1
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Tsokas P, Hsieh C, Flores-Obando RE, Bernabo M, Tcherepanov A, Hernández AI, Thomas C, Bergold PJ, Cottrell JE, Kremerskothen J, Shouval HZ, Nader K, Fenton AA, Sacktor TC. KIBRA anchoring the action of PKMζ maintains the persistence of memory. SCIENCE ADVANCES 2024; 10:eadl0030. [PMID: 38924398 PMCID: PMC11204205 DOI: 10.1126/sciadv.adl0030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 05/23/2024] [Indexed: 06/28/2024]
Abstract
How can short-lived molecules selectively maintain the potentiation of activated synapses to sustain long-term memory? Here, we find kidney and brain expressed adaptor protein (KIBRA), a postsynaptic scaffolding protein genetically linked to human memory performance, complexes with protein kinase Mzeta (PKMζ), anchoring the kinase's potentiating action to maintain late-phase long-term potentiation (late-LTP) at activated synapses. Two structurally distinct antagonists of KIBRA-PKMζ dimerization disrupt established late-LTP and long-term spatial memory, yet neither measurably affects basal synaptic transmission. Neither antagonist affects PKMζ-independent LTP or memory that are maintained by compensating PKCs in ζ-knockout mice; thus, both agents require PKMζ for their effect. KIBRA-PKMζ complexes maintain 1-month-old memory despite PKMζ turnover. Therefore, it is not PKMζ alone, nor KIBRA alone, but the continual interaction between the two that maintains late-LTP and long-term memory.
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Affiliation(s)
- Panayiotis Tsokas
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Health Sciences University, Brooklyn, NY 11203, USA
- Department of Anesthesiology, State University of New York Downstate Health Sciences University, Brooklyn, NY 11203, USA
| | - Changchi Hsieh
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Health Sciences University, Brooklyn, NY 11203, USA
| | - Rafael E. Flores-Obando
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Health Sciences University, Brooklyn, NY 11203, USA
| | - Matteo Bernabo
- Department of Psychology, McGill University, Montreal, Quebec H3A 1G1, Canada
| | - Andrew Tcherepanov
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Health Sciences University, Brooklyn, NY 11203, USA
| | - A. Iván Hernández
- Department of Pathology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Health Sciences University, Brooklyn, NY 11203, USA
| | - Christian Thomas
- Internal Medicine D (MedD), Department of Molecular Nephrology, University Hospital of Münster, 48149 Münster, Germany
| | - Peter J. Bergold
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Health Sciences University, Brooklyn, NY 11203, USA
| | - James E. Cottrell
- Department of Anesthesiology, State University of New York Downstate Health Sciences University, Brooklyn, NY 11203, USA
| | - Joachim Kremerskothen
- Internal Medicine D (MedD), Department of Molecular Nephrology, University Hospital of Münster, 48149 Münster, Germany
| | - Harel Z. Shouval
- Department of Neurobiology and Anatomy, University of Texas Medical at Houston, Houston, TX 77030, USA
| | - Karim Nader
- Department of Psychology, McGill University, Montreal, Quebec H3A 1G1, Canada
| | - André A. Fenton
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Health Sciences University, Brooklyn, NY 11203, USA
- Center for Neural Science, New York University, New York, NY 10003, USA
- Neuroscience Institute at NYU Langone Medical Center, New York, NY 10016, USA
| | - Todd C. Sacktor
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Health Sciences University, Brooklyn, NY 11203, USA
- Department of Anesthesiology, State University of New York Downstate Health Sciences University, Brooklyn, NY 11203, USA
- Department of Neurology, State University of New York Downstate Health Sciences University, Brooklyn, NY 11203, USA
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2
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Ko T, Jou C, Grau-Perales AB, Reynders M, Fenton AA, Trauner D. Photoactivated Protein Degrader for Optical Control of Synaptic Function. ACS Chem Neurosci 2023; 14:3704-3713. [PMID: 37712589 PMCID: PMC10557063 DOI: 10.1021/acschemneuro.3c00390] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 08/04/2023] [Indexed: 09/16/2023] Open
Abstract
Hundreds of proteins determine the function of synapses, and synapses define the neuronal circuits that subserve myriad brain, cognitive, and behavioral functions. It is thus necessary to precisely manipulate specific proteins at specific sub-cellular locations and times to elucidate the roles of particular proteins and synapses in brain function. We developed PHOtochemically TArgeting Chimeras (PHOTACs) as a strategy to optically degrade specific proteins with high spatial and temporal precision. PHOTACs are small molecules that, upon wavelength-selective illumination, catalyze ubiquitylation and degradation of target proteins through endogenous proteasomes. Here, we describe the design and chemical properties of a PHOTAC that targets Ca2+/calmodulin-dependent protein kinase II alpha (CaMKIIα), which is abundant and crucial for the baseline synaptic function of excitatory neurons. We validate the PHOTAC strategy, showing that the CaMKIIα-PHOTAC is effective in mouse brain tissue. Light activation of CaMKIIα-PHOTAC removed CaMKIIα from regions of the mouse hippocampus only within 25 μm of the illuminated brain surface. The optically controlled degradation decreases synaptic function within minutes of light activation, measured by the light-initiated attenuation of evoked field excitatory postsynaptic potential (fEPSP) responses to physiological stimulation. The PHOTACs methodology should be broadly applicable to other key proteins implicated in synaptic function, especially for evaluating their precise roles in the maintenance of long-term potentiation and memory within subcellular dendritic domains.
