guangzhou, 510631, China
| | - Xiaoyan Wu
- School of Psychology; Center for the Study of Applied Psychology; Key Laboratory of Mental Health and Cognitive Science of Guangdong Province; Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education; South China Normal University, Guangzhou, 510631, China
| | - Bingyi Liu
- School of Psychology; Center for the Study of Applied Psychology; Key Laboratory of Mental Health and Cognitive Science of Guangdong Province; Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education; South China Normal University, Guangzhou, 510631, China
| | - Ruiwang Huang
- School of Psychology; Center for the Study of Applied Psychology; Key Laboratory of Mental Health and Cognitive Science of Guangdong Province; Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education; South China Normal University, Guangzhou, 510631, China.
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4
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El Mahmoudi N, Laurent C, Péricat D, Watabe I, Lapotre A, Jacob PY, Tonetto A, Tighilet B, Sargolini F. Long-lasting spatial memory deficits and impaired hippocampal plasticity following unilateral vestibular loss. Prog Neurobiol 2023; 223:102403. [PMID: 36821981 DOI: 10.1016/j.pneurobio.2023.102403] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 11/25/2022] [Accepted: 01/04/2023] [Indexed: 02/23/2023]
Abstract
Unilateral vestibular loss (UVL) induces a characteristic vestibular syndrome composed of various posturo-locomotor, oculomotor, vegetative and perceptivo-cognitive symptoms. Functional deficits are progressively recovered over time during vestibular compensation, that is supported by the expression of multiscale plasticity mechanisms. While the dynamic of post-UVL posturo-locomotor and oculomotor deficits is well characterized, the expression over time of the cognitive deficits, and in particular spatial memory deficits, is still debated. In this study we aimed at investigating spatial memory deficits and their recovery in a rat model of unilateral vestibular neurectomy (UVN), using a wide spectrum of behavioral tasks. In parallel, we analyzed markers of hippocampal plasticity involved in learning and memory. Our results indicate the UVN affects all domains of spatial memory, from working memory to reference memory and object-in-place recognition. These deficits are associated with long-lasting impaired plasticity in the ipsilesional hippocampus. These results highlight the crucial role of symmetrical vestibular information in spatial memory and contribute to a better understanding of the cognitive disorders observed in vestibular patients.
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Affiliation(s)
- Nada El Mahmoudi
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France.
| | - Célia Laurent
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - David Péricat
- Université de Toulouse Paul Sabatier -CNRS, Institut de pharmacologie et de biologie structurale, Toulouse, France
| | - Isabelle Watabe
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Agnès Lapotre
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Pierre-Yves Jacob
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Alain Tonetto
- Aix Marseille Université-CNRS, Centrale Marseille, FSCM (FR 1739), PRATIM, F-13397 Marseille, France
| | - Brahim Tighilet
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Francesca Sargolini
- Aix-Marseille Université -CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France.
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5
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Differential encoding of place value between the dorsal and intermediate hippocampus. Curr Biol 2021; 31:3053-3072.e5. [DOI: 10.1016/j.cub.2021.04.073] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/08/2021] [Accepted: 04/28/2021] [Indexed: 01/08/2023]
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Niedecker RW, Kloc ML, Holmes GL, Barry JM. Effects of early life seizures on coordination of hippocampal-prefrontal networks: Influence of sex and dynamic brain states. Epilepsia 2021; 62:1701-1714. [PMID: 34002378 PMCID: PMC8260466 DOI: 10.1111/epi.16927] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Early life seizures (ELSs) alter activity-dependent maturation of neuronal circuits underlying learning and memory. The pathophysiological mechanisms underpinning seizure-induced cognitive impairment are not fully understood, and critical variables such as sex and dynamic brain states with regard to cognitive outcomes have not been explored. We hypothesized that in comparison to control (CTL) rats, ELS rats would exhibit deficits in spatial cognition correlating with impaired dynamic neural signal coordination between the hippocampus and medial prefrontal cortex (mPFC). METHODS Male and female rat pups were given 50 flurothyl-induced seizures over 10 days starting at postnatal Day 15. As adults, spatial cognition was tested through active avoidance on a rotating arena. Microwire tetrodes were implanted in the mPFC and CA1 subfield. Single cells and local field potentials were recorded and analyzed in each region during active avoidance and sleep. RESULTS ELS males exhibited avoidance impairments, whereas female rats were unaffected. During avoidance, hippocampus-mPFC coherence was higher in CTL females than CTL males across bandwidths. In comparison to CTL males, ELS male learners exhibit increased coherence within theta bandwidth as well as altered burst-timing in mPFC cell activity. Hippocampus-mPFC coherence levels are predictive of cognitive outcome in the active avoidance spatial task. SIGNIFICANCE Spatial cognitive outcome post-ELS is sex-dependent, as females fare better than males. ELS males that learn the task exhibit increased mPFC coherence levels at low-theta frequency, which may compensate for ELS effects on mPFC cell timing. These results suggest that coherence may serve as a biomarker for spatial cognitive outcome post-ELS and emphasize the significance of analyzing sex and dynamic cognition as variables in understanding seizure effects on the developing brain.
