1
|
Sekeres MJ, Schomaker J, Nadel L, Tse D. To update or to create? The influence of novelty and prior knowledge on memory networks. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230238. [PMID: 38853571 PMCID: PMC11343309 DOI: 10.1098/rstb.2023.0238] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 06/11/2024] Open
Abstract
Schemas are foundational mental structures shaped by experience. They influence behaviour, guide the encoding of new memories and are shaped by associated information. The adaptability of memory schemas facilitates the integration of new information that aligns with existing knowledge structures. First, we discuss how novel information consistent with an existing schema can be swiftly assimilated when presented. This cognitive updating is facilitated by the interaction between the hippocampus and the prefrontal cortex. Second, when novel information is inconsistent with the schema, it likely engages the hippocampus to encode the information as part of an episodic memory trace. Third, novelty may enhance hippocampal dopamine through either the locus coeruleus or ventral tegmental area pathways, with the pathway involved potentially depending on the type of novelty encountered. We propose a gradient theory of schema and novelty to elucidate the neural processes by which schema updating or novel memory traces are formed. It is likely that experiences vary along a familiarity-novelty continuum, and the degree to which new experiences are increasingly novel will guide whether memory for a new experience either integrates into an existing schema or prompts the creation of a new cognitive framework. This article is part of the theme issue 'Long-term potentiation: 50 years on'.
Collapse
Affiliation(s)
- Melanie J. Sekeres
- School of Psychology, University of Ottawa, Ottawa, OntarioK1N 6N5, Canada
| | - Judith Schomaker
- Health, Medical & Neuropsychology, Leiden University, Leiden2333 AK, The Netherlands
- Leiden Institute for Brain and Cognition, Leiden, The Netherlands
| | - Lynn Nadel
- Department of Psychology, University of Arizona, Tucson, AZ85721, USA
| | - Dorothy Tse
- Department of Psychology, Edge Hill University, OrmskirkL39 4QP, UK
| |
Collapse
|
2
|
Lima KR, Neves BHSD, Sigaran GJ, Rosa ACDSD, Gomes GCM, Gomes de Gomes M, Mello-Carpes PB. Acute physical exercise prevents memory amnesia caused by protein synthesis inhibition in rats' hippocampus. Neurochem Int 2024; 176:105740. [PMID: 38636905 DOI: 10.1016/j.neuint.2024.105740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 03/29/2024] [Accepted: 04/09/2024] [Indexed: 04/20/2024]
Abstract
The benefits of physical exercise (PE) on memory consolidation have been well-documented in both healthy and memory-impaired animals. However, the underlying mechanisms through which PE exerts these effects are still unclear. In this study, we aimed to investigate the role of hippocampal protein synthesis in memory modulation by acute PE in rats. After novel object recognition (NOR) training, rats were subjected to a 30-min moderate-intensity acute PE on the treadmill, while control animals did not undergo any procedures. Using anisomycin (ANI) and rapamycin (RAPA), compounds that inhibit protein synthesis through different mechanisms, we manipulated protein synthesis in the CA1 region of the hippocampus to examine its contribution to memory consolidation. Memory was assessed on days 1, 7, and 14 post-training. Our results showed that inhibiting protein synthesis by ANI or RAPA impaired NOR memory consolidation in control animals. However, acute PE prevented this impairment without affecting memory persistence. We also evaluated brain-derived neurotrophic factor (BDNF) levels after acute PE at 0.5h, 2h, and 12h afterward and found no differences in levels compared to animals that did not engage in acute PE or were only habituated to the treadmill. Therefore, our findings suggest that acute PE could serve as a non-pharmacological intervention to enhance memory consolidation and prevent memory loss in conditions associated with hippocampal protein synthesis inhibition. This mechanism appears not to depend on BDNF synthesis in the early hours after exercise.
Collapse
Affiliation(s)
- Karine Ramires Lima
- Physiology Research Group, Stress, Memory and Behavior Lab, Federal University of Pampa, Uruguaiana, RS, Brazil
| | - Ben-Hur Souto das Neves
- Physiology Research Group, Stress, Memory and Behavior Lab, Federal University of Pampa, Uruguaiana, RS, Brazil
| | - Gabriela Jaques Sigaran
- Physiology Research Group, Stress, Memory and Behavior Lab, Federal University of Pampa, Uruguaiana, RS, Brazil
| | | | | | - Marcelo Gomes de Gomes
- Physiology Research Group, Stress, Memory and Behavior Lab, Federal University of Pampa, Uruguaiana, RS, Brazil; Center of Sciences, Tehcnologies and Health, Department of Health Sciences, Federal University of Santa Catarina, Araranguá, SC, Brazil
| | - Pâmela Billig Mello-Carpes
- Physiology Research Group, Stress, Memory and Behavior Lab, Federal University of Pampa, Uruguaiana, RS, Brazil.
| |
Collapse
|
3
|
Shi P, Chen W, Li J, Weng Y, Zhang M, Zheng X. Novelty-retrieval-extinction paradigm to decrease high-intensity fear memory recurrence. J Affect Disord 2024; 354:26-35. [PMID: 38452938 DOI: 10.1016/j.jad.2024.02.088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 02/13/2024] [Accepted: 02/26/2024] [Indexed: 03/09/2024]
Abstract
BACKGROUND The retrieval-extinction paradigm based on memory reconsolidation can prevent fear memory recurrence more effectively than the extinction paradigm. High-intensity fear memories tend to resist reconsolidation. Novelty-retrieval-extinction can promote the reconsolidation of fear memory lacking neuroplasticity in rodents; however, whether it could effectively promote high-intensity fear memory reconsolidation in humans remains unclear. METHODS Using 120 human participants, we implemented the use of the environment (novel vs. familiar) with the help of virtual reality technology. Novelty environment exploration was combined with retrieval-extinction in fear memory of two intensity levels (normal vs. high) to examine whether novelty facilitates the reconsolidation of high-intensity fear memory and prevents recurrence. Skin conductance responses were used to clarify novelty-retrieval-extinction effects at the behavioral level across three experiments. RESULTS Retrieval-extinction could prevent the reinstatement of normal-intensity fear memory; however, for high-intensity fear memory, only the novelty-retrieval-extinction could prevent recurrence; we further validated that novelty-retrieval-extinction may be effective only when the environment is novel. LIMITATIONS Although the high-intensity fear memory is higher than normal-intensity in this study, it may be insufficient relative to fear experienced in real-world contexts or by individuals with mental disorders. CONCLUSIONS To some extent, these findings indicate that the novelty-retrieval-extinction paradigm could prevent the recurrence of high-intensity fear memory, and we infer that novelty of environment may play an important role in novelty-retrieval-extinction paradigm. The results of this study have positive implications for the existing retrieval extinction paradigm and the clinical treatment of phobia.
Collapse
Affiliation(s)
- Pei Shi
- School of Psychology, South China Normal University, Guangzhou, China; Center for Studies of Psychological Application, South China Normal University, Guangzhou, China; Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Wei Chen
- School of Psychology, South China Normal University, Guangzhou, China; Center for Studies of Psychological Application, South China Normal University, Guangzhou, China; Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Junjiao Li
- College of Teacher Education, Guangdong University of Education, Guangzhou, China
| | - Yuhan Weng
- School of Psychology, South China Normal University, Guangzhou, China; Center for Studies of Psychological Application, South China Normal University, Guangzhou, China; Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Mingyue Zhang
- School of Psychology, South China Normal University, Guangzhou, China; Center for Studies of Psychological Application, South China Normal University, Guangzhou, China; Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Xifu Zheng
- School of Psychology, South China Normal University, Guangzhou, China; Center for Studies of Psychological Application, South China Normal University, Guangzhou, China; Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China.
| |
Collapse
|
4
|
Cabrera Y, Koymans KJ, Poe GR, Kessels HW, Van Someren EJW, Wassing R. Overnight neuronal plasticity and adaptation to emotional distress. Nat Rev Neurosci 2024; 25:253-271. [PMID: 38443627 DOI: 10.1038/s41583-024-00799-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2024] [Indexed: 03/07/2024]
Abstract
Expressions such as 'sleep on it' refer to the resolution of distressing experiences across a night of sound sleep. Sleep is an active state during which the brain reorganizes the synaptic connections that form memories. This Perspective proposes a model of how sleep modifies emotional memory traces. Sleep-dependent reorganization occurs through neurophysiological events in neurochemical contexts that determine the fates of synapses to grow, to survive or to be pruned. We discuss how low levels of acetylcholine during non-rapid eye movement sleep and low levels of noradrenaline during rapid eye movement sleep provide a unique window of opportunity for plasticity in neuronal representations of emotional memories that resolves the associated distress. We integrate sleep-facilitated adaptation over three levels: experience and behaviour, neuronal circuits, and synaptic events. The model generates testable hypotheses for how failed sleep-dependent adaptation to emotional distress is key to mental disorders, notably disorders of anxiety, depression and post-traumatic stress with the common aetiology of insomnia.
Collapse
Affiliation(s)
- Yesenia Cabrera
- Department of Integrative Biology and Physiology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Karin J Koymans
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Gina R Poe
- Department of Integrative Biology and Physiology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Helmut W Kessels
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
- Department of Synaptic Plasticity and Behaviour, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Society for Arts and Sciences, Amsterdam, Netherlands
| | - Eus J W Van Someren
- Department of Sleep and Cognition, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Society for Arts and Sciences, Amsterdam, Netherlands
- Department of Integrative Neurophysiology and Psychiatry, VU University, Amsterdam UMC, Amsterdam, Netherlands
- Center for Neurogenomics and Cognitive Research, VU University, Amsterdam UMC, Amsterdam, Netherlands
| | - Rick Wassing
- Sleep and Circadian Research, Woolcock Institute of Medical Research, Macquarie University, Sydney, New South Wales, Australia.
- School of Psychological Sciences, Faculty of Medicine Health and Human Sciences, Macquarie University, Sydney, New South Wales, Australia.
- Sydney Local Health District, Sydney, New South Wales, Australia.
| |
Collapse
|
5
|
Lima KR, Alves N, Lopes LF, Picua SS, da Silva de Vargas L, Daré LR, Ramborger B, Roehrs R, de Gomes MG, Mello-Carpes PB. Novelty facilitates the persistence of aversive memory extinction by dopamine regulation in the hippocampus and ventral tegmental area. Prog Neuropsychopharmacol Biol Psychiatry 2023; 127:110832. [PMID: 37463639 DOI: 10.1016/j.pnpbp.2023.110832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 07/20/2023]
Abstract
Aversive memory extinction comprises a novel learning that blocks retrieving a previously formed traumatic memory. In this sense, aversive memory extinction is an excellent tool for decreasing fear responses. However, this tool it's not effective in the long term because of original memory spontaneous recovery. Thus, searching for alternative strategies that strengthen extinction learning is essential. In the current study, we evaluated the effects of a novel context (i.e., novelty) exposure on aversive memory extinction enhancement over days and the dopaminergic system requirement. Given the purpose, experiments were conducted using 3-month-old male Wistar rats. Animals were trained in inhibitory avoidance (IA). Twenty-four hours later, rats were submitted to a weak extinction protocol. Still, 30 min before the first extinction session, animals were submitted to an exploration of a novel context for 5 min. After, memory retention and persistence were evaluated 24 h, 3, 7, 14, and 21 days later. The exposition of a novel context caused a decrease in aversive responses in all days analyzed and an increase in dopamine levels in the hippocampus. The intrahippocampal infusion of dopamine in the CA1 area or the stimulation of the ventral tegmental area (VTA) by a glutamatergic agonist (NMDA) showed similar effects of novelty. In contrast, VTA inhibition by a gabaergic agonist (muscimol) impaired the persistence of extinction learning induced by novelty exposition and caused a decrease in hippocampal dopamine levels. In summary, we show that novel context exposure promotes persistent aversive memory extinction, revealing the significant role of the dopaminergic system.