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Affiliation(s)
- Tongil Ko
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department
of Chemistry, New York University, New York, New York 10003, United States
| | - Claudia Jou
- Department
of Psychology, Hunter College, New York, New York 10065, United States
| | | | - Martin Reynders
- Department
of Chemistry, New York University, New York, New York 10003, United States
| | - André A. Fenton
- Center
for Neural Science, New York University, New York, New York 10003, United States
| | - Dirk Trauner
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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3
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Ko T, Jou C, Grau-Perales A, Reynders M, Fenton A, Trauner D. A Photoactivated Protein Degrader for Optical Control of Synaptic Function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.13.528397. [PMID: 36824807 PMCID: PMC9949324 DOI: 10.1101/2023.02.13.528397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Hundreds of proteins determine the function of synapses, and synapses define the neuronal circuits that subserve myriad brain, cognitive, and behavioral functions. It is thus necessary to precisely manipulate specific proteins at specific sub-cellular locations and times to elucidate the roles of particular proteins and synapses in brain function. We developed PHOtochemically TArgeting Chimeras (PHOTACs) as a strategy to optically degrade specific proteins with high spatial and temporal precision. PHOTACs are small molecules that, upon wavelength-selective illumination, catalyze ubiquitylation and degradation of target proteins through endogenous proteasomes. Here we describe the design and chemical properties of a PHOTAC that targets Ca 2+ /calmodulin-dependent protein kinase II alpha (CaMKIIα), which is abundant and crucial for baseline synaptic function of excitatory neurons. We validate the PHOTAC strategy, showing that the CaMKIIα-PHOTAC is effective in mouse brain tissue. Light activation of CaMKIIα-PHOTAC removed CaMKIIα from regions of the mouse hippocampus only within 25 μm of the illuminated brain surface. The optically-controlled degradation decreases synaptic function within minutes of light activation, measured by the light-initiated attenuation of evoked field excitatory postsynaptic potential (fEPSP) responses to physiological stimulation. The PHOTACs methodology should be broadly applicable to other key proteins implicated in synaptic function, especially for evaluating their precise roles in the maintenance of long-term potentiation and memory within subcellular dendritic domains.
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Affiliation(s)
- T. Ko
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street Philadelphia, PA 19104-6323, USA
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - C. Jou
- Department of Psychology, Hunter College, 695 Park Avenue, New York, NY, 10065, USA
| | - A.B. Grau-Perales
- Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA
| | - M. Reynders
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - A.A. Fenton
- Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA
| | - D. Trauner
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street Philadelphia, PA 19104-6323, USA
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, USA
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aPKC in neuronal differentiation, maturation and function. Neuronal Signal 2019; 3:NS20190019. [PMID: 32269838 PMCID: PMC7104321 DOI: 10.1042/ns20190019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/10/2019] [Accepted: 09/11/2019] [Indexed: 12/17/2022] Open
Abstract
The atypical Protein Kinase Cs (aPKCs)—PRKCI, PRKCZ and PKMζ—form a subfamily within the Protein Kinase C (PKC) family. These kinases are expressed in the nervous system, including during its development and in adulthood. One of the aPKCs, PKMζ, appears to be restricted to the nervous system. aPKCs are known to play a role in a variety of cellular responses such as proliferation, differentiation, polarity, migration, survival and key metabolic functions such as glucose uptake, that are critical for nervous system development and function. Therefore, these kinases have garnered a lot of interest in terms of their functional role in the nervous system. Here we review the expression and function of aPKCs in neural development and in neuronal maturation and function. Despite seemingly paradoxical findings with genetic deletion versus gene silencing approaches, we posit that aPKCs are likely candidates for regulating many important neurodevelopmental and neuronal functions, and may be associated with a number of human neuropsychiatric diseases.