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Affiliation(s)
- Rhys W Niedecker
- Department of Neurological Sciences, Epilepsy Development and Cognition Group, Larner College of Medicine, University of Vermont, Burlington, VT, USA
| | - Michelle L Kloc
- Department of Neurological Sciences, Epilepsy Development and Cognition Group, Larner College of Medicine, University of Vermont, Burlington, VT, USA
| | - Gregory L Holmes
- Department of Neurological Sciences, Epilepsy Development and Cognition Group, Larner College of Medicine, University of Vermont, Burlington, VT, USA
| | - Jeremy M Barry
- Department of Neurological Sciences, Epilepsy Development and Cognition Group, Larner College of Medicine, University of Vermont, Burlington, VT, USA
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Context-Dependent Multiplexing by Individual VTA Dopamine Neurons. J Neurosci 2020; 40:7489-7509. [PMID: 32859713 DOI: 10.1523/jneurosci.0502-20.2020] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 07/25/2020] [Accepted: 08/03/2020] [Indexed: 01/13/2023] Open
Abstract
Dopamine (DA) neurons of the VTA track cues and rewards to generate a reward prediction error signal during Pavlovian conditioning. Here we explored how these neurons respond to a self-paced, operant task in freely moving mice. The animal could trigger a reward-predicting cue by remaining in a specific location of an operant box for a brief time before moving to a spout for reward collection. VTA DA neurons were identified using DAT-Cre male mice that carried an optrode with minimal impact on the behavioral task. In vivo single-unit recordings revealed transient fast spiking responses to the cue and reward in correct trials, while for incorrect ones the activity paused, reflecting positive and negative error signals of a reward prediction. In parallel, a majority of VTA DA neurons simultaneously encoded multiple actions (e.g., movement velocity, acceleration, distance to goal, and licking) in sustained slow firing modulation. Applying a GLM, we show that such multiplexed encoding of rewarding and motor variables by individual DA neurons was only apparent while the mouse was engaged in the task. Downstream targets may exploit such goal-directed multiplexing of VTA DA neurons to adjust actions to optimize the task's outcome.SIGNIFICANCE STATEMENT VTA DA neurons code for multiple functions, including the reward prediction error but also motivation and locomotion. Here we show that about half of the recorded VTA DA neurons perform multiplexing: they exploit the phasic and tonic activity modes to encode, respectively, the cue/reward responses and motor parameters, most prominently when the mouse engages in a self-paced operand task. VTA non-DA neurons, by contrast, encode motor parameters regardless of task engagement.