Collapse
Affiliation(s)
- Karine Ramires Lima
- Physiology Research Group, Stress, Memory and Behavior Lab, Federal University of Pampa, Uruguaiana, RS, Brazil
| | - Niege Alves
- Physiology Research Group, Stress, Memory and Behavior Lab, Federal University of Pampa, Uruguaiana, RS, Brazil
| | - Luiza Freitas Lopes
- Physiology Research Group, Stress, Memory and Behavior Lab, Federal University of Pampa, Uruguaiana, RS, Brazil
| | - Steffanie Severo Picua
- Physiology Research Group, Stress, Memory and Behavior Lab, Federal University of Pampa, Uruguaiana, RS, Brazil
| | - Liane da Silva de Vargas
- Physiology Research Group, Stress, Memory and Behavior Lab, Federal University of Pampa, Uruguaiana, RS, Brazil
| | | | - Bruna Ramborger
- Interdisciplinary Group of Research in Teaching Practice, Federal University of Pampa, Uruguaiana, RS, Brazil
| | - Rafael Roehrs
- Interdisciplinary Group of Research in Teaching Practice, Federal University of Pampa, Uruguaiana, RS, Brazil
| | - Marcelo Gomes de Gomes
- Physiology Research Group, Stress, Memory and Behavior Lab, Federal University of Pampa, Uruguaiana, RS, Brazil
| | - Pâmela Billig Mello-Carpes
- Physiology Research Group, Stress, Memory and Behavior Lab, Federal University of Pampa, Uruguaiana, RS, Brazil.
| |
Collapse
|
6
|
Cahill MK, Perez YR, Larpthaveesarp A, Etchenique R, Poskanzer KE. A Photoactivatable Norepinephrine for Probing Adrenergic Neural Circuits. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.13.566764. [PMID: 38014204 PMCID: PMC10680792 DOI: 10.1101/2023.11.13.566764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Norepinephrine (NE) is a critical neuromodulator that mediates a wide range of behavior and neurophysiology, including attention, arousal, plasticity, and memory consolidation. A major source of NE is the brainstem nucleus the locus coeruleus (LC), which sends widespread projections throughout the central nervous system (CNS). Efforts to dissect this complex noradrenergic circuitry have driven the development of many tools that detect endogenous NE or modulate widespread NE release via LC activation and inhibition. While these tools have enabled research that elucidates physiological roles of NE, additional tools to probe these circuits with a higher degree of spatial precision could enable a finer delineation of function. Here, we describe the synthesis and chemical properties of a photo-activatable NE, [Ru(bpy) 2 (PMe 3 )(NE)]PF 6 (RuBi-NE). We validate the one-photon (1P) release of NE using whole-cell patch clamp electrophysiology in acute mouse brain slices containing the LC. We show that a 10 ms pulse of blue light, in the presence of RuBi-NE, briefly modulates the firing rate of LC neurons via α-2 adrenergic receptors. The development of a photo-activatable NE that can be released with light in the visible spectrum provides a new tool for fine-grained mapping of complex noradrenergic circuits, as well as the ability to probe how NE acts on non-neuronal cells in the CNS.
Collapse
|
7
|
Prokopiou PC, Engels-Domínguez N, Schultz AP, Sepulcre J, Koops EA, Papp KV, Marshall GA, Normandin MD, El Fakhri G, Rentz D, Sperling RA, Johnson KA, Jacobs HIL. Association of Novelty-Related Locus Coeruleus Function With Entorhinal Tau Deposition and Memory Decline in Preclinical Alzheimer Disease. Neurology 2023; 101:e1206-e1217. [PMID: 37491329 PMCID: PMC10516269 DOI: 10.1212/wnl.0000000000207646] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 05/31/2023] [Indexed: 07/27/2023] Open
Abstract
BACKGROUND AND OBJECTIVES The predictable Braak staging scheme suggests that cortical tau progression may be related to synaptically connected neurons. Animal and human neuroimaging studies demonstrated that changes in neuronal activity contribute to tau spreading. Whether similar mechanisms explain tau progression from the locus coeruleus (LC), a tiny noradrenergic brainstem nucleus involved in novelty, learning, and memory and among the earliest regions to accumulate tau, has not yet been established. We aimed to investigate whether novelty-related LC activity was associated with the accumulation of cortical tau and its implications for cognitive decline. METHODS We combined functional MRI data of a novel vs repeated face-name learning paradigm, [18F]-FTP-PET, [11C]-PiB-PET, and longitudinal cognitive data from 92 well-characterized older individuals in the Harvard Aging Brain Study. We related novelty vs repetition LC activity to cortical tau deposition and to longitudinal decline in memory, executive function, and the Preclinical Alzheimer Disease Cognitive Composite (version 5; PACC5). Structural equation modeling was used to examine whether entorhinal cortical (EC) tau mediated the relationship between LC activity and cognitive decline and whether this depended on beta-amyloid deposition. RESULTS The participants' average age at baseline was 69.67 ± 10.14 years. Fifty-one participants were female. Ninety-one participants were cognitively normal (CDR global = 0), and one participant had mild cognitive impairment (CDR global = 0.5) at baseline. Lower novelty-related LC activity was specifically related to greater tau deposition in the medial-lateral temporal cortex and steeper memory decline. LC activity during novelty vs repetition was not related to executive dysfunction or decline on the PACC5. The relationship between LC activity and memory decline was partially mediated by EC tau, particularly in individuals with elevated beta-amyloid deposition. DISCUSSION Our results suggested that lower novelty-related LC activity is associated with the emergence of EC tau and that the downstream effects of this LC-EC pathway on memory decline also require the presence of elevated beta-amyloid. Longitudinal studies are required to investigate whether optimal LC activity has the potential to delay tau spread and memory decline, which may have implications for designing targeted interventions promoting resilience.
Collapse
Affiliation(s)
- Prokopis C Prokopiou
- From the Gordon Center for Medical Imaging (P.C.P., N.E.-D., J.S., E.A.K., M.D.N., G.E.F., K.A.J., H.I.L.J.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston; Faculty of Health (N.E.-D., H.I.L.J.), Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, The Netherlands; Department of Neurology (A.P.S., K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Massachusetts General Hospital, Harvard Medical School; The Athinoula A. Martinos Center for Biomedical Imaging (A.P.S.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School; and Center for Alzheimer Research and Treatment (K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Nina Engels-Domínguez
- From the Gordon Center for Medical Imaging (P.C.P., N.E.-D., J.S., E.A.K., M.D.N., G.E.F., K.A.J., H.I.L.J.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston; Faculty of Health (N.E.-D., H.I.L.J.), Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, The Netherlands; Department of Neurology (A.P.S., K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Massachusetts General Hospital, Harvard Medical School; The Athinoula A. Martinos Center for Biomedical Imaging (A.P.S.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School; and Center for Alzheimer Research and Treatment (K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Aaron P Schultz
- From the Gordon Center for Medical Imaging (P.C.P., N.E.-D., J.S., E.A.K., M.D.N., G.E.F., K.A.J., H.I.L.J.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston; Faculty of Health (N.E.-D., H.I.L.J.), Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, The Netherlands; Department of Neurology (A.P.S., K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Massachusetts General Hospital, Harvard Medical School; The Athinoula A. Martinos Center for Biomedical Imaging (A.P.S.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School; and Center for Alzheimer Research and Treatment (K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Jorge Sepulcre
- From the Gordon Center for Medical Imaging (P.C.P., N.E.-D., J.S., E.A.K., M.D.N., G.E.F., K.A.J., H.I.L.J.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston; Faculty of Health (N.E.-D., H.I.L.J.), Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, The Netherlands; Department of Neurology (A.P.S., K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Massachusetts General Hospital, Harvard Medical School; The Athinoula A. Martinos Center for Biomedical Imaging (A.P.S.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School; and Center for Alzheimer Research and Treatment (K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Elouise A Koops
- From the Gordon Center for Medical Imaging (P.C.P., N.E.-D., J.S., E.A.K., M.D.N., G.E.F., K.A.J., H.I.L.J.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston; Faculty of Health (N.E.-D., H.I.L.J.), Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, The Netherlands; Department of Neurology (A.P.S., K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Massachusetts General Hospital, Harvard Medical School; The Athinoula A. Martinos Center for Biomedical Imaging (A.P.S.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School; and Center for Alzheimer Research and Treatment (K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Kathryn V Papp
- From the Gordon Center for Medical Imaging (P.C.P., N.E.-D., J.S., E.A.K., M.D.N., G.E.F., K.A.J., H.I.L.J.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston; Faculty of Health (N.E.-D., H.I.L.J.), Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, The Netherlands; Department of Neurology (A.P.S., K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Massachusetts General Hospital, Harvard Medical School; The Athinoula A. Martinos Center for Biomedical Imaging (A.P.S.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School; and Center for Alzheimer Research and Treatment (K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Gad A Marshall
- From the Gordon Center for Medical Imaging (P.C.P., N.E.-D., J.S., E.A.K., M.D.N., G.E.F., K.A.J., H.I.L.J.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston; Faculty of Health (N.E.-D., H.I.L.J.), Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, The Netherlands; Department of Neurology (A.P.S., K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Massachusetts General Hospital, Harvard Medical School; The Athinoula A. Martinos Center for Biomedical Imaging (A.P.S.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School; and Center for Alzheimer Research and Treatment (K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Marc D Normandin
- From the Gordon Center for Medical Imaging (P.C.P., N.E.-D., J.S., E.A.K., M.D.N., G.E.F., K.A.J., H.I.L.J.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston; Faculty of Health (N.E.-D., H.I.L.J.), Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, The Netherlands; Department of Neurology (A.P.S., K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Massachusetts General Hospital, Harvard Medical School; The Athinoula A. Martinos Center for Biomedical Imaging (A.P.S.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School; and Center for Alzheimer Research and Treatment (K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Georges El Fakhri
- From the Gordon Center for Medical Imaging (P.C.P., N.E.-D., J.S., E.A.K., M.D.N., G.E.F., K.A.J., H.I.L.J.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston; Faculty of Health (N.E.-D., H.I.L.J.), Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, The Netherlands; Department of Neurology (A.P.S., K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Massachusetts General Hospital, Harvard Medical School; The Athinoula A. Martinos Center for Biomedical Imaging (A.P.S.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School; and Center for Alzheimer Research and Treatment (K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Dorene Rentz
- From the Gordon Center for Medical Imaging (P.C.P., N.E.-D., J.S., E.A.K., M.D.N., G.E.F., K.A.J., H.I.L.J.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston; Faculty of Health (N.E.-D., H.I.L.J.), Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, The Netherlands; Department of Neurology (A.P.S., K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Massachusetts General Hospital, Harvard Medical School; The Athinoula A. Martinos Center for Biomedical Imaging (A.P.S.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School; and Center for Alzheimer Research and Treatment (K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Reisa A Sperling
- From the Gordon Center for Medical Imaging (P.C.P., N.E.-D., J.S., E.A.K., M.D.N., G.E.F., K.A.J., H.I.L.J.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston; Faculty of Health (N.E.-D., H.I.L.J.), Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, The Netherlands; Department of Neurology (A.P.S., K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Massachusetts General Hospital, Harvard Medical School; The Athinoula A. Martinos Center for Biomedical Imaging (A.P.S.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School; and Center for Alzheimer Research and Treatment (K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Keith A Johnson
- From the Gordon Center for Medical Imaging (P.C.P., N.E.-D., J.S., E.A.K., M.D.N., G.E.F., K.A.J., H.I.L.J.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston; Faculty of Health (N.E.-D., H.I.L.J.), Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, The Netherlands; Department of Neurology (A.P.S., K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Massachusetts General Hospital, Harvard Medical School; The Athinoula A. Martinos Center for Biomedical Imaging (A.P.S.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School; and Center for Alzheimer Research and Treatment (K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Heidi I L Jacobs
- From the Gordon Center for Medical Imaging (P.C.P., N.E.-D., J.S., E.A.K., M.D.N., G.E.F., K.A.J., H.I.L.J.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston; Faculty of Health (N.E.-D., H.I.L.J.), Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, The Netherlands; Department of Neurology (A.P.S., K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Massachusetts General Hospital, Harvard Medical School; The Athinoula A. Martinos Center for Biomedical Imaging (A.P.S.), Department of Radiology, Massachusetts General Hospital, Harvard Medical School; and Center for Alzheimer Research and Treatment (K.V.P., G.A.M., D.R., R.A.S., K.A.J.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
| |
Collapse
|
8
|
Li Y, Zhi W, Qi B, Wang L, Hu X. Update on neurobiological mechanisms of fear: illuminating the direction of mechanism exploration and treatment development of trauma and fear-related disorders. Front Behav Neurosci 2023; 17:1216524. [PMID: 37600761 PMCID: PMC10433239 DOI: 10.3389/fnbeh.2023.1216524] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/18/2023] [Indexed: 08/22/2023] Open
Abstract
Fear refers to an adaptive response in the face of danger, and the formed fear memory acts as a warning when the individual faces a dangerous situation again, which is of great significance to the survival of humans and animals. Excessive fear response caused by abnormal fear memory can lead to neuropsychiatric disorders. Fear memory has been studied for a long time, which is of a certain guiding effect on the treatment of fear-related disorders. With continuous technological innovations, the study of fear has gradually shifted from the level of brain regions to deeper neural (micro) circuits between brain regions and even within single brain regions, as well as molecular mechanisms. This article briefly outlines the basic knowledge of fear memory and reviews the neurobiological mechanisms of fear extinction and relapse, which aims to provide new insights for future basic research on fear emotions and new ideas for treating trauma and fear-related disorders.
Collapse
Affiliation(s)
- Ying Li
- College of Education, Hebei University, Baoding, China
- Laboratory of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Weijia Zhi
- Laboratory of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Bing Qi
- College of Education, Hebei University, Baoding, China
| | - Lifeng Wang
- Laboratory of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Xiangjun Hu
- College of Education, Hebei University, Baoding, China
- Laboratory of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
| |
Collapse
|
9
|
Borzello M, Ramirez S, Treves A, Lee I, Scharfman H, Stark C, Knierim JJ, Rangel LM. Assessments of dentate gyrus function: discoveries and debates. Nat Rev Neurosci 2023; 24:502-517. [PMID: 37316588 PMCID: PMC10529488 DOI: 10.1038/s41583-023-00710-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2023] [Indexed: 06/16/2023]
Abstract
There has been considerable speculation regarding the function of the dentate gyrus (DG) - a subregion of the mammalian hippocampus - in learning and memory. In this Perspective article, we compare leading theories of DG function. We note that these theories all critically rely on the generation of distinct patterns of activity in the region to signal differences between experiences and to reduce interference between memories. However, these theories are divided by the roles they attribute to the DG during learning and recall and by the contributions they ascribe to specific inputs or cell types within the DG. These differences influence the information that the DG is thought to impart to downstream structures. We work towards a holistic view of the role of DG in learning and memory by first developing three critical questions to foster a dialogue between the leading theories. We then evaluate the extent to which previous studies address our questions, highlight remaining areas of conflict, and suggest future experiments to bridge these theories.