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Chau DDL, Yung KWY, Chan WWL, An Y, Hao Y, Chan HYE, Ngo JCK, Lau KF. Attenuation of amyloid-β generation by atypical protein kinase C-mediated phosphorylation of engulfment adaptor PTB domain containing 1 threonine 35. FASEB J 2019; 33:12019-12035. [PMID: 31373844 DOI: 10.1096/fj.201802825rr] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Amyloid-β (Aβ) is derived from the proteolytic processing of amyloid precursor protein (APP), and the deposition of extracellular Aβ to form amyloid plaques is a pathologic hallmark of Alzheimer's disease (AD). Although reducing Aβ generation and accumulation has been proposed as a means of treating the disease, adverse side effects and unsatisfactory efficacy have been reported in several clinical trials that sought to lower Aβ levels. Engulfment adaptor phosphotyrosine-binding (PTB) domain containing 1 (GULP1) is a molecular adaptor that has been shown to interact with APP to alter Aβ production. Therefore, the modulation of the GULP1-APP interaction may be an alternative approach to reducing Aβ. However, the mechanisms that regulate GULP1-APP binding remain elusive. As GULP1 is a phosphoprotein, and because phosphorylation is a common mechanism that regulates protein interaction, we anticipated that GULP1 phosphorylation would influence GULP1-APP interaction and thereby Aβ production. We show here that the phosphorylation of GULP1 threonine 35 (T35) reduces GULP1-APP interaction and suppresses the stimulatory effect of GULP1 on APP processing. The residue is phosphorylated by an isoform of atypical PKC (PKCζ). Overexpression of PKCζ reduces both GULP1-APP interaction and GULP1-mediated Aβ generation. Moreover, the activation of PKCζ via insulin suppresses APP processing. In contrast, GULP1-mediated APP processing is enhanced in PKCζ knockout cells. Similarly, PKC ι, another member of atypical PKC, also decreases GULP1-mediated APP processing. Intriguingly, our X-ray crystal structure of GULP1 PTB-APP intracellular domain (AICD) peptide reveals that GULP1 T35 is not located at the GULP1-AICD binding interface; rather, it immediately precedes the β1-α2 loop that forms a portion of the binding groove for the APP helix αC. Phosphorylating the residue may induce an allosteric effect on the conformation of the binding groove. Our results indicate that GULP1 T35 phosphorylation is a mechanism for the regulation of GULP1-APP interaction and thereby APP processing. Moreover, the activation of atypical PKC, such as by insulin, may confer a beneficial effect on AD by lowering GULP1-mediated Aβ production.-Chau, D. D.-L., Yung, K. W.-Y., Chan, W. W.-L., An, Y., Hao, Y., Chan, H.-Y. E., Ngo, J. C.-K., Lau, K.-F. Attenuation of amyloid-β generation by atypical protein kinase C-mediated phosphorylation of engulfment adaptor PTB domain containing 1 threonine 35.
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Affiliation(s)
- Dennis Dik-Long Chau
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Kristen Wing-Yu Yung
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - William Wai-Lun Chan
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Ying An
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Yan Hao
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Ho-Yin Edwin Chan
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Jacky Chi-Ki Ngo
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Kwok-Fai Lau
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
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6
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Bear MF, Cooke SF, Giese KP, Kaang BK, Kennedy MB, Kim JI, Morris RGM, Park P. In memoriam: John Lisman - commentaries on CaMKII as a memory molecule. Mol Brain 2018; 11:76. [PMID: 30593282 PMCID: PMC6309094 DOI: 10.1186/s13041-018-0419-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 10/24/2018] [Indexed: 11/10/2022] Open
Abstract
Shortly before he died in October 2017, John Lisman submitted an invited review to Molecular Brain on 'Criteria for identifying the molecular basis of the engram (CaMKII, PKMζ)'. John had no opportunity to read the referees' comments, and as a mark of the regard in which he was held by the neuroscience community the Editors decided to publish his review as submitted. This obituary takes the form of a series of commentaries on Lisman's review. At the same time we are publishing as a separate article a longer response by Todd Sacktor and André Fenton entitled 'What does LTP tell us about the roles of CaMKII and PKMζ in memory?' which presents the case for a rival memory molecule, PKMζ.