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8
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Meyer-Mueller C, Jacob PY, Montenay JY, Poitreau J, Poucet B, Chaillan FA. Dorsal, but not ventral, hippocampal inactivation alters deliberation in rats. Behav Brain Res 2020; 390:112622. [DOI: 10.1016/j.bbr.2020.112622] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/05/2020] [Accepted: 03/24/2020] [Indexed: 02/05/2023]
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9
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Contreras M, Pelc T, Llofriu M, Weitzenfeld A, Fellous JM. The ventral hippocampus is involved in multi-goal obstacle-rich spatial navigation. Hippocampus 2018; 28:853-866. [PMID: 30067283 DOI: 10.1002/hipo.22993] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 05/06/2018] [Accepted: 05/31/2018] [Indexed: 11/06/2022]
Abstract
A large body of evidence shows that the hippocampus is necessary for successful spatial navigation. Various studies have shown anatomical and functional differences between the dorsal (DHC) and ventral (VHC) portions of this structure. The DHC is primarily involved in spatial navigation and contains cells with small place fields. The VHC is primarily involved in context and emotional encoding contains cells with large place fields and receives major projections from the medial prefrontal cortex. In the past, spatial navigation experiments have used relatively simple tasks that may not have required a strong coordination along the dorsoventral hippocampal axis. In this study, we tested the hypothesis that the DHC and VHC may be critical for goal-directed navigation in obstacle-rich environments. We used a learning task in which animals memorize the location of a set of rewarded feeders, and recall these locations in the presence of small or large obstacles. We report that bilateral DHC or VHC inactivation impaired spatial navigation in both large and small obstacle conditions. Importantly, this impairment did not result from a deficit in the spatial memory for the set of feeders (i.e., recognition of the goal locations) because DHC or VHC inactivation did not affect recall performance when there was no obstacle on the maze. We also show that the behavioral performance of the animals was correlated with several measures of maze complexity and that these correlations were significantly affected by inactivation only in the large object condition. These results suggest that as the complexity of the environment increases, both DHC and VHC are required for spatial navigation.
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Affiliation(s)
- Marco Contreras
- Department of Psychology, University of Arizona, Tucson, Arizona
| | - Tatiana Pelc
- Department of Psychology, University of Arizona, Tucson, Arizona
| | - Martin Llofriu
- Department of Computer Science and Engineering, University of South Florida, Tampa, Florida
| | - Alfredo Weitzenfeld
- Department of Computer Science and Engineering, University of South Florida, Tampa, Florida
| | - Jean-Marc Fellous
- Department of Psychology, University of Arizona, Tucson, Arizona.,Department of Applied Mathematics, University of Arizona, Tucson, Arizona
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10
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11
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Quinolinic acid injection in mouse medial prefrontal cortex affects reversal learning abilities, cortical connectivity and hippocampal synaptic plasticity. Sci Rep 2016; 6:36489. [PMID: 27819338 PMCID: PMC5098239 DOI: 10.1038/srep36489] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 10/17/2016] [Indexed: 12/22/2022] Open
Abstract
Intracerebral injection of the excitotoxic, endogenous tryptophan metabolite, quinolinic acid (QA), constitutes a chemical model of neurodegenerative brain disease. Complementary techniques were combined to examine the consequences of QA injection into medial prefrontal cortex (mPFC) of C57BL6 mice. In accordance with the NMDAR-mediated synapto- and neurotoxic action of QA, we found an initial increase in excitability and an augmentation of hippocampal long-term potentiation, converting within two weeks into a reduction and impairment, respectively, of these processes. QA-induced mPFC excitotoxicity impaired behavioral flexibility in a reversal variant of the hidden-platform Morris water maze (MWM), whereas regular, extended MWM training was unaffected. QA-induced mPFC damage specifically affected the spatial-cognitive strategies that mice use to locate the platform during reversal learning. These behavioral and cognitive defects coincided with changes in cortical functional connectivity (FC) and hippocampal neuroplasticity. FC between various cortical regions was assessed by resting-state fMRI (rsfMRI) methodology, and mice that had received QA injection into mPFC showed increased FC between various cortical regions. mPFC and hippocampus (HC) are anatomically as well as functionally linked as part of a cortical network that controls higher-order cognitive functions. Together, these observations demonstrate the central functional importance of rodent mPFC as well as the validity of QA-induced mPFC damage as a preclinical rodent model of the early stages of neurodegeneration.