Collapse
Affiliation(s)
- Mia Borzello
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA, USA
| | - Steve Ramirez
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, USA
| | | | - Inah Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Helen Scharfman
- Departments of Child and Adolescent Psychiatry, Neuroscience and Physiology and Psychiatry and the Neuroscience Institute, New York University Langone Health, New York, NY, USA
- The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Craig Stark
- Department of Neurobiology and Behaviour, University of California, Irvine, Irvine, CA, USA
| | - James J Knierim
- Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA
| | - Lara M Rangel
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA, USA.
| |
Collapse
|
10
|
Ravache TT, Batistuzzo A, Nunes GG, Gomez TGB, Lorena FB, Do Nascimento BPP, Bernardi MM, Lima ERR, Martins DO, Campos ACP, Pagano RL, Ribeiro MO. Multisensory Stimulation Reverses Memory Impairment in Adrβ 3KO Male Mice. Int J Mol Sci 2023; 24:10522. [PMID: 37445699 DOI: 10.3390/ijms241310522] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 07/15/2023] Open
Abstract
Norepinephrine plays an important role in modulating memory through its beta-adrenergic receptors (Adrβ: β1, β2 and β3). Here, we hypothesized that multisensory stimulation would reverse memory impairment caused by the inactivation of Adrβ3 (Adrβ3KO) with consequent inhibition of sustained glial-mediated inflammation. To test this, 21- and 86-day-old Adrβ3KO mice were exposed to an 8-week multisensory stimulation (MS) protocol that comprised gustatory and olfactory stimuli of positive and negative valence; intellectual challenges to reach food; the use of hidden objects; and the presentation of food in ways that prompted foraging, which was followed by analysis of GFAP, Iba-1 and EAAT2 protein expression in the hippocampus (HC) and amygdala (AMY). The MS protocol reduced GFAP and Iba-1 expression in the HC of young mice but not in older mice. While this protocol restored memory impairment when applied to Adrβ3KO animals immediately after weaning, it had no effect when applied to adult animals. In fact, we observed that aging worsened the memory of Adrβ3KO mice. In the AMY of Adrβ3KO older mice, we observed an increase in GFAP and EAAT2 expression when compared to wild-type (WT) mice that MS was unable to reduce. These results suggest that a richer and more diverse environment helps to correct memory impairment when applied immediately after weaning in Adrβ3KO animals and indicates that the control of neuroinflammation mediates this response.
Collapse
Affiliation(s)
- Thaís T Ravache
- Programa de Pós-Graduação em Distúrbios do Desenvolvimento, Centro de Ciências Biológicas e da Saúde Universidade Presbiteriana Mackenzie, São Paulo 01302-907, SP, Brazil
| | - Alice Batistuzzo
- Programa de Pós-Graduação em Distúrbios do Desenvolvimento, Centro de Ciências Biológicas e da Saúde Universidade Presbiteriana Mackenzie, São Paulo 01302-907, SP, Brazil
| | - Gabriela G Nunes
- Programa de Pós-Graduação em Distúrbios do Desenvolvimento, Centro de Ciências Biológicas e da Saúde Universidade Presbiteriana Mackenzie, São Paulo 01302-907, SP, Brazil
| | - Thiago G B Gomez
- Programa de Pós-Graduação em Distúrbios do Desenvolvimento, Centro de Ciências Biológicas e da Saúde Universidade Presbiteriana Mackenzie, São Paulo 01302-907, SP, Brazil
| | - Fernanda B Lorena
- Programa de Pós-Graduação em Distúrbios do Desenvolvimento, Centro de Ciências Biológicas e da Saúde Universidade Presbiteriana Mackenzie, São Paulo 01302-907, SP, Brazil
- Departamento de Medicina Translacional, Universidade Federal de São Paulo 04023-062, SP, Brazil
| | - Bruna P P Do Nascimento
- Programa de Pós-Graduação em Distúrbios do Desenvolvimento, Centro de Ciências Biológicas e da Saúde Universidade Presbiteriana Mackenzie, São Paulo 01302-907, SP, Brazil
- Departamento de Medicina Translacional, Universidade Federal de São Paulo 04023-062, SP, Brazil
| | - Maria Martha Bernardi
- Graduate Program in Environmental and Experimental Pathology, Paulista University, São Paulo 04026-002, SP, Brazil
| | - Eduarda R R Lima
- Laboratory of Neuroscience, Hospital Sírio-Libanês, São Paulo 01308-050, SP, Brazil
| | - Daniel O Martins
- Laboratory of Neuroscience, Hospital Sírio-Libanês, São Paulo 01308-050, SP, Brazil
| | - Ana Carolina P Campos
- Laboratory of Neuroscience, Hospital Sírio-Libanês, São Paulo 01308-050, SP, Brazil
- Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Rosana L Pagano
- Laboratory of Neuroscience, Hospital Sírio-Libanês, São Paulo 01308-050, SP, Brazil
| | - Miriam O Ribeiro
- Programa de Pós-Graduação em Distúrbios do Desenvolvimento, Centro de Ciências Biológicas e da Saúde Universidade Presbiteriana Mackenzie, São Paulo 01302-907, SP, Brazil
| |
Collapse
|
11
|
Wilmerding LK, Kondratyev I, Ramirez S, Hasselmo ME. Route-dependent spatial engram tagging in mouse dentate gyrus. Neurobiol Learn Mem 2023; 200:107738. [PMID: 36822466 PMCID: PMC10106405 DOI: 10.1016/j.nlm.2023.107738] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 01/30/2023] [Accepted: 02/16/2023] [Indexed: 02/23/2023]
Abstract
The dentate gyrus (DG) of hippocampus is hypothesized to act as a pattern separator that distinguishes between similar input patterns during memory formation and retrieval. Sparse ensembles of DG cells associated with learning and memory, i.e. engrams, have been labeled and manipulated to recall novel context memories. Functional studies of DG cell activity have demonstrated the spatial specificity and stability of DG cells during navigation. To reconcile how the DG contributes to separating global context as well as individual navigational routes, we trained mice to perform a delayed-non-match-to-position (DNMP) T-maze task and labeled DG neurons during performance of this task on a novel T-maze. The following day, mice navigated a second environment: the same T-maze, the same T-maze with one route permanently blocked but still visible, or a novel open field. We found that the degree of engram reactivation across days differed based on the traversal of maze routes, such that mice traversing only one arm had higher ensemble overlap than chance but less overlap than mice running the full two-route task. Mice experiencing the open field had similar ensemble sizes to the other groups but only chance-level ensemble reactivation. Ensemble overlap differences could not be explained by behavioral variability across groups, nor did behavioral metrics correlate to degree of ensemble reactivation. Together, these results support the hypothesis that DG contributes to spatial navigation memory and that partially non-overlapping ensembles encode different routes within the context of an environment.
Collapse
Affiliation(s)
- Lucius K Wilmerding
- Center for Systems Neuroscience, Boston University, United States; Graduate Program for Neuroscience, Boston University, United States; Department of Psychological and Brain Sciences, Boston University, United States.
| | - Ivan Kondratyev
- Center for Systems Neuroscience, Boston University, United States
| | - Steve Ramirez
- Center for Systems Neuroscience, Boston University, United States; Graduate Program for Neuroscience, Boston University, United States; Department of Psychological and Brain Sciences, Boston University, United States
| | - Michael E Hasselmo
- Center for Systems Neuroscience, Boston University, United States; Graduate Program for Neuroscience, Boston University, United States; Department of Psychological and Brain Sciences, Boston University, United States
| |
Collapse
|
12
|
Lorents A, Ruitenberg M, Schomaker J. Novelty-induced memory boosts in humans: The when and how. Heliyon 2023; 9:e14410. [PMID: 36942255 PMCID: PMC10023963 DOI: 10.1016/j.heliyon.2023.e14410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 02/24/2023] [Accepted: 03/03/2023] [Indexed: 03/10/2023] Open
Abstract
Novel information potentially signals danger or reward and behavioral and psychophysiological studies have suggested that the brain prioritizes its processing. Some effects of novelty even go beyond the stimulus itself. Studies in animals have robustly shown that exposure to novel stimulation can promote memory for information presented before or after this exposure. Research regarding effects of novelty on memory in humans is lagging, but in the last few years, several studies have emerged that suggest that memory-facilitating effects of novelty also exist in humans. Here, we provide a comprehensive overview of these studies. We identified several factors that have been shown to influence whether novelty promotes memory or not, including the timing between the novel experience and the learning events, the involvement with the novel material, and population characteristics (such as clinical diagnosis or age). Finally, we link the behavioral findings to potential neurobiological mechanisms and discuss the relevance of specific findings in light of potential clinical and educational applications that could leverage novelty to improve memory.
Collapse
Affiliation(s)
- A. Lorents
- Department of Health Medical and Neuropsychology, Institute of Psychology, Leiden University, the Netherlands
| | - M.F.L. Ruitenberg
- Department of Health Medical and Neuropsychology, Institute of Psychology, Leiden University, the Netherlands
- Leiden Institute for Brain and Cognition, the Netherlands
| | - J. Schomaker
- Department of Health Medical and Neuropsychology, Institute of Psychology, Leiden University, the Netherlands
- Leiden Institute for Brain and Cognition, the Netherlands
- Corresponding author. Department of Health Medical and Neuropsychology, Institute of Psychology, Leiden University, the Netherlands.
| |
Collapse
|
13
|
Quent JA, Henson RN. Novel immersive virtual reality experiences do not produce retroactive memory benefits for unrelated material. Q J Exp Psychol (Hove) 2022; 75:2197-2210. [PMID: 35135390 PMCID: PMC9619268 DOI: 10.1177/17470218221082491] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 12/17/2021] [Accepted: 01/10/2022] [Indexed: 11/17/2022]
Abstract
The experience of novelty can enhance memory for information that occurs close in time, even if not directly related to the experience-a phenomenon called "behavioural tagging." For example, an animal exposed to a novel spatial environment shows improved memory for other information presented previously. This has been linked to neurochemical modulations induced by novelty, which affect consolidation of memories for experiences that were encoded around the same time. Neurophysiological research in animals has shown that novelty benefits weakly encoded but not strongly encoded information. However, a benefit that is selective to weak memories seems difficult to reconcile with studies in humans that have reported that novelty improves recollection, but not familiarity. One possibility is that the novelty increases activity in hippocampus, which is also associated with processes that enable recollection. This is consistent with another prediction of behavioural tagging theory, namely that novelty only enhances consolidation of information that converges on the same neuronal population. However, no study has directly explored the relationship between encoding strength and retrieval quality (recollection versus familiarity). We examined the effects of exposure to a novel immersive virtual reality environment on memory for words presented immediately beforehand, under either deep or shallow encoding tasks, and by testing both recall memory immediately, and recognition memory with remember/know instructions the next day. However, Bayes factors showed no evidence to support the behavioural tagging predictions: that novelty would improve memory, particularly for shallowly encoded words, and this improvement would differentially affect familiarity versus recollection.
Collapse
Affiliation(s)
| | - Richard N Henson
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
- Department of Psychiatry, University of Cambridge, Cambridge, UK
| |
Collapse
|
14
|
Schomaker J, Baumann V, Ruitenberg MFL. Effects of exploring a novel environment on memory across the lifespan. Sci Rep 2022; 12:16631. [PMID: 36198743 PMCID: PMC9533976 DOI: 10.1038/s41598-022-20562-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 09/15/2022] [Indexed: 11/23/2022] Open
Abstract
Exploration of a novel environment has been shown to promote memory formation in healthy adults. Studies in animals have suggested that such novelty-induced memory boosts are mediated by hippocampal dopamine. The dopaminergic system is known to develop and deteriorate over the lifespan, but so far, the effects of novelty on memory across the lifespan have not yet been investigated. In the current study, we had children, adolescents, younger, and older adults (n = 439) explore novel and previously familiarized virtual environments to pinpoint the effects of spatial novelty on declarative memory in humans across different age groups. After exploration, words were presented while participants performed a deep or shallow encoding task. Incidental memory was quantified in a surprise test. Results showed that participants in the deep encoding condition remembered more words than those in the shallow condition, while novelty did not influence this effect. Interestingly, however, children, adolescents and younger adults benefitted from exploring a novel compared to a familiar environment as evidenced by better word recall, while these effects were absent in older adults. Our findings suggest that the beneficial effects of novelty on memory follow the deterioration of neural pathways involved in novelty-related processes across the lifespan.
Collapse
Affiliation(s)
- Judith Schomaker
- Department Health, Medical and Neuropsychology, Leiden University, Leiden, The Netherlands.