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Affiliation(s)
- Mark F. Bear
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Sam F. Cooke
- King’s College London, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, De Crespigny Park, London, SE5 8AF UK
| | - Karl Peter Giese
- King’s College London, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, De Crespigny Park, London, SE5 8AF UK
| | - Bong-Kiun Kaang
- Department of Biological Sciences, Seoul National University, Gwanak-gu, Seoul, Republic of Korea
| | - Mary B. Kennedy
- The Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125 USA
| | - Ji-il Kim
- Department of Biological Sciences, Seoul National University, Gwanak-gu, Seoul, Republic of Korea
| | - Richard G. M. Morris
- Laboratory for Cognitive Neuroscience, Centre for Discovery Brain Sciences, Edinburgh Neuroscience, Edinburgh, EH8 9JZ UK
| | - Pojeong Park
- Department of Biological Sciences, Seoul National University, Gwanak-gu, Seoul, Republic of Korea
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7
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Developmental transitions in amygdala PKC isoforms and AMPA receptor expression associated with threat memory in infant rats. Sci Rep 2018; 8:14679. [PMID: 30279521 PMCID: PMC6168531 DOI: 10.1038/s41598-018-32762-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 09/03/2018] [Indexed: 12/12/2022] Open
Abstract
Although infants learn and remember, they rapidly forget, a phenomenon known as infantile amnesia. While myriad mechanisms impact this rapid forgetting, the molecular events supporting memory maintenance have yet to be explored. To explore memory mechanisms across development, we used amygdala-dependent odor-shock conditioning and focused on mechanisms important in adult memory, the AMPA receptor subunits GluA1/2 and upstream protein kinases important for trafficking AMPAR, protein kinase M zeta (PKMζ) and iota/lambda (PKCι/λ). We use odor-shock conditioning in infant rats because it is late-developing (postnatal day, PN10) and can be modulated by corticosterone during a sensitive period in early life. Our results show that memory-related molecules did not change in pups too young to learn threat (PN8) but were activated in pups old enough to learn (PN12), with increased PKMζ-PKCι/λ and GluA2 similar to that observed in adult memory, but with an uncharacteristic decrease in GluA1. This molecular signature and behavioral avoidance of the conditioned odor was recapitulated in PN8 pups injected with CORT before conditioning to precociously induce learning. Blocking learning via CORT inhibition in older pups (PN12) blocked the expression of these molecules. PN16 pups showed a more adult-like molecular cascade of increased PKMζ-PKCι/λ and GluA1–2. Finally, at all ages, zeta inhibitory peptide (ZIP) infusions into the amygdala 24 hr after conditioning blocked memory. Together, these results identify unique features of memory processes across early development: AMPAR subunits GluA1/2 and PKC isoform expression are differentially used, which may contribute to mechanisms of early life forgetting.
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ZIP It: Neural Silencing Is an Additional Effect of the PKM-Zeta Inhibitor Zeta-Inhibitory Peptide. J Neurosci 2017; 36:6193-8. [PMID: 27277798 DOI: 10.1523/jneurosci.4563-14.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 04/25/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Protein kinase M ζ (PKMζ), an atypical isoform of protein kinase C, has been suggested to be necessary and sufficient for the maintenance of long-term potentiation (LTP) and long-term memory (LTM). This evidence is heavily based on the use of ζ inhibitory peptide (ZIP), a supposed specific inhibitor of PKMζ that interferes with both LTP and LTM. Problematically, both LTP and LTM are unaffected in both constitutive and conditional PKMζ knock-out mice, yet both are still impaired by ZIP application, suggesting a nonspecific mechanism of action. Because translational interference can disrupt neural activity, we assessed network activity after a unilateral intrahippocampal infusion of ZIP in anesthetized rats. ZIP profoundly reduced spontaneous hippocampal local field potentials, comparable in magnitude to infusions of lidocaine, but with a slower onset and longer duration. Our results highlight a serious confound in interpreting the behavioral effects of ZIP. We suggest that future molecular approaches in neuroscience consider the intervening level of cellular and systems neurophysiology before claiming influences on behavior. SIGNIFICANCE STATEMENT Long-term memory in the brain is thought to arise from a sustained molecular process that can maintain changes in synaptic plasticity. A so-called candidate for the title of "the memory molecule" is protein kinase M ζ (PKMζ), mainly because its inhibition by ζ inhibitory peptide (ZIP) interferes with previously established synaptic plasticity and memory. We show that brain applications of ZIP that can impair memory actually profoundly suppress spontaneous brain activity directly or can cause abnormal seizure activity. We suggest that normal brain activity occurring after learning may be a more primary element of memory permanence.
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9
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Wang S, Sheng T, Ren S, Tian T, Lu W. Distinct Roles of PKCι/λ and PKMζ in the Initiation and Maintenance of Hippocampal Long-Term Potentiation and Memory. Cell Rep 2016; 16:1954-61. [PMID: 27498875 DOI: 10.1016/j.celrep.2016.07.030] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/21/2016] [Accepted: 07/12/2016] [Indexed: 11/19/2022] Open
Abstract
PKMζ has been proposed to be essential for maintenance of long-term potentiation (LTP) and long-term memory (LTM). However, recent data from PKMζ-knockout mice has called this role into question. Instead, the other atypical isoform, protein kinase C iota/lambda (PKCι/λ), has emerged as a potential alternative player. Therefore, the nature of the "memory molecule" maintaining learned information remains uncertain. Here, we report knockdown (KD) of PKCι/λ and PKMζ in the dorsal hippocampus and find deficits in early expression and late maintenance, respectively, during both LTP and hippocampus-dependent LTM. Sequential increases in the active form of PKCι/λ and PKMζ are detected during LTP or fear conditioning. Importantly, PKMζ, but not PKCι/λ, KD disrupts previously established LTM. Thus, PKCι/λ and PKMζ have distinct functions in LTP and memory, with PKMζ playing a specific role in memory maintenance. This relaying pattern may represent a precise molecular mechanism by which atypical PKCs regulate the different stages of memory.