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Taylor CJ, Ohline SM, Moss T, Ulrich K, Abraham WC. The persistence of long-term potentiation in the projection from ventral hippocampus to medial prefrontal cortex in awake rats. Eur J Neurosci 2016; 43:811-22. [PMID: 26750170 DOI: 10.1111/ejn.13167] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 12/07/2015] [Accepted: 12/22/2015] [Indexed: 12/12/2022]
Abstract
A potentially vital pathway in the processing of spatial memory is the pathway from ventral hippocampus to medial prefrontal cortex (vHPC-mPFC). To assess long-term potentiation (LTP) induction and maintenance across days in this pathway, the effects of several induction paradigms were compared in awake, freely moving rats. Two different high-frequency stimulation (HFS) protocols generated LTP lasting no longer than 1 week. However, after delivering HFS on three consecutive days, LTP lasted an average of 20 days, due mainly to the greater initial induction. Thus the pathway does not require extensive multi-day stimulation to induce LTP, as for other intra-neocortical pathways, but also it does not exhibit the extremely long-lasting and stable LTP previously observed in area CA1 and the dentate gyrus. By using bilaterally placed stimulating and recording electrodes, we found that HFS in one vHPC generated responses and LTP in the contralateral mPFC, even when the ipsilateral mPFC was inactivated by CNQX. We attribute this crossed response to a polysynaptic pathway from the vHPC to the contralateral mPFC. Finally, we found that repeated overnight exposure to an enriched environment also potentiated the vHPC-mPFC response, but this too was a transient effect lasting < 9 days, declining to baseline even before the enriched environment treatment was completed. Overall, these findings are consistent with the view that potentiation of vHPC-mPFC pathway may play a key role in promoting the hippocampus-mPFC interplay that, over days, leads to long-term storage in the frontal cortex of memories that are independent of the hippocampus.
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Affiliation(s)
- Chanel J Taylor
- Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
| | - Shane M Ohline
- Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand.,Brain Research New Zealand, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
| | - Timothy Moss
- Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
| | - Katharina Ulrich
- Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand.,Brain Health Research Centre, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand.,Brain Research New Zealand, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
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13
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How does the hippocampus shape decisions? Neurobiol Learn Mem 2015; 125:93-7. [DOI: 10.1016/j.nlm.2015.08.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 07/30/2015] [Accepted: 08/11/2015] [Indexed: 11/20/2022]
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14
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Schlichting ML, Preston AR. Memory integration: neural mechanisms and implications for behavior. Curr Opin Behav Sci 2015; 1:1-8. [PMID: 25750931 DOI: 10.1016/j.cobeha.2014.07.005] [Citation(s) in RCA: 214] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Everyday behaviors require a high degree of flexibility, in which prior knowledge is applied to inform behavior in new situations. Such flexibility is thought to be supported in part by memory integration, a process whereby related memories become interconnected in the brain through recruitment of overlapping neuronal populations. Recent advances in cognitive and behavioral neuroscience highlight the importance of a hippocampal-medial prefrontal circuit in memory integration. Emerging evidence suggests that abstracted representations in medial prefrontal cortex guide reactivation of related memories during new encoding events, thus promoting hippocampal integration of related experiences. Moreover, recent work indicates that integrated memories are called upon during novel situations to facilitate a host of behaviors, from spatial navigation to imagination.
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Affiliation(s)
- Margaret L Schlichting
- Department of Psychology, The University of Texas at Austin, 1 University Station A8000, Austin, TX 78712, United States ; Center for Learning and Memory, The University of Texas at Austin, 1 University Station C7000, Austin, TX 78712, United States
| | - Alison R Preston
- Department of Psychology, The University of Texas at Austin, 1 University Station A8000, Austin, TX 78712, United States ; Center for Learning and Memory, The University of Texas at Austin, 1 University Station C7000, Austin, TX 78712, United States ; Department of Neuroscience, The University of Texas at Austin, 1 University Station C7000, Austin, TX 78712, United States
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Fernandez F, Reeves RH. Assessing cognitive improvement in people with Down syndrome: important considerations for drug-efficacy trials. Handb Exp Pharmacol 2015; 228:335-80. [PMID: 25977089 DOI: 10.1007/978-3-319-16522-6_12] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Experimental research over just the past decade has raised the possibility that learning deficits connected to Down syndrome (DS) might be effectively managed by medication. In the current chapter, we touch on some of the work that paved the way for these advances and discuss the challenges associated with translating them. In particular, we highlight sources of phenotypic variability in the DS population that are likely to impact performance assessments. Throughout, suggestions are made on how to detect meaningful changes in cognitive-adaptive function in people with DS during drug treatment. The importance of within-subjects evaluation is emphasized.
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Affiliation(s)
- Fabian Fernandez
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA,
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Engeln M, De Deurwaerdère P, Li Q, Bezard E, Fernagut PO. Widespread Monoaminergic Dysregulation of Both Motor and Non-Motor Circuits in Parkinsonism and Dyskinesia. Cereb Cortex 2014; 25:2783-92. [DOI: 10.1093/cercor/bhu076] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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