- Leiden Institute for Brain and Cognition, Leiden, The Netherlands.
| | - Valentin Baumann
- Department of Child and Adolescent Psychiatry and Psychotherapy, University of Magdeburg, Magdeburg, Germany
| | - Marit F L Ruitenberg
- Department Health, Medical and Neuropsychology, Leiden University, Leiden, The Netherlands
- Leiden Institute for Brain and Cognition, Leiden, The Netherlands
| |
Collapse
|
15
|
Maity S, Abbaspour R, Nahabedian D, Connor SA. Norepinephrine, beyond the Synapse: Coordinating Epigenetic Codes for Memory. Int J Mol Sci 2022; 23:ijms23179916. [PMID: 36077313 PMCID: PMC9456295 DOI: 10.3390/ijms23179916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 08/19/2022] [Accepted: 08/21/2022] [Indexed: 11/16/2022] Open
Abstract
The noradrenergic system is implicated in neuropathologies contributing to major disorders of the memory, including post-traumatic stress disorder and Alzheimer’s disease. Determining the impact of norepinephrine on cellular function and plasticity is thus essential for making inroads into our understanding of these brain conditions, while expanding our capacity for treating them. Norepinephrine is a neuromodulator within the mammalian central nervous system which plays important roles in cognition and associated synaptic plasticity. Specifically, norepinephrine regulates the formation of memory through the stimulation of β-ARs, increasing the dynamic range of synaptic modifiability. The mechanisms through which NE influences neural circuit function have been extended to the level of the epigenome. This review focuses on recent insights into how the noradrenergic recruitment of epigenetic modifications, including DNA methylation and post-translational modification of histones, contribute to homo- and heterosynaptic plasticity. These advances will be placed in the context of synaptic changes associated with memory formation and linked to brain disorders and neurotherapeutic applications.
Collapse
Affiliation(s)
- Sabyasachi Maity
- Department of Physiology, Neuroscience, and Behavioral Sciences, St. George’s University School of Medicine, True Blue FZ818, Grenada
| | - Raman Abbaspour
- Department of Biology, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - David Nahabedian
- The Center for Biomedical Visualization, Department of Anatomical Sciences, St. George’s University School of Medicine, True Blue FZ818, Grenada
| | - Steven A. Connor
- Department of Biology, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
- Correspondence: ; Tel.: +1-(416)-736-2100 (ext. 33803)
| |
Collapse
|
16
|
Reichardt R, Simor P, Polner B. Expectation of irrelevant novel stimuli has no consistent effect on recognition memory. Scand J Psychol 2022; 63:308-320. [PMID: 35390179 PMCID: PMC9542624 DOI: 10.1111/sjop.12807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 12/13/2021] [Accepted: 01/13/2022] [Indexed: 11/28/2022]
Abstract
Novelty is defined as the part of an experience that is not yet represented by memory systems. Novelty has been claimed to exert various memory-enhancing effects. A pioneering study by Wittmann et al. (2007) has shown that memory formation may even benefit from the expectation of novelty. We aimed to replicate this assumed memory effect in four behavioral studies. However, our results do not support the idea that anticipated novel stimuli are more memorable than unexpected novelty. In our experiments, we systematically manipulated the novelty predicting cues to ensure that the expectations were correctly formed by the participants, however, the results showed that there was no memory enhancement for expected novel pictures in any of the examined indices, thus we could not replicate the main behavioral finding of Wittmann et al. (2007). These results call into question the original effect, and we argue that this fits more into current thinking on memory formation and brain function in general. Our results are more consistent with the view that unexpected stimuli are more likely to be retained by memory systems. Predictive coding theory suggests that unexpected stimuli are prioritized by the nervous system and this may also benefit memory processes. Novel stimuli may be unexpected and thus recognized better in some experimental setups, yet novelty and unexpectedness do not always coincide. We hope that our work can bring more consistency in the literature on novelty, as educational methods in general could also benefit from this clarification.
Collapse
Affiliation(s)
- Richárd Reichardt
- Department of Cognitive Science, Budapest University of Technology and Economics, Budapest, Hungary
| | - Péter Simor
- Institute of Psychology, Eötvös Loránd University, Budapest, Hungary.,UR2NF, Neuropsychology and Functional Neuroimaging Research Unit at CRCN - Center for Research in Cognition and Neurosciences and UNI - ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium.,Institute of Behavioural Sciences, Semmelweis University, Budapest, Hungary
| | - Bertalan Polner
- Department of Cognitive Science, Budapest University of Technology and Economics, Budapest, Hungary
| |
Collapse
|
17
|
Survival of the salient: Aversive learning rescues otherwise forgettable memories via neural reactivation and post-encoding hippocampal connectivity. Neurobiol Learn Mem 2022; 187:107572. [PMID: 34871800 PMCID: PMC8755594 DOI: 10.1016/j.nlm.2021.107572] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 10/17/2021] [Accepted: 11/26/2021] [Indexed: 01/03/2023]
Abstract
The effects of aversive events on memory are complex and go beyond the simple enhancement of threatening information. Negative experiences can also rescue related but otherwise forgettable details encoded close in time. Here, we used functional magnetic resonance imaging (fMRI) in healthy young adults to examine the brain mechanisms that support this retrograde memory effect. In a two-phase incidental encoding paradigm, participants viewed different pictures of tools and animals before and during Pavlovian fear conditioning. During Phase 1, these images were intermixed with neutral scenes, which provided a unique 'context tag' for this specific phase of encoding. A few minutes later, during Phase 2, new pictures from one category were paired with a mild shock (threat-conditioned stimulus; CS+), while pictures from the other category were not shocked. FMRI analyses revealed that, across-participants, individuals who showed aversive learning-related retroactive memory benefits for Phase 1 CS+ items were also more likely to exhibit three brain effects: first, greater spontaneous reinstatement of the Phase 1 context when participants viewed conceptually-related CS+ items in Phase 2; second, greater successful encoding-related VTA/SN and LC activation for Phase 2 CS+ items; and third, learning-dependent increases in post-encoding hippocampal functional coupling with CS+ category-selective cortex. These biases in hippocampal-cortical connectivity also mediated the relationship between VTA/SN aversive encoding effects and across-participant variability in the retroactive memory benefit. Collectively, our findings suggest that both online and offline brain mechanisms may enable threatening events to preserve memories that acquire new significance in the future.
Collapse
|
18
|
McMorris T. The acute exercise-cognition interaction: From the catecholamines hypothesis to an interoception model. Int J Psychophysiol 2021; 170:75-88. [PMID: 34666105 DOI: 10.1016/j.ijpsycho.2021.10.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 09/06/2021] [Accepted: 10/11/2021] [Indexed: 02/08/2023]
Abstract
An interoception model for the acute exercise-cognition interaction is presented. During exercise following the norepinephrine threshold, interoceptive feedback induces increased tonic release of extracellular catecholamines, facilitating phasic release hence better cognitive performance of executive functions. When exercise intensity increases to maximum, the nature of task-induced norepinephrine release from the locus coeruleus is dependent on interaction between motivation, perceived effort costs and perceived availability of resources. This is controlled by interaction between the rostral and dorsolateral prefrontal cortices, orbitofrontal cortex, anterior cingulate cortex and anterior insula cortex. If perceived available resources are sufficient to meet predicted effort costs and reward value is high, tonic release from the locus coeruleus is attenuated thus facilitating phasic release, therefore cognition is not inhibited. However, if perceived available resources are insufficient to meet predicted effort costs or reward value is low, tonic release from the locus coeruleus is induced, attenuating phasic release. As a result, cognition is inhibited, although long-term memory and tasks that require switching to new stimuli-response couplings are probably facilitated.
Collapse
Affiliation(s)
- Terry McMorris
- Institute of Sport, University of Chichester, College Lane, Chichester, West Sussex PO19 6PE, United Kingdom; Department of Sport and Exercise Science, Faculty of Science, University of Portsmouth, Guildhall Walk, Portsmouth PO1 2ER, United Kingdom.
| |
Collapse
|
19
|
Grella SL, Gomes SM, Lackie RE, Renda B, Marrone DF. Norepinephrine as a spatial memory reset signal. Behav Pharmacol 2021; 32:531-548. [PMID: 34417358 DOI: 10.1097/fbp.0000000000000648] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Contextual information is represented in the hippocampus (HPC) partially through the recruitment of distinct neuronal ensembles. It is believed that reactivation of these ensembles underlies memory retrieval processes. Recently, we showed that norepinephrine input from phasic locus coeruleus activation induces hippocampal plasticity resulting in the recruitment of new neurons and disengagement from previously established representations. We hypothesize that norepinephrine may provide a neuromodulatory mnemonic switch signaling the HPC to move from a state of retrieval to encoding in the presence of novelty, and therefore, plays a role in memory updating. Here, we tested whether bilateral dorsal dentate gyrus (dDG) infusions of the β-adrenergic receptor (BAR) agonist isoproterenol (ISO), administered prior to encoding or retrieval, would impair spatial working and reference memory by reverting, the system to encoding (thereby recruiting new neurons) potentially interfering with the retrieval of the previously established spatial ensemble. We also investigated whether dDG infusions of ISO could promote cognitive flexibility by switching the system to encoding when it is adaptive (ie, when new information is presented, eg, reversal learning). We found that intra-dDG infusions of ISO given prior to retrieval caused deficits in working and reference memory which was blocked by pretreatment with the BAR-antagonist, propranolol (PRO). In contrast, ISO administered prior to reversal learning led to improved performance. These data support our hypothesis that norepinephrine serves as a novelty signal to update HPC contextual representations via BAR activation-facilitated recruitment of new neurons. This can be both maladaptive and adaptive depending on the situation.
Collapse
Affiliation(s)
- Stephanie L Grella
- Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada
- Department of Psychological & Brain Sciences, Boston University, Boston, Massachusetts, USA
| | - Sarah M Gomes
- Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada
- Faculty of Health Sciences, School of Medicine, Queen's University, Kingston
| | - Rachel E Lackie
- Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada
- Program in Neuroscience, Robarts Research Institute, University of Western Ontario, London
| | - Briana Renda
- Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada
- Department of Psychology, University of Guelph, Guelph, Ontario, Canada
| | - Diano F Marrone
- Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada
- McKnight Brain Institute, University of Arizona, Tucson, Arizona, USA
| |
Collapse
|
20
|
Quent JA, Henson RN, Greve A. A predictive account of how novelty influences declarative memory. Neurobiol Learn Mem 2021; 179:107382. [PMID: 33476747 PMCID: PMC8024513 DOI: 10.1016/j.nlm.2021.107382] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 11/08/2020] [Accepted: 01/10/2021] [Indexed: 01/13/2023]
Abstract
A rich body of studies in the human and non-human literature has examined the question how novelty influences memory. For a variety of different stimuli, ranging from simple objects and words to vastly complex scenarios, the literature reports that novelty improves memory in some cases, but impairs memory in other cases. In recent attempts to reconcile these conflicting findings, novelty has been divided into different subtypes, such as relative versus absolute novelty, or stimulus versus contextual novelty. Nevertheless, a single overarching theory of novelty and memory has been difficult to attain, probably due to the complexities in the interactions among stimuli, environmental factors (e.g., spatial and temporal context) and level of prior knowledge (but see Duszkiewicz et al., 2019; Kafkas & Montaldi, 2018b; Schomaker & Meeter, 2015). Here we describe how a predictive coding framework might be able to shed new light on different types of novelty and how they affect declarative memory in humans. More precisely, we consider how prior expectations modulate the influence of novelty on encoding episodes into memory, e.g., in terms of surprise, and how novelty/surprise affect memory for surrounding information. By reviewing a range of behavioural findings and their possible underlying neurobiological mechanisms, we highlight where a predictive coding framework succeeds and where it appears to struggle.
Collapse
Affiliation(s)
| | - Richard N Henson
- MRC Cognition and Brain Sciences Unit, University of Cambridge, United Kingdom; Department of Psychiatry, University of Cambridge, United Kingdom
| | - Andrea Greve
- MRC Cognition and Brain Sciences Unit, University of Cambridge, United Kingdom
| |
Collapse
|
21
|
Baumann V, Birnbaum T, Breitling-Ziegler C, Tegelbeckers J, Dambacher J, Edelmann E, Bergado-Acosta JR, Flechtner HH, Krauel K. Exploration of a novel virtual environment improves memory consolidation in ADHD. Sci Rep 2020; 10:21453. [PMID: 33293595 PMCID: PMC7722922 DOI: 10.1038/s41598-020-78222-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 11/19/2020] [Indexed: 01/09/2023] Open
Abstract
Experimental evidence in rodents and humans suggests that long-term memory consolidation can be enhanced by the exploration of a novel environment presented during a vulnerable early phase of consolidation. This memory enhancing effect (behavioral tagging) is caused by dopaminergic and noradrenergic neuromodulation of hippocampal plasticity processes. In translation from animal to human research, we investigated whether behavioral tagging with novelty can be used to tackle memory problems observed in children and adolescents with attention-deficit/hyperactivity disorder (ADHD). 34 patients with ADHD and 34 typically developing participants (age 9–15 years) explored either a previously familiarized or a novel virtual environment 45 min after they had learned a list of 20 words. Participants took a free recall test both immediately after learning the word list and after 24 h. Patients who explored a familiar environment showed significantly impaired memory consolidation compared to typically developing peers. Exploration of a novel environment led to significantly better memory consolidation in children and adolescents with ADHD. However, we did not observe a beneficial effect of novel environment exploration in typically developing participants. Our data rather suggested that increased exploration of a novel environment as well as higher feelings of virtual immersion compromised memory performance in typically developing children and adolescents, which was not the case for patients with ADHD. We propose that behavioral tagging with novel virtual environments is a promising candidate to overcome ADHD related memory problems. Moreover, the discrepancy between children and adolescents with and without ADHD suggests that behavioral tagging might only be able to improve memory consolidation for weakly encoded information.