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Affiliation(s)
- Shaoli Wang
- The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing, Jiangsu Province 210096, China; Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Tao Sheng
- The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing, Jiangsu Province 210096, China; Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Siqiang Ren
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Tian Tian
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Wei Lu
- The Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University, Nanjing, Jiangsu Province 210096, China; Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province 226001, China.
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10
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Tsokas P, Hsieh C, Yao Y, Lesburguères E, Wallace EJC, Tcherepanov A, Jothianandan D, Hartley BR, Pan L, Rivard B, Farese RV, Sajan MP, Bergold PJ, Hernández AI, Cottrell JE, Shouval HZ, Fenton AA, Sacktor TC. Compensation for PKMζ in long-term potentiation and spatial long-term memory in mutant mice. eLife 2016; 5. [PMID: 27187150 PMCID: PMC4869915 DOI: 10.7554/elife.14846] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 03/23/2016] [Indexed: 02/07/2023] Open
Abstract
PKMζ is a persistently active PKC isoform proposed to maintain late-LTP and long-term memory. But late-LTP and memory are maintained without PKMζ in PKMζ-null mice. Two hypotheses can account for these findings. First, PKMζ is unimportant for LTP or memory. Second, PKMζ is essential for late-LTP and long-term memory in wild-type mice, and PKMζ-null mice recruit compensatory mechanisms. We find that whereas PKMζ persistently increases in LTP maintenance in wild-type mice, PKCι/λ, a gene-product closely related to PKMζ, persistently increases in LTP maintenance in PKMζ-null mice. Using a pharmacogenetic approach, we find PKMζ-antisense in hippocampus blocks late-LTP and spatial long-term memory in wild-type mice, but not in PKMζ-null mice without the target mRNA. Conversely, a PKCι/λ-antagonist disrupts late-LTP and spatial memory in PKMζ-null mice but not in wild-type mice. Thus, whereas PKMζ is essential for wild-type LTP and long-term memory, persistent PKCι/λ activation compensates for PKMζ loss in PKMζ-null mice. DOI:http://dx.doi.org/10.7554/eLife.14846.001 How are long-term memories stored in the brain? The formation of memories is believed to depend on the strengthening of connections between neurons. During learning, neurons produce an enzyme called PKMzeta (or PKMζ), which is thought to be responsible for maintaining the newly strengthened connections. Inhibitors of PKMzeta, such as a drug called ZIP, disrupt long-term memories. This suggests that the brain may be like a computer hard disc in that its stored information — its memories — could be erased. However, recent experiments on genetically engineered mice have thrown the role of PKMzeta into question. Knockout mice that lack the gene for PKMzeta can still strengthen connections between neurons and can still learn and remember. Moreover, ZIP still works to reverse the strengthening and to erase long-term memories. This indicates that ZIP can act on something other than the PKMzeta enzyme. These results have led many neuroscientists to doubt that PKMzeta has anything to do with memory. Yet there are two possible explanations for the normal memory in PKMzeta knockout mice. First, PKMzeta is not required for memory, so getting rid of it has no effect. Second, PKMzeta is essential for long-term memory in normal mice. However, knockout mice recruit a back-up mechanism for long-term memory storage, which is also sensitive to the effects of ZIP. To test these possibilities, Tsokas et al. used a modified piece of DNA that prevents neurons with the gene for PKMzeta from producing the enzyme. The DNA blocked memory formation in normal mice, consistent with a role for PKMzeta in memory. However, it had no effect in knockout mice — the DNA had nothing to work on. This suggests that another molecule does indeed act as a back-up for PKMzeta in these animals. Further experiments revealed that an enzyme closely related to PKMzeta, called PKCiota/lambda (PKCι/λ), substitutes for PKMzeta during memory storage in the knockout mice. These findings restore PKMzeta to its early promise. They show that PKMzeta is crucial for long-term memory in normal mice, but that something as important as memory storage has a back-up mechanism should PKMzeta fail. Future work may reveal when and how this back-up becomes engaged. DOI:http://dx.doi.org/10.7554/eLife.14846.002
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Affiliation(s)
- Panayiotis Tsokas
- Department of Physiology and Pharmacology, The Robert F Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States.,Department of Anesthesiology, State University of New York Downstate Medical Center, Brooklyn, United States
| | - Changchi Hsieh
- Department of Physiology and Pharmacology, The Robert F Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
| | - Yudong Yao
- Department of Physiology and Pharmacology, The Robert F Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
| | | | - Emma Jane Claire Wallace
- Department of Physiology and Pharmacology, The Robert F Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
| | - Andrew Tcherepanov
- Department of Physiology and Pharmacology, The Robert F Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
| | - Desingarao Jothianandan
- Department of Physiology and Pharmacology, The Robert F Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
| | - Benjamin Rush Hartley
- Department of Physiology and Pharmacology, The Robert F Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
| | - Ling Pan
- Department of Physiology and Pharmacology, The Robert F Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