Collapse
Affiliation(s)
- Valentin Baumann
- Department of Child and Adolescent Psychiatry and Psychotherapy, University of Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany.
| | - Thomas Birnbaum
- Department of Child and Adolescent Psychiatry and Psychotherapy, University of Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany
| | - Carolin Breitling-Ziegler
- Department of Child and Adolescent Psychiatry and Psychotherapy, University of Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany
| | - Jana Tegelbeckers
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Johannes Dambacher
- Department of Child and Adolescent Psychiatry and Psychotherapy, University of Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany.,Faculty of Computer Science, University of Magdeburg, Magdeburg, Germany
| | - Elke Edelmann
- Department of Physiology, University of Kiel, Kiel, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Jorge R Bergado-Acosta
- Department of Pharmacology and Toxicology, University of Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Hans-Henning Flechtner
- Department of Child and Adolescent Psychiatry and Psychotherapy, University of Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany
| | - Kerstin Krauel
- Department of Child and Adolescent Psychiatry and Psychotherapy, University of Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| |
Collapse
|
22
|
Nguyen PV, Connor SA. Noradrenergic Regulation of Hippocampus-Dependent Memory. Cent Nerv Syst Agents Med Chem 2020; 19:187-196. [PMID: 31749419 DOI: 10.2174/1871524919666190719163632] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/24/2019] [Accepted: 06/28/2019] [Indexed: 12/24/2022]
Abstract
Neuromodulation regulates critical functions of CNS synapses, ranging from neural circuit development to high-order cognitive processes, including learning and memory. This broad scope of action is generally mediated through alterations of the strength of synaptic transmission (i.e. synaptic plasticity). Changes in synaptic strength are widely considered to be a cellular representation of learned information. Noradrenaline is a neuromodulator that is secreted throughout the brain in response to novelty or increased arousal. Once released, noradrenaline activates metabotropic receptors, initiating intracellular signaling cascades that promote enduring changes in synaptic strength and facilitate memory storage. Here, we provide an overview of noradrenergic modulation of synaptic plasticity and memory formation within mammalian neural circuits, which has broad applicability within the neurotherapeutics community. Advances in our understanding of noradrenaline in the context of these processes may provide a foundation for refining treatment strategies for multiple brain diseases, ranging from post-traumatic stress disorder to Alzheimer's Disease.
Collapse
Affiliation(s)
- Peter V Nguyen
- Department of Physiology, University of Alberta School of Medicine, Edmonton, AB, T6G 2H7, Canada
| | - Steven A Connor
- Department of Biology, York University, 4700 Keele Street, Toronto, ON, M3J 1P3, Canada
| |
Collapse
|
23
|
Ranjbar-Slamloo Y, Fazlali Z. Dopamine and Noradrenaline in the Brain; Overlapping or Dissociate Functions? Front Mol Neurosci 2020; 12:334. [PMID: 32038164 PMCID: PMC6986277 DOI: 10.3389/fnmol.2019.00334] [Citation(s) in RCA: 98] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 12/27/2019] [Indexed: 12/21/2022] Open
Abstract
Dopamine and noradrenaline are crucial neuromodulators controlling brain states, vigilance, action, reward, learning, and memory processes. Ventral tegmental area (VTA) and Locus Coeruleus (LC) are canonically described as the main sources of dopamine (DA) and noradrenaline (NA) with dissociate functions. A comparison of diverse studies shows that these neuromodulators largely overlap in multiple domains such as shared biosynthetic pathway and co-release from the LC terminals, convergent innervations, non-specificity of receptors and transporters, and shared intracellular signaling pathways. DA–NA interactions are mainly studied in prefrontal cortex and hippocampus, yet it can be extended to the whole brain given the diversity of catecholamine innervations. LC can simultaneously broadcast both dopamine and noradrenaline across the brain. Here, we briefly review the molecular, cellular, and physiological overlaps between DA and NA systems and point to their functional implications. We suggest that DA and NA may function in parallel to facilitate learning and maintain the states required for normal cognitive processes. Various signaling modules of NA and DA have been targeted for developing of therapeutics. Understanding overlaps of the two systems is crucial for more effective interventions in a range of neuropsychiatric conditions.
Collapse
Affiliation(s)
- Yadollah Ranjbar-Slamloo
- Eccles Institute of Neuroscience, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - Zeinab Fazlali
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
| |
Collapse
|
24
|
Facilitation of fear extinction by novelty is modulated by β-adrenergic and 5-HT1A serotoninergic receptors in hippocampus. Neurobiol Learn Mem 2019; 166:107101. [DOI: 10.1016/j.nlm.2019.107101] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 08/21/2019] [Accepted: 10/16/2019] [Indexed: 01/15/2023]
|
25
|
Biel D, Bunzeck N. Novelty Before or After Word Learning Does Not Affect Subsequent Memory Performance. Front Psychol 2019; 10:1379. [PMID: 31316414 PMCID: PMC6610293 DOI: 10.3389/fpsyg.2019.01379] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 05/28/2019] [Indexed: 01/10/2023] Open
Abstract
In humans, exposure to novel images and exploration of novel virtual environments before the encoding of words improved subsequent memory performance. Animal studies revealed similar effects of novelty, both before and after learning, and could show that hippocampus-dependent dopaminergic neuromodulation plays an important role. Here, we further investigated the effects of novelty on long-term memory in humans using a novel paradigm employing short sequences of nature movies presented either before or at two time points after learning of unrelated words. Since novelty processing is associated with a release of dopamine into the hippocampus, we hypothesized that novelty exposure primarily affects hippocampus-dependent memory (i.e., recollection) but not hippocampus-independent memory (i.e., familiarity). We tested 182 healthy human subjects in three experiments including a word-learning task followed by a 1-day delayed recognition task. Importantly, participants were exposed to novel (NOV) or familiar movies (FAM) at three time points: (experiment 1) directly after encoding of the word list, (experiment 2) 15 min after encoding, (experiment 3) 15 min prior to encoding. As expected, novel movies were perceived as more interesting and led to better mood. During word recognition, reaction times were faster for remember as compared to familiarity responses in all three experiments, but this effect was not modulated by novelty. In contrast to our main hypothesis, there was no effect of novelty – before or after encoding – on subsequent word recognition, including recollection and familiarity scores. Therefore, an exposure to novel movies without an active task does not affect hippocampus-dependent and hippocampus-independent long-term recognition memory for words in humans.
Collapse
Affiliation(s)
- Davina Biel
- Institute of Psychology I, University of Lübeck, Lübeck, Germany
| | - Nico Bunzeck
- Institute of Psychology I, University of Lübeck, Lübeck, Germany
| |
Collapse
|
26
|
Brandwein NJ, Nguyen PV. A requirement for epigenetic modifications during noradrenergic stabilization of heterosynaptic LTP in the hippocampus. Neurobiol Learn Mem 2019; 161:72-82. [PMID: 30930287 DOI: 10.1016/j.nlm.2019.03.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 03/22/2019] [Accepted: 03/27/2019] [Indexed: 12/31/2022]
Abstract
Beta-adrenergic receptor (b-AR) activation by noradrenaline (NA) enhances memory formation and long-term potentiation (LTP), a form of synaptic plasticity characterized by an activity-dependent increase in synaptic strength. LTP is believed to be a cellular mechanism for contextual learning and memory. In the mammalian hippocampus, LTP can be observed at multiple synaptic pathways after strong stimulation of a single synaptic pathway. This heterosynaptic LTP is believed to involve synaptic tagging of active synapses and capture of plasticity-related proteins that enable heterosynaptic transfer of persistent potentiation. These processes may permit distinct neural pathways to associate information transmitted by separate, but convergent, synaptic inputs. We had previously shown that transcription and epigenetic modifications were necessary for stabilization of homosynaptic LTP. However, it is unclear whether transfer of LTP to a second, heterosynaptic pathway involves b-ARs signalling to the nucleus. Using electrophysiologic recordings in area CA1 of murine hippocampal slices, we show here that pharmacologically inhibiting b-AR activation, transcription, DNA methyltransferase or histone acetyltransferase activation, prevents stabilization of heterosynaptic LTP. Our data suggest that noradrenergic stabilization of heterosynaptic ("tagged") LTP requires not only transcription, but specifically, DNA methylation and histone acetylation. NA promotes stable heterosynaptic plasticity through engagement of nuclear processes that may contribute to prompt consolidation of short-term memories into resilient long-term memories under conditions when the brain's noradrenergic system is recruited.
Collapse
Affiliation(s)
- N J Brandwein
- Department of Physiology, University of Alberta School of Medicine, Edmonton, Alberta T6G 2H7, Canada
| | - P V Nguyen
- Department of Physiology, University of Alberta School of Medicine, Edmonton, Alberta T6G 2H7, Canada.
| |
Collapse
|
27
|
Schomaker J. Unexplored territory: Beneficial effects of novelty on memory. Neurobiol Learn Mem 2019; 161:46-50. [PMID: 30862524 DOI: 10.1016/j.nlm.2019.03.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 03/07/2019] [Accepted: 03/08/2019] [Indexed: 01/17/2023]
Abstract
Exploring novel environments enhances learning in animals. Due to differing traditions, research into the effects of spatial novelty on learning in humans is scarce. Recent developments of affordable and fMRI-compatible virtual reality (VR) and mobile EEG systems can help bridge the gap between the two literatures. One promising study showed that spatial novelty also promotes learning in humans. It still remains largely unknown, however, which aspect of novelty underlies the beneficial effect on memory, as novelty, expectations, and volition are often confounded in animal studies. In humans, these factors can be experimentally manipulated, but such studies are currently lacking. Future studies in humans could combine pharmacological interventions, neuroimaging and VR or use mobile EEG to help elucidate whether the plasticity enhancing mechanisms observed in animals, also exist in humans. When the aspects of exploring a novel environment underlying beneficial memory effects have been identified, effective novelty-exposure interventions could be designed to improve learning and counteract age-related memory decline.
Collapse
Affiliation(s)
- J Schomaker
- Section Health, Medical and Neuropsychology, Institute of Psychology, Leiden University, Leiden, the Netherlands.
| |
Collapse
|
28
|
A theory of general intelligence. Med Hypotheses 2019; 123:35-46. [PMID: 30696589 DOI: 10.1016/j.mehy.2018.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 12/01/2018] [Indexed: 11/20/2022]
Abstract
This paper proposes a theoretical framework for the biological learning mechanism as a general learning system. The proposal is as follows. The bursting and tonic modes of firing patterns found in many neuron types in the brain correspond to two separate modes of information processing, with one mode resulting in awareness, and another mode being subliminal. In such a coding scheme, a neuron in bursting state codes for the highest level of perceptual abstraction representing a pattern of sensory stimuli, or volitional abstraction representing a pattern of muscle contraction sequences. Within the 50-250 ms minimum integration time of experience, the bursting neurons form synchrony ensembles to allow for binding of related percepts. The degree which different bursting neurons can be merged into the same synchrony ensemble depends on the underlying cortical connections that represent the degree of perceptual similarity. These synchrony ensembles compete for selective attention to remain active. The dominant synchrony ensemble triggers episodic memory recall in the hippocampus, while forming new episodic memory with current sensory stimuli, resulting in a stream of thoughts. Neuromodulation modulates both top-down selection of synchrony ensembles, and memory formation. Episodic memory stored in the hippocampus is transferred to semantic and procedural memory in the cortex during rapid eye movement sleep, by updating cortical neuron synaptic weights with spike timing dependent plasticity. With the update of synaptic weights, new neurons become bursting while previous bursting neurons become tonic, allowing bursting neurons to move up to a higher level of perceptual abstraction. Finally, the proposed learning mechanism is compared with the back-propagation algorithm used in deep neural networks, and a proposal of how the credit assignment problem can be addressed by the current theory is presented.
Collapse
|
29
|
Brandwein NJ, Nguyen PV. Noradrenergic stabilization of heterosynaptic LTP requires activation of Epac in the hippocampus. ACTA ACUST UNITED AC 2019; 26:31-38. [PMID: 30651375 PMCID: PMC6340117 DOI: 10.1101/lm.048660.118] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 11/30/2018] [Indexed: 01/05/2023]
Abstract
Beta-adrenergic receptor (β-AR) activation by norepinephrine (NE) enhances memory and stabilizes long-term potentiation (LTP), a form of synaptic plasticity believed to underlie some forms of hippocampal memory. LTP can occur at multiple synaptic pathways as a result of strong stimulation to one pathway preceding milder stimulation of an adjacent, independent pathway. Synaptic tagging allows LTP to be transferred, or captured, at heterosynaptic pathways. Previous research has shown that β-AR activation promotes heterosynaptic LTP by engaging various signaling cascades. In particular, cyclic adenosine monophosphate (cAMP) activates cAMP-dependent protein kinase A (PKA) and guanine nucleotide exchange protein activated by cAMP (Epac), to enhance LTP. Epac activation can occlude subsequent induction of stable homosynaptic LTP after β-AR activation, but it is unclear whether Epac activation is required for heterosynaptic LTP following pairing of the natural transmitter, NE, with one 100 Hz train of stimulation ("NE-LTP"). Using electrophysiologic recordings of CA1 field excitatory postsynaptic potentials during stimulation of two independent synaptic pathways in murine hippocampal slices, we show that distinct inhibitors of Epac blocked stabilization of homo- and heterosynaptic NE-LTP. PKA inhibition also attenuated heterosynaptic transfer of NE-LTP, but only when a PKA inhibitor was applied during tetanization of a second, heterosynaptic pathway that was not treated with NE. Our data suggest that NE, paired with 100 Hz, activates Epac to stabilize homo- and heterosynaptic LTP. Epac may regulate the production of plasticity-related proteins and subsequent synaptic capture of NE-LTP at a heterosynaptic pathway. Epac activation under these conditions may enable behavioral experiences that engage noradrenergic inputs to hippocampal circuits to be transformed into stable long-term memories.
Collapse
Affiliation(s)
- Nathan J Brandwein
- Department of Physiology and Institute of Neuroscience and Mental Health, University of Alberta School of Medicine, Edmonton, Alberta T6G 2H7, Canada
| | - Peter V Nguyen
- Department of Physiology and Institute of Neuroscience and Mental Health, University of Alberta School of Medicine, Edmonton, Alberta T6G 2H7, Canada
| |
Collapse
|
30
|
Gharib A, Sayyahi Z, Komaki A, Barkley V, Sarihi A, Mirnajafi-Zadeh J. The role of 5-HT 1A receptors of hippocampal CA1 region in anticonvulsant effects of low-frequency stimulation in amygdala kindled rats. Physiol Behav 2018; 196:119-125. [PMID: 30179595 DOI: 10.1016/j.physbeh.2018.08.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/31/2018] [Accepted: 08/31/2018] [Indexed: 01/24/2023]
Abstract
Low frequency stimulation (LFS) has been proposed as a method in the treatment of epilepsy, but its anticonvulsant mechanism is still unknown. In the current study, the hippocampal CA1 region was microinjected with NAD-299 (a selective 5-HT1A antagonist), and its role in mediating the inhibitory action of LFS on amygdala kindling was investigated. Male Wistar rats were kindled by amygdala stimulation in a semi-rapid kindling manner (12 stimulations per day). LFS (0.1 ms pulse duration at 1 Hz, 200 pulses, 50-150 μA) was applied at 5 min after termination of daily kindling stimulations. NAD (a selective 5-HT1A antagonist) was microinjected into the CA1 region of the hippocampus at the doses of 2.5 and 5 μg/1 μl. An open field test was also run to determine the motor activity of animals in different experimental groups. The application of LFS following daily kindling stimulations reduced the behavioral seizure stages, afterdischarge duration, and stage 5 seizure duration and increased the latency to stage 4 seizure compared to the kindled group. However, microinjection of NAD at the doses of 5 μg/1 μl, but not 2.5 μg/1 μl, blocked the inhibitory effect of LFS on behavioral and electrophysiological parameters in kindled animals. It could be presumed that 5-HT1A receptors in the CA1 area are involved in mediating the antiepileptic effects of LFS.
Collapse
Affiliation(s)
- Alireza Gharib
- Department of Physiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Zeinab Sayyahi
- Department of Physiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Alireza Komaki
- Department of Physiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Victoria Barkley
- Krembil Research Institute, University Health Network, Toronto, Canada
| | - Abdolrahman Sarihi
- Department of Physiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| |
Collapse
|
31
|
Adrenergic β receptor activation in the basolateral amygdala, which is intracellular Zn 2+-dependent, rescues amyloid β 1-42-induced attenuation of dentate gyrus LTP. Neurochem Int 2018; 120:43-48. [PMID: 30030113 DOI: 10.1016/j.neuint.2018.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 06/27/2018] [Accepted: 07/16/2018] [Indexed: 01/01/2023]
Abstract
On the basis of the evidence that the basolateral amygdala (BLA) modulates hippocampal memory processes via synaptic plasticity, here we report that adrenergic β receptor activation in the BLA rescues amyloid β1-42 (Aβ1-42)-induced attenuation of long-term potentiation (LTP) at perforant pathway-dentate granule cell (DGC) synapses. When 500 μM isoproterenol (2 μl), an adrenergic β receptor agonist, was injected into the BLA 20 min before LTP induction, LTP was enhanced. Isoproterenol-mediated enhancement of LTP was blocked by co-injection with 100 μM ZnAF-2DA, an intracellular Zn2+ chelator, suggesting that intracellular Zn2+ is required for the intracellular signaling cascade after adrenergic β receptor activation in the BLA. Aβ1-42-induced attenuation of LTP, which was induced by Aβ1-42 injection into the dentate gyrus 60 min before LTP induction, was rescued by isoproterenol injection into the BLA 20 min before LTP induction, but not by 500 μM phenylephrine (2 μl), an adrenergic α1 receptor agonist, injection into the BLA, which did not enhance LTP unlike the case of isoproterenol injection. Interestingly, Aβ1-42-induced attenuation of LTP was also rescued by 100 μM isoproterenol injection into the BLA 20 min before LTP induction, which did not enhance LTP. The present study demonstrates that adrenergic β receptor activation in the BLA, which is linked with intracellular Zn2+ signaling, rescues Aβ1-42-induced attenuation of dentate gyrus LTP. It is likely that adrenergic β receptor activation in the BLA is a strategy for rescuing Aβ1-42-induced cognitive decline that is associated with hippocampal synaptic plasticity.
Collapse
|
32
|
β-adrenergic receptors reduce the threshold for induction and stabilization of LTP and enhance its magnitude via multiple mechanisms in the ventral but not the dorsal hippocampus. Neurobiol Learn Mem 2018; 151:71-84. [PMID: 29653257 DOI: 10.1016/j.nlm.2018.04.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 03/19/2018] [Accepted: 04/07/2018] [Indexed: 12/27/2022]
Abstract
The hippocampus is a functionally heterogeneous structure with the cognitive and emotional signal processing ascribed to the dorsal (DH) and the ventral hippocampus (VH) respectively. However, the underlying mechanisms are poorly understood. Noradrenaline is released in hippocampus during emotional arousal modulating synaptic plasticity and memory consolidation through activation of β adrenergic receptors (β-ARs). Using recordings of field excitatory postsynaptic potentials from the CA1 field of adult rat hippocampal slices we demonstrate that long-term potentiation (LTP) induced either by theta-burst stimulation (TBS) that mimics a physiological firing pattern of hippocampal neurons or by high-frequency stimulation is remarkably more sensitive to β-AR activation in VH than in DH. Thus, pairing of subthreshold primed burst stimulation with activation of β-ARs by their agonist isoproterenol (1 μM) resulted in a reliable induction of NMDA receptor-dependent LTP in the VH without affecting LTP in the DH. Activation of β-ARs by isoproterenol during application of intense TBS increased the magnitude of LTP in both hippocampal segments but facilitated voltage-gated calcium channel-dependent LTP in VH only. Endogenous β-AR activation contributed to the stabilization and the magnitude of LTP in VH but not DH as demonstrated by the effects of the β-ARs antagonist propranolol (10 μM). Exogenous (but not endogenous) β-AR activation strongly increased TBS-induced facilitation of postsynaptic excitability in VH. In DH, isoproterenol only produced a moderate and GABAergic inhibition-dependent enhancement in the facilitation of synaptic burst responses. Paired-pulse facilitation did not change with LTP at any experimental condition suggesting that expression of LTP does not involve presynaptic mechanisms. These findings suggest that β-AR may act as a switch that selectively promotes synaptic plasticity in VH through multiple ways and provide thus a first clue to mechanisms that underlie VH involvement in emotionality.
Collapse
|
33
|
Chesworth R, Corbit LH. Noradrenergic β-receptor antagonism in the basolateral amygdala impairs reconsolidation, but not extinction, of alcohol self-administration: Intra-BLA propranolol impairs reconsolidation of alcohol self-administration. Neurobiol Learn Mem 2018; 151:59-70. [PMID: 29649583 DOI: 10.1016/j.nlm.2018.04.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 03/19/2018] [Accepted: 04/06/2018] [Indexed: 11/26/2022]
Abstract
A critical barrier to recovery from alcohol addiction is relapse propensity. Alcohol cues can trigger relapse, and pharmacologically facilitating processes such as extinction, which decreases cue associations, may help prevent relapse. The noradrenergic system mediates extinction learning for alcohol; however, the neural locus of this effect is unknown. This study sought to determine whether the basolateral amygdala (BLA), a region critical for fear extinction, also mediates extinction of alcohol seeking. Hooded Wistar rats (N = 12-15 per experiment) were implanted with bilateral cannula targeting the BLA and trained to lever press for 10% ethanol during auditory or visual cues. Infusions of the β-receptor antagonist propranolol (2 µg/side) were administered prior to extinction (Experiment 1), and rats assessed for relapse-like behaviour two weeks later, thus allowing for spontaneous recovery. We expected intra-BLA propranolol to impair extinction learning; however, propranolol-treated rats exhibited reduced responding in the test of spontaneous recovery, suggesting enhanced extinction. We investigated this unexpected result by determining if propranolol treatment affected memory processes other than extinction. In a subsequent experiment, rats were infused with propranolol immediately after extinction to target consolidation of extinction (Experiment 2a), and assessed for spontaneous recovery. Propranolol was also infused after self-administration to target reconsolidation of the original learning (Experiment 2b). Propranolol treatment had no effect on consolidation of extinction learning, but impaired reconsolidation of self-administration. Propranolol administered prior to a self-administration session did not affect reinforced responding (Experiment 2c). Extinction and reconsolidation are opposing processes triggered by specific test conditions. We suggest our test conditions induced reconsolidation of self-administration memory by propranolol, rather than modulation of extinction. Thus, our data implicates intra-BLA noradrenergic β-receptors in reconsolidation of alcohol self-administration memory.
Collapse
|
34
|
Curiosity in old age: A possible key to achieving adaptive aging. Neurosci Biobehav Rev 2018; 88:106-116. [PMID: 29545165 DOI: 10.1016/j.neubiorev.2018.03.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 01/11/2018] [Accepted: 03/07/2018] [Indexed: 02/08/2023]
Abstract
Curiosity is a fundamental part of human motivation that supports a variety of human intellectual behaviors ranging from early learning in children to scientific discovery. However, there has been little attention paid to the role of curiosity in aging populations. By bringing together broad but sparse neuroscientific and psychological literature on curiosity and related concepts (e.g., novelty seeking in older adults), we propose that curiosity, although it declines with age, plays an important role in maintaining cognitive function, mental health, and physical health in older adults. We identify the dopaminergic reward system and the noradrenergic system as the key brain systems implicated in curiosity processing and discuss how these brain systems contribute to the relationship between curiosity and adaptive aging.
Collapse
|
35
|
Gönner L, Vitay J, Hamker FH. Predictive Place-Cell Sequences for Goal-Finding Emerge from Goal Memory and the Cognitive Map: A Computational Model. Front Comput Neurosci 2017; 11:84. [PMID: 29075187 PMCID: PMC5643423 DOI: 10.3389/fncom.2017.00084] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 09/01/2017] [Indexed: 01/19/2023] Open
Abstract
Hippocampal place-cell sequences observed during awake immobility often represent previous experience, suggesting a role in memory processes. However, recent reports of goals being overrepresented in sequential activity suggest a role in short-term planning, although a detailed understanding of the origins of hippocampal sequential activity and of its functional role is still lacking. In particular, it is unknown which mechanism could support efficient planning by generating place-cell sequences biased toward known goal locations, in an adaptive and constructive fashion. To address these questions, we propose a model of spatial learning and sequence generation as interdependent processes, integrating cortical contextual coding, synaptic plasticity and neuromodulatory mechanisms into a map-based approach. Following goal learning, sequential activity emerges from continuous attractor network dynamics biased by goal memory inputs. We apply Bayesian decoding on the resulting spike trains, allowing a direct comparison with experimental data. Simulations show that this model (1) explains the generation of never-experienced sequence trajectories in familiar environments, without requiring virtual self-motion signals, (2) accounts for the bias in place-cell sequences toward goal locations, (3) highlights their utility in flexible route planning, and (4) provides specific testable predictions.
Collapse
Affiliation(s)
- Lorenz Gönner
- Artificial Intelligence, Department of Computer Science, Technische Universität Chemnitz, Chemnitz, Germany
| | - Julien Vitay
- Artificial Intelligence, Department of Computer Science, Technische Universität Chemnitz, Chemnitz, Germany
| | - Fred H Hamker
- Artificial Intelligence, Department of Computer Science, Technische Universität Chemnitz, Chemnitz, Germany.,Bernstein Center Computational Neuroscience, Humboldt-Universität Berlin, Berlin, Germany
| |
Collapse
|
36
|
Developing the catecholamines hypothesis for the acute exercise-cognition interaction in humans: Lessons from animal studies. Physiol Behav 2016; 165:291-9. [DOI: 10.1016/j.physbeh.2016.08.011] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 08/08/2016] [Accepted: 08/09/2016] [Indexed: 12/16/2022]
|
37
|
Yang K, Broussard JI, Levine AT, Jenson D, Arenkiel BR, Dani JA. Dopamine receptor activity participates in hippocampal synaptic plasticity associated with novel object recognition. Eur J Neurosci 2016; 45:138-146. [PMID: 27646422 DOI: 10.1111/ejn.13406] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 09/14/2016] [Accepted: 09/16/2016] [Indexed: 01/24/2023]
Abstract
Physiological and behavioral evidence supports that dopamine (DA) receptor signaling influences hippocampal function. While several recent studies examined how DA influences CA1 plasticity and learning, there are fewer studies investigating the influence of DA signaling to the dentate gyrus. The dentate gyrus receives convergent cortical input through the perforant path fiber tracts and has been conceptualized to detect novelty in spatial memory tasks. To test whether DA-receptor activity influences novelty-detection, we used a novel object recognition (NOR) task where mice remember previously presented objects as an indication of learning. Although DA innervation arises from other sources and the main DA signaling may be from those sources, our molecular approaches verified that midbrain dopaminergic fibers also sparsely innervate the dentate gyrus. During the NOR task, wild-type mice spent significantly more time investigating novel objects rather than previously observed objects. Dentate granule cells in slices cut from those mice showed an increased AMPA/NMDA-receptor current ratio indicative of potentiated synaptic transmission. Post-training injection of a D1-like receptor antagonist not only effectively blocked the preference for the novel objects, but also prevented the increased AMPA/NMDA ratio. Consistent with that finding, neither NOR learning nor the increase in the AMPA/NMDA ratio were observed in DA-receptor KO mice under the same experimental conditions. The results indicate that DA-receptor signaling contributes to the successful completion of the NOR task and to the associated synaptic plasticity of the dentate gyrus that likely contributes to the learning.