| | - Bruno Rivard
- Department of Physiology and Pharmacology, The Robert F Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
| | - Robert V Farese
- Department of Internal Medicine, James A Haley Veterans Hospital, University of South Florida, Tampa, United States
| | - Mini P Sajan
- Department of Internal Medicine, James A Haley Veterans Hospital, University of South Florida, Tampa, United States
| | - Peter John Bergold
- Department of Physiology and Pharmacology, The Robert F Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
| | - Alejandro Iván Hernández
- Department of Pathology, State University of New York Downstate Medical Center, Brooklyn, United States
| | - James E Cottrell
- Department of Anesthesiology, State University of New York Downstate Medical Center, Brooklyn, United States
| | - Harel Z Shouval
- Department of Neurobiology and Anatomy, University of Texas Medical School at Houston, Houston, United States
| | - André Antonio Fenton
- Department of Physiology and Pharmacology, The Robert F Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States.,Center for Neural Science, New York University, New York, United States
| | - Todd Charlton Sacktor
- Department of Physiology and Pharmacology, The Robert F Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States.,Department of Anesthesiology, State University of New York Downstate Medical Center, Brooklyn, United States.,Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, United States
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11
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Abstract
An enzyme called PKM zeta may have a role in long-term memory after all.
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Affiliation(s)
- Richard Gm Morris
- Centre for Cognitive and Neural Systems, University of Edinburgh, Edinburgh, United Kingdom
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12
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Jalil SJ, Sacktor TC, Shouval HZ. Atypical PKCs in memory maintenance: the roles of feedback and redundancy. ACTA ACUST UNITED AC 2015; 22:344-53. [PMID: 26077687 PMCID: PMC4478332 DOI: 10.1101/lm.038844.115] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 05/05/2015] [Indexed: 11/24/2022]
Abstract
Memories that last a lifetime are thought to be stored, at least in part, as persistent enhancement of the strength of particular synapses. The synaptic mechanism of these persistent changes, late long-term potentiation (L-LTP), depends on the state and number of specific synaptic proteins. Synaptic proteins, however, have limited dwell times due to molecular turnover and diffusion, leading to a fundamental question: how can this transient molecular machinery store memories lasting a lifetime? Because the persistent changes in efficacy are synapse-specific, the underlying molecular mechanisms must to a degree reside locally in synapses. Extensive experimental evidence points to atypical protein kinase C (aPKC) isoforms as key components involved in memory maintenance. Furthermore, it is evident that establishing long-term memory requires new protein synthesis. However, a comprehensive model has not been developed describing how these components work to preserve synaptic efficacies over time. We propose a molecular model that can account for key empirical properties of L-LTP, including its protein synthesis dependence, dependence on aPKCs, and synapse-specificity. Simulations and empirical data suggest that either of the two aPKC subtypes in hippocampal neurons, PKMζ and PKCι/λ, can maintain L-LTP, making the system more robust. Given genetic compensation at the level of synthesis of these PKC subtypes as in knockout mice, this system is able to maintain L-LTP and memory when one of the pathways is eliminated.
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Affiliation(s)
- Sajiya J Jalil
- Department of Neurobiology and Anatomy, The University of Texas Medical School at Houston, Houston, Texas 77030, USA
| | - Todd Charlton Sacktor
- Department of Physiology, Pharmacology, Anesthesiology, and Neurology, SUNY Downstate Medical Center, Brooklyn, New York 11203, USA
| | - Harel Z Shouval
- Department of Neurobiology and Anatomy, The University of Texas Medical School at Houston, Houston, Texas 77030, USA
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13
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Rudy JW. Variation in the persistence of memory: An interplay between actin dynamics and AMPA receptors. Brain Res 2014; 1621:29-37. [PMID: 25511990 DOI: 10.1016/j.brainres.2014.12.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 12/02/2014] [Accepted: 12/03/2014] [Indexed: 10/24/2022]
Abstract
William James noted that memories could persist from minutes to weeks. This essay attempts to explain this variation by situating the explanation in the biochemistry of dendritic spines. Two outcomes are critical to generate the synaptic basis of memory: (1) the actin cytoskeleton in the spine must be degraded to permit (2) additional AMPA receptors (GluA1s) to enter new "hot spots" in the postsynaptic density. These initial outcomes can support short-lasting memories. The threshold for these events is low but the underlying synaptic changes cannot resist the endocytic processes that remove the added AMPA receptors. For the memory to persist the degraded actin cytoskeleton must be rebuilt and the vacated "hot spots" refilled with GluA2 receptors. A primary claim is that it is the stabilization of an enlarged actin cytoskeleton that is the target outcome that consolidates the synaptic basis of memory (see Lynch et al., 2007). The stabilized actin cytoskeleton has properties that enable it to garner the synaptic proteins it needs to self sustain the potentiated state and to benefit from activation of memory modulation systems. This article is part of a Special Issue entitled Brain and Memory.