Collapse
Affiliation(s)
- Kechun Yang
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - John I Broussard
- Department of Neuroscience, Center on Addiction, Learning, Memory, Baylor College of Medicine, Houston, TX, USA
| | - Amber T Levine
- Department of Neuroscience, Center on Addiction, Learning, Memory, Baylor College of Medicine, Houston, TX, USA
| | - Daniel Jenson
- Department of Neuroscience, Center on Addiction, Learning, Memory, Baylor College of Medicine, Houston, TX, USA
| | - Benjamin R Arenkiel
- Program in Developmental Biology, Jan and Dan Duncan Neurological Research Institute, Baylor College of Medicine, Texas Children's Hospital, Houston, TX, USA
| | - John A Dani
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| |
Collapse
|
38
|
Twarkowski H, Manahan-Vaughan D. Loss of Catecholaminergic Neuromodulation of Persistent Forms of Hippocampal Synaptic Plasticity with Increasing Age. Front Synaptic Neurosci 2016; 8:30. [PMID: 27725799 PMCID: PMC5035743 DOI: 10.3389/fnsyn.2016.00030] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 09/06/2016] [Indexed: 12/31/2022] Open
Abstract
Neuromodulation by means of the catecholaminergic system is a key component of motivation-driven learning and behaviorally modulated hippocampal synaptic plasticity. In particular, dopamine acting on D1/D5 receptors and noradrenaline acting on beta-adrenergic receptors exert a very potent regulation of forms of hippocampal synaptic plasticity that last for very long-periods of time (>24 h), and occur in conjunction with novel spatial learning. Antagonism of these receptors not only prevents long-term potentiation (LTP) and long-term depression (LTD), but prevents the memory of the spatial event that, under normal circumstances, leads to the perpetuation of these plasticity forms. Spatial learning behavior that normally comes easily to rats, such as object-place learning and spatial reference learning, becomes increasingly impaired with aging. Middle-aged animals display aging-related deficits of specific, but not all, components of spatial learning, and one possibility is that this initial manifestation of decrements in learning ability that become apparent in middle-age relate to changes in motivation, attention and/or the regulation by neuromodulatory systems of these behavioral states. Here, we compared the regulation by dopaminergic D1/D5 and beta-adrenergic receptors of persistent LTP in young (2-4 month old) and middle-aged (8-14 month old) rats. We observed in young rats, that weak potentiation that typically lasts for ca. 2 h could be strengthened into persistent (>24 h) LTP by pharmacological activation of either D1/D5 or beta-adrenergic receptors. By contrast, no such facilitation occurred in middle-aged rats. This difference was not related to an ostensible learning deficit: a facilitation of weak potentiation into LTP by spatial learning was possible both in young and middle-aged rats. It was also not directly linked to deficits in LTP: strong afferent stimulation resulted in equivalent LTP in both age groups. We postulate that this change in catecholaminergic control of synaptic plasticity that emerges with aging, does not relate to a learning deficit per se, rather it derives from an increase in behavioral thresholds for novelty and motivation that emerge with increasing age that impact, in turn, on learning efficacy.
Collapse
Affiliation(s)
- Hannah Twarkowski
- Department of Neurophysiology, Medical Faculty, Ruhr University BochumBochum, Germany; International Graduate School of Neuroscience, Ruhr University BochumBochum, Germany
| | | |
Collapse
|
39
|
Vishnoi S, Raisuddin S, Parvez S. Behavioral tagging: A novel model for studying long-term memory. Neurosci Biobehav Rev 2016; 68:361-369. [PMID: 27216211 DOI: 10.1016/j.neubiorev.2016.05.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 04/10/2016] [Accepted: 05/19/2016] [Indexed: 12/21/2022]
Abstract
New information acquired by our brain is stored in the form of two types of memories: short term memory (STM) and long term memory (LTM). Initially, Synaptic and Capture hypothesis has been proposed to describe the synaptic changes that occur during memory formation. However, recently Behavioral Tagging hypothesis was proposed that relies on the setting of a learning tag and the synthesis of plasticity related proteins (PRPs). Behavioral Tagging has its roots in Synaptic and Capture hypothesis. It seeks to explain that how a learning tag produced as a result of weak training can be paired up with PRPs (formed as a result of novelty) and can lead to long lasting memories. We have focused on describing behavioral paradigms that have been used for establishing the model of "Behavioral Tagging" and the molecules which qualify for potential PRP candidature.
Collapse
Affiliation(s)
- Shruti Vishnoi
- Department of Medical Elementology and Toxicology, Jamia Hamdard (Hamdard University), New Delhi 110062, India
| | - Sheikh Raisuddin
- Department of Medical Elementology and Toxicology, Jamia Hamdard (Hamdard University), New Delhi 110062, India
| | - Suhel Parvez
- Department of Medical Elementology and Toxicology, Jamia Hamdard (Hamdard University), New Delhi 110062, India.
| |
Collapse
|
40
|
Hagena H, Hansen N, Manahan-Vaughan D. β-Adrenergic Control of Hippocampal Function: Subserving the Choreography of Synaptic Information Storage and Memory. Cereb Cortex 2016; 26:1349-64. [PMID: 26804338 PMCID: PMC4785955 DOI: 10.1093/cercor/bhv330] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Noradrenaline (NA) is a key neuromodulator for the regulation of behavioral state and cognition. It supports learning by increasing arousal and vigilance, whereby new experiences are “earmarked” for encoding. Within the hippocampus, experience-dependent information storage occurs by means of synaptic plasticity. Furthermore, novel spatial, contextual, or associative learning drives changes in synaptic strength, reflected by the strengthening of long-term potentiation (LTP) or long-term depression (LTD). NA acting on β-adrenergic receptors (β-AR) is a key determinant as to whether new experiences result in persistent hippocampal synaptic plasticity. This can even dictate the direction of change of synaptic strength. The different hippocampal subfields play different roles in encoding components of a spatial representation through LTP and LTD. Strikingly, the sensitivity of synaptic plasticity in these subfields to β-adrenergic control is very distinct (dentate gyrus > CA3 > CA1). Moreover, NA released from the locus coeruleus that acts on β-AR leads to hippocampal LTD and an enhancement of LTD-related memory processing. We propose that NA acting on hippocampal β-AR, that is graded according to the novelty or saliency of the experience, determines the content and persistency of synaptic information storage in the hippocampal subfields and therefore of spatial memories.
Collapse
Affiliation(s)
- Hardy Hagena
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
| | - Niels Hansen
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
| | | |
Collapse
|
41
|
Clewett DV, Lee TH, Greening S, Ponzio A, Margalit E, Mather M. Neuromelanin marks the spot: identifying a locus coeruleus biomarker of cognitive reserve in healthy aging. Neurobiol Aging 2016; 37:117-126. [PMID: 26521135 PMCID: PMC5134892 DOI: 10.1016/j.neurobiolaging.2015.09.019] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 09/18/2015] [Accepted: 09/23/2015] [Indexed: 12/21/2022]
Abstract
Leading a mentally stimulating life may build up a reserve of neural and mental resources that preserve cognitive abilities in late life. Recent autopsy evidence links neuronal density in the locus coeruleus (LC), the brain's main source of norepinephrine, to slower cognitive decline before death, inspiring the idea that the noradrenergic system is a key component of reserve (Robertson, I. H. 2013. A noradrenergic theory of cognitive reserve: implications for Alzheimer's disease. Neurobiol. Aging. 34, 298-308). Here, we tested this hypothesis using neuromelanin-sensitive magnetic resonance imaging to visualize and measure LC signal intensity in healthy younger and older adults. Established proxies of reserve, including education, occupational attainment, and verbal intelligence, were linearly correlated with LC signal intensity in both age groups. Results indicated that LC signal intensity was significantly higher in older than younger adults and significantly lower in women than in men. Consistent with the LC-reserve hypothesis, both verbal intelligence and a composite reserve score were positively associated with LC signal intensity in older adults. LC signal intensity was also more strongly associated with attentional shifting ability in older adults with lower cognitive reserve. Together these findings link in vivo estimates of LC neuromelanin signal intensity to cognitive reserve in normal aging.
Collapse
Affiliation(s)
- David V Clewett
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA.
| | - Tae-Ho Lee
- Department of Psychology, University of Southern California, Los Angeles, CA, USA
| | - Steven Greening
- Department of Psychology, University of Southern California, Los Angeles, CA, USA; Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA; Department of Psychology, Louisiana State University, Baton Rouge, LA, USA
| | - Allison Ponzio
- Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Eshed Margalit
- Dornsife College of Letters and Sciences, University of Southern California, Los Angeles, CA, USA
| | - Mara Mather
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA; Department of Psychology, University of Southern California, Los Angeles, CA, USA; Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| |
Collapse
|
42
|
Maity S, Rah S, Sonenberg N, Gkogkas CG, Nguyen PV. Norepinephrine triggers metaplasticity of LTP by increasing translation of specific mRNAs. ACTA ACUST UNITED AC 2015; 22:499-508. [PMID: 26373828 PMCID: PMC4579357 DOI: 10.1101/lm.039222.115] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 06/30/2015] [Indexed: 12/24/2022]
Abstract
Norepinephrine (NE) is a key modulator of synaptic plasticity in the hippocampus, a brain structure crucially involved in memory formation. NE boosts synaptic plasticity mostly through initiation of signaling cascades downstream from beta (β)-adrenergic receptors (β-ARs). Previous studies demonstrated that a β-adrenergic receptor agonist, isoproterenol, can modify the threshold for long-term potentiation (LTP), a putative cellular mechanism for learning and memory, in a process known as “metaplasticity.” Metaplasticity is the ability of synaptic plasticity to be modified by prior experience. We asked whether NE itself could engage metaplastic mechanisms in area CA1 of mouse hippocampal slices. Using extracellular field potential recording and stimulation, we show that application of NE (10 µM), which did not alter basal synaptic strength, enhances the future maintenance of LTP elicited by subthreshold, high-frequency stimulation (HFS: 1 × 100 Hz, 1 sec). HFS applied 30 min after NE washout induced long-lasting (>4 h) LTP, which was significantly extended in duration relative to HFS alone. This NE-induced metaplasticity required β1-AR activation, as coapplication of the β1-receptor antagonist CGP-20712A (1 µM) attenuated maintenance of LTP. We also found that NE-mediated metaplasticity was translation- and transcription-dependent. Polysomal profiles of CA1 revealed increased translation rates for specific mRNAs during NE-induced metaplasticity. Thus, activation of β-ARs by NE primes synapses for future long-lasting plasticity on time scales extending beyond fast synaptic transmission; this may facilitate neural information processing and the subsequent formation of lasting memories.
Collapse
Affiliation(s)
- Sabyasachi Maity
- Department of Physiology, University of Alberta School of Medicine, Edmonton, Alberta T6G 2H7, Canada
| | - Sean Rah
- Department of Physiology, University of Alberta School of Medicine, Edmonton, Alberta T6G 2H7, Canada
| | - Nahum Sonenberg
- Department of Biochemistry, Goodman Cancer Centre, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Christos G Gkogkas
- Patrick Wild Centre and Centre for Integrative Biology, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Peter V Nguyen
- Department of Physiology, University of Alberta School of Medicine, Edmonton, Alberta T6G 2H7, Canada Department of Psychiatry, University of Alberta School of Medicine, Edmonton, Alberta T6G 2H7, Canada Neuroscience and Mental Health Institute, University of Alberta School of Medicine, Edmonton, Alberta T6G 2H7, Canada
| |
Collapse
|
43
|
Behavioral Tagging: A Translation of the Synaptic Tagging and Capture Hypothesis. Neural Plast 2015; 2015:650780. [PMID: 26380117 PMCID: PMC4562088 DOI: 10.1155/2015/650780] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 03/12/2015] [Indexed: 11/18/2022] Open
Abstract
Similar molecular machinery is activated in neurons following an electrical stimulus that induces synaptic changes and after learning sessions that trigger memory formation. Then, to achieve perdurability of these processes protein synthesis is required for the reinforcement of the changes induced in the network. The synaptic tagging and capture theory provided a strong framework to explain synaptic specificity and persistence of electrophysiological induced plastic changes. Ten years later, the behavioral tagging hypothesis (BT) made use of the same argument, applying it to learning and memory models. The hypothesis postulates that the formation of lasting memories relies on at least two processes: the setting of a learning tag and the synthesis of plasticity related proteins, which once captured at tagged sites allow memory consolidation. BT explains how weak events, only capable of inducing transient forms of memories, can result in lasting memories when occurring close in time with other behaviorally relevant experiences that provide proteins. In this review, we detail the findings supporting the existence of BT process in rodents, leading to the consolidation, persistence, and interference of a memory. We focus on the molecular machinery taking place in these processes and describe the experimental data supporting the BT in humans.
Collapse
|
44
|
Role of hippocampal β-adrenergic and glucocorticoid receptors in the novelty-induced enhancement of fear extinction. J Neurosci 2015; 35:8308-21. [PMID: 26019344 DOI: 10.1523/jneurosci.0005-15.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Fear extinction forms a new memory but does not erase the original fear memory. Exposure to novelty facilitates transfer of short-term extinction memory to long-lasting memory. However, the underlying cellular and molecular mechanisms are still unclear. Using a classical contextual fear-conditioning model, we investigated the effect of novelty on long-lasting extinction memory in rats. We found that exposure to a novel environment but not familiar environment 1 h before or after extinction enhanced extinction long-term memory (LTM) and reduced fear reinstatement. However, exploring novelty 6 h before or after extinction had no such effect. Infusion of the β-adrenergic receptor (βAR) inhibitor propranolol and glucocorticoid receptor (GR) inhibitor RU486 into the CA1 area of the dorsal hippocampus before novelty exposure blocked the effect of novelty on extinction memory. Propranolol prevented activation of the hippocampal PKA-CREB pathway, and RU486 prevented activation of the hippocampal extracellular signal-regulated kinase 1/2 (Erk1/2)-CREB pathway induced by novelty exposure. These results indicate that the hippocampal βAR-PKA-CREB and GR-Erk1/2-CREB pathways mediate the extinction-enhancing effect of novelty exposure. Infusion of RU486 or the Erk1/2 inhibitor U0126, but not propranolol or the PKA inhibitor Rp-cAMPS, into the CA1 before extinction disrupted the formation of extinction LTM, suggesting that hippocampal GR and Erk1/2 but not βAR or PKA play critical roles in this process. These results indicate that novelty promotes extinction memory via hippocampal βAR- and GR-dependent pathways, and Erk1/2 may serve as a behavioral tag of extinction.
Collapse
|
45
|
Norepinephrine ignites local hotspots of neuronal excitation: How arousal amplifies selectivity in perception and memory. Behav Brain Sci 2015; 39:e200. [PMID: 26126507 DOI: 10.1017/s0140525x15000667] [Citation(s) in RCA: 337] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Emotional arousal enhances perception and memory of high-priority information but impairs processing of other information. Here, we propose that, under arousal, local glutamate levels signal the current strength of a representation and interact with norepinephrine (NE) to enhance high priority representations and out-compete or suppress lower priority representations. In our "glutamate amplifies noradrenergic effects" (GANE) model, high glutamate at the site of prioritized representations increases local NE release from the locus coeruleus (LC) to generate "NE hotspots." At these NE hotspots, local glutamate and NE release are mutually enhancing and amplify activation of prioritized representations. In contrast, arousal-induced LC activity inhibits less active representations via two mechanisms: 1) Where there are hotspots, lateral inhibition is amplified; 2) Where no hotspots emerge, NE levels are only high enough to activate low-threshold inhibitory adrenoreceptors. Thus, LC activation promotes a few hotspots of excitation in the context of widespread suppression, enhancing high priority representations while suppressing the rest. Hotspots also help synchronize oscillations across neural ensembles transmitting high-priority information. Furthermore, brain structures that detect stimulus priority interact with phasic NE release to preferentially route such information through large-scale functional brain networks. A surge of NE before, during, or after encoding enhances synaptic plasticity at NE hotspots, triggering local protein synthesis processes that enhance selective memory consolidation. Together, these noradrenergic mechanisms promote selective attention and memory under arousal. GANE not only reconciles apparently contradictory findings in the emotion-cognition literature but also extends previous influential theories of LC neuromodulation by proposing specific mechanisms for how LC-NE activity increases neural gain.
Collapse
|
46
|
Hansen N, Manahan-Vaughan D. Hippocampal long-term potentiation that is elicited by perforant path stimulation or that occurs in conjunction with spatial learning is tightly controlled by beta-adrenoreceptors and the locus coeruleus. Hippocampus 2015; 25:1285-98. [PMID: 25727388 PMCID: PMC6680149 DOI: 10.1002/hipo.22436] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2015] [Indexed: 11/19/2022]
Abstract
The noradrenergic system, driven by locus coeruleus (LC) activation, plays a key role in the regulating and directing of changes in hippocampal synaptic efficacy. The LC releases noradrenaline in response to novel experience and LC activation leads to an enhancement of hippocampus‐based learning, and facilitates synaptic plasticity in the form of long‐term depression (LTD) and long‐term potentiation (LTP) that occur in association with spatial learning. The predominant receptor for mediating these effects is the β‐adrenoreceptor. Interestingly, the dependency of synaptic plasticity on this receptor is different in the hippocampal subfields whereby in the CA1 in vivo, LTP, but not LTD requires β‐adrenoreceptor activation, whereas in the mossy fiber synapse LTP and LTD do not depend on this receptor. By contrast, synaptic plasticity that is facilitated by spatial learning is highly dependent on β‐adrenoreceptor activation in both hippocampal subfields. Here, we explored whether LTP induced by perforant‐path (pp) stimulation in vivo or that is facilitated by spatial learning depends on β‐adrenoreceptors. We found that under both LTP conditions, antagonising the receptors disabled the persistence of LTP. β‐adrenoreceptor‐antagonism also prevented spatial learning. Strikingly, activation of the LC before high‐frequency stimulation (HFS) of the pp prevented short‐term potentiation but not LTP, and LC stimulation after pp‐HFS‐induced depotentiation of LTP. This depotentiation was prevented by β‐adrenoreceptor‐antagonism. These data suggest that β‐adrenoreceptor‐activation, resulting from noradrenaline release from the LC during enhanced arousal and learning, comprises a mechanism whereby the duration and degree of LTP is regulated and fine tuned. This may serve to optimize the creation of a spatial memory engram by means of LTP and LTD. This process can be expected to support the special role of the dentate gyrus as a crucial subregional locus for detecting and processing novelty within the hippocampus. © 2015 The Authors Hippocampus Published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Niels Hansen
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
| | | |
Collapse
|
47
|
Colettis NC, Snitcofsky M, Kornisiuk EE, Gonzalez EN, Quillfeldt JA, Jerusalinsky DA. Amnesia of inhibitory avoidance by scopolamine is overcome by previous open-field exposure. ACTA ACUST UNITED AC 2014; 21:634-45. [PMID: 25322799 PMCID: PMC4201807 DOI: 10.1101/lm.036210.114] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The muscarinic cholinergic receptor (MAChR) blockade with scopolamine either extended or restricted to the hippocampus, before or after training in inhibitory avoidance (IA) caused anterograde or retrograde amnesia, respectively, in the rat, because there was no long-term memory (LTM) expression. Adult Wistar rats previously exposed to one or two open-field (OF) sessions of 3 min each (habituated), behaved as control animals after a weak though over-threshold training in IA. However, after OF exposure, IA LTM was formed and expressed in spite of an extensive or restricted to the hippocampus MAChR blockade. It was reported that during and after OF exposure and reexposure there was an increase in both hippocampal and cortical ACh release that would contribute to “prime the substrate,” e.g., by lowering the synaptic threshold for plasticity, leading to LTM consolidation. In the frame of the “synaptic tagging and capture” hypothesis, plasticity-related proteins synthesized during/after the previous OF could facilitate synaptic plasticity for IA in the same structure. However, IA anterograde amnesia by hippocampal protein synthesis inhibition with anisomycin was also prevented by two OF exposures, strongly suggesting that there would be alternative interpretations for the role of protein synthesis in memory formation and that another structure could also be involved in this “OF effect.”
Collapse
Affiliation(s)
- Natalia C Colettis
- Laboratorio de Neuroplasticidad y Neurotoxinas (LaNyN), Instituto de Biología Celular y Neurociencias (IBCN), UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires 1121, Argentina
| | - Marina Snitcofsky
- Laboratorio de Neuroplasticidad y Neurotoxinas (LaNyN), Instituto de Biología Celular y Neurociencias (IBCN), UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires 1121, Argentina
| | - Edgar E Kornisiuk
- Laboratorio de Neuroplasticidad y Neurotoxinas (LaNyN), Instituto de Biología Celular y Neurociencias (IBCN), UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires 1121, Argentina
| | - Emilio N Gonzalez
- Laboratorio de Neuroplasticidad y Neurotoxinas (LaNyN), Instituto de Biología Celular y Neurociencias (IBCN), UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires 1121, Argentina
| | - Jorge A Quillfeldt
- Laboratório de Psicobiologia e Neurocomputação, Depto. de Biofísica, UFRGS, Porto Alegre 91501-970, Brazil
| | - Diana A Jerusalinsky
- Laboratorio de Neuroplasticidad y Neurotoxinas (LaNyN), Instituto de Biología Celular y Neurociencias (IBCN), UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires 1121, Argentina
| |
Collapse
|
48
|
Bhagya V, Srikumar B, Raju T, Shankaranarayana Rao B. The selective noradrenergic reuptake inhibitor reboxetine restores spatial learning deficits, biochemical changes, and hippocampal synaptic plasticity in an animal model of depression. J Neurosci Res 2014; 93:104-20. [DOI: 10.1002/jnr.23473] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 07/07/2014] [Accepted: 07/24/2014] [Indexed: 12/21/2022]
Affiliation(s)
- V. Bhagya
- Department of Neurophysiology; National Institute of Mental Health and Neuro Sciences; Bangalore India
| | - B.N. Srikumar
- Department of Neurophysiology; National Institute of Mental Health and Neuro Sciences; Bangalore India
| | - T.R. Raju
- Department of Neurophysiology; National Institute of Mental Health and Neuro Sciences; Bangalore India
| | - B.S. Shankaranarayana Rao
- Department of Neurophysiology; National Institute of Mental Health and Neuro Sciences; Bangalore India
| |
Collapse
|
49
|
Schomaker J, van Bronkhorst MLV, Meeter M. Exploring a novel environment improves motivation and promotes recall of words. Front Psychol 2014; 5:918. [PMID: 25191297 PMCID: PMC4138787 DOI: 10.3389/fpsyg.2014.00918] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 08/01/2014] [Indexed: 11/14/2022] Open
Abstract
Active exploration of novel environments is known to increase plasticity in animals, promoting long-term potentiation in the hippocampus and enhancing memory formation. These effects can occur during as well as after exploration. In humans novelty’s effects on memory have been investigated with other methods, but never in an active exploration paradigm. We therefore investigated whether active spatial exploration of a novel compared to a previously familiarized virtual environment promotes performance on an unrelated word learning task. Exploration of the novel environment enhanced recall, generally thought to be hippocampus-dependent, but not recognition, believed to rely less on the hippocampus. Recall was better for participants that gave higher presence ratings for their experience in the virtual environment. These ratings were higher for the novel compared to the familiar virtual environment, suggesting that novelty increased attention for the virtual rather than real environment; however, this did not explain the effect of novelty on recall.
Collapse
Affiliation(s)
- Judith Schomaker
- Department of Cognitive Psychology, VU University Amsterdam Amsterdam, Noord-Holland, Netherlands
| | | | - Martijn Meeter
- Department of Cognitive Psychology, VU University Amsterdam Amsterdam, Noord-Holland, Netherlands
| |
Collapse
|
50
|
l-DOPA reverses the impairment of Dentate Gyrus LTD in experimental parkinsonism via β-adrenergic receptors. Exp Neurol 2014; 261:377-85. [PMID: 25058044 DOI: 10.1016/j.expneurol.2014.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/30/2014] [Accepted: 07/08/2014] [Indexed: 11/20/2022]
Abstract
Parkinson's disease (PD) patients exhibit motor and non-motor symptoms that severely affect quality of life. Cognitive alterations in PD subjects have been related to both structural and functional hippocampal changes. Here we investigated the effects of the 6-hydroxydopamine (6-OHDA) lesion in the Medial Forebrain Bundle (MFB) on the hippocampus focusing on the Dentate Gyrus (DG). In vivo microdialysis measurements revealed that the 6-OHDA injection disrupts both dopaminergic and noradrenergic transmission in rat DG. In vitro electrophysiological recordings showed that these neurochemical alterations were accompanied by impairment of long-term depression (LTD) at medial perforant path/DG synapses. Furthermore, this alteration was reversed by l-DOPA treatment. Notably, the therapeutic effect of l-DOPA on LTD was blocked by the antagonism of β-noradrenergic receptors, but not by dopamine D1 or D2 receptor antagonists. Thus, while the dopaminergic transmission does not seem to be implicated in this therapeutic effect of l-DOPA, the noradrenergic system plays a central role in the synaptic dysfunction of the DG in experimental PD. Our work provides new evidence on the role of catecholamines in DG synaptic plasticity and sheds light on the possible synaptic mechanisms underlying cognitive deficits in PD. Furthermore, our results indicate that l-DOPA exerts a therapeutic effect on the parkinsonian brain through different, coexistent, mechanisms.
Collapse
|