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Affiliation(s)
- Jerry W Rudy
- Department of Psychology and Neuroscience University of Colorado, Boulder, CO 80309, United States.
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14
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Deppermann S, Storchak H, Fallgatter A, Ehlis AC. Stress-induced neuroplasticity: (Mal)adaptation to adverse life events in patients with PTSD – A critical overview. Neuroscience 2014; 283:166-77. [DOI: 10.1016/j.neuroscience.2014.08.037] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 08/21/2014] [Accepted: 08/23/2014] [Indexed: 10/24/2022]
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15
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Dong Z, Han H, Li H, Bai Y, Wang W, Tu M, Peng Y, Zhou L, He W, Wu X, Tan T, Liu M, Wu X, Zhou W, Jin W, Zhang S, Sacktor TC, Li T, Song W, Wang YT. Long-term potentiation decay and memory loss are mediated by AMPAR endocytosis. J Clin Invest 2014; 125:234-47. [PMID: 25437879 DOI: 10.1172/jci77888] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 10/30/2014] [Indexed: 01/02/2023] Open
Abstract
Long-term potentiation (LTP) of synaptic strength between hippocampal neurons is associated with learning and memory, and LTP dysfunction is thought to underlie memory loss. LTP can be temporally and mechanistically classified into decaying (early-phase) LTP and nondecaying (late-phase) LTP. While the nondecaying nature of LTP is thought to depend on protein synthesis and contribute to memory maintenance, little is known about the mechanisms and roles of decaying LTP. Here, we demonstrated that inhibiting endocytosis of postsynaptic α-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid receptors (AMPARs) prevents LTP decay, thereby converting it into nondecaying LTP. Conversely, restoration of AMPAR endocytosis by inhibiting protein kinase Mζ (PKMζ) converted nondecaying LTP into decaying LTP. Similarly, inhibition of AMPAR endocytosis prolonged memory retention in normal animals and reduced memory loss in a murine model of Alzheimer's disease. These results strongly suggest that an active process that involves AMPAR endocytosis mediates the decay of LTP and that inhibition of this process can prolong the longevity of LTP as well as memory under both physiological and pathological conditions.
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16
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Eom T, Muslimov IA, Tsokas P, Berardi V, Zhong J, Sacktor TC, Tiedge H. Neuronal BC RNAs cooperate with eIF4B to mediate activity-dependent translational control. ACTA ACUST UNITED AC 2014; 207:237-52. [PMID: 25332164 PMCID: PMC4210447 DOI: 10.1083/jcb.201401005] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Regulatory brain cytoplasmic RNAs cooperate with eukaryotic initiation factor 4B to couple translation to receptor activation in support of long-term plastic changes in neurons. In neurons, translational regulation of gene expression has been implicated in the activity-dependent management of synapto-dendritic protein repertoires. However, the fundamentals of stimulus-modulated translational control in neurons remain poorly understood. Here we describe a mechanism in which regulatory brain cytoplasmic (BC) RNAs cooperate with eukaryotic initiation factor 4B (eIF4B) to control translation in a manner that is responsive to neuronal activity. eIF4B is required for the translation of mRNAs with structured 5′ untranslated regions (UTRs), exemplified here by neuronal protein kinase Mζ (PKMζ) mRNA. Upon neuronal stimulation, synapto-dendritic eIF4B is dephosphorylated at serine 406 in a rapid process that is mediated by protein phosphatase 2A. Such dephosphorylation causes a significant decrease in the binding affinity between eIF4B and BC RNA translational repressors, enabling the factor to engage the 40S small ribosomal subunit for translation initiation. BC RNA translational control, mediated via eIF4B phosphorylation status, couples neuronal activity to translational output, and thus provides a mechanistic basis for long-term plastic changes in nerve cells.
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Affiliation(s)
- Taesun Eom
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
| | - Ilham A Muslimov
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
| | - Panayiotis Tsokas
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203 Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
| | - Valerio Berardi
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
| | - Jun Zhong
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
| | - Todd C Sacktor
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203 Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203 Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
| | - Henri Tiedge
- Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203 Department of Physiology and Pharmacology, Department of Anesthesiology, and Department of Neurology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203
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17
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Insel N, Frankland PW. Mechanism, function, and computation in neural systems. Behav Processes 2014; 117:4-11. [PMID: 25256163 DOI: 10.1016/j.beproc.2014.09.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 08/21/2014] [Accepted: 09/10/2014] [Indexed: 11/25/2022]
Abstract
What constitutes a "mechanism" of behavior? In this tribute to Jerry Hogan we examine how questions of behavioral mechanism can be reframed as causes and consequences of neural circuit activity. Drawing from our work on the hippocampus and the medial prefrontal cortex we discuss the inherent difficulties of characterizing the behavioral functions of circuits that are many synapses away from sensory reception and motor/visceral expression. We briefly review the advantages of reframing a region's functions according to its computations, while also distinguishing those computations from the algorithms by which they are achieved. As an example of how these ideas can be applied, we discuss why the hippocampus and medial prefrontal cortex may have overlapping roles in memory expression in spite of being very different circuits. The present analysis draws inspiration from David Marr, whose framework for describing neural systems can be compared with Aristotle's "causes." This article is part of a Special Issue entitled: In Honor of Jerry Hogan.
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Affiliation(s)
- Nathan Insel
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada M1C1A4; Department of Psychology, University of Toronto, Toronto, ON, Canada M5S3GM.
| | - Paul W Frankland
- Department of Psychology, University of Toronto, Toronto, ON, Canada M5S3GM; Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada M6G1X8; Institute of Medical Science, University of Toronto, Toronto, ON, Canada M5S1A8; Department of Physiology, University of Toronto, Toronto, ON, Canada M5S1A8.
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18
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Ji LL, Tong L, Xu BK, Fu CH, Shu W, Peng JB, Wang ZY. Intra-hippocampal administration of ZIP alleviates depressive and anxiety-like responses in an animal model of posttraumatic stress disorder. Behav Brain Funct 2014; 10:28. [PMID: 25178800 PMCID: PMC4158004 DOI: 10.1186/1744-9081-10-28] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 08/13/2014] [Indexed: 01/20/2023] Open
Abstract
Background Given that impairment of fear extinction has been implicated in the pathogenesis of posttraumatic stress disorder (PTSD), effective pharmacological interventions that facilitate fear extinction may provide alternative strategies to conventional treatment. It is generally accepted that the zeta inhibitory peptide (ZIP), a controversial inhibitor of protein kinase M zeta (PKMζ), could erase certain types of previously established long-term memories. However, it is unclear whether ZIP administration may alleviate PTSD-associated depressive and anxiety-like abnormalities. Methods Here we developed a re-stressed single-prolonged stress (SPS) paradigm, a modified prevalent animal model of PTSD, and assayed the expressions of PKMζ in the hippocampus after SPS procedure. Next, Seven days prior to re-stress, ZIP was injected into the hippocampus, and the depressive and anxiety-like behavior was examined by the subsequent forced swim (FS), open-field and elevated plus maze (EPM) test. Results Rats given ZIP prior to FS exhibited a reduction of immobility time in FS test, and more open arms (OA) entries and longer OA duration in EPM. They also spent longer time in the center of the open field. Conclusions Our results suggested that re-stressed SPS could reproduce behavioral alteration similar to that observed in patients with PTSD, and these behavioral symptoms co-morbid with PTSD could be effectively alleviated by the intro-hippocampal administration of ZIP.
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Affiliation(s)
| | | | | | | | | | | | - Zhen-Yu Wang
- Department of Anatomy, College of Basic Medical Sciences, China Medical University, Shenyang 110001, People's Republic of China.
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19
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Howell KK, Monk BR, Carmack SA, Mrowczynski OD, Clark RE, Anagnostaras SG. Inhibition of PKC disrupts addiction-related memory. Front Behav Neurosci 2014; 8:70. [PMID: 24639635 PMCID: PMC3945752 DOI: 10.3389/fnbeh.2014.00070] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 02/19/2014] [Indexed: 01/20/2023] Open
Abstract
The atypical PKC isoforms, PKMζ and PKCλ have been proposed as integral substrates of long-term memory (LTM). Inhibition of these isoforms has recently been demonstrated to be sufficient for impairing the expression and maintenance of long-term potentiation. Additionally, the pseudosubstrate inhibitor, zeta inhibitory peptide (ZIP), which effectively blocks PKMζ and PKCλ, has previously been shown to disrupt associative memory; very little is known about its effects on pathological nonassociative forms of memory related to addiction. The neural and molecular substrates of memory and addiction have recently been argued to overlap. Here, we used ZIP to disrupt PKMζ and PKCλ activity to examine their role in cocaine sensitization, a nonassociative, addiction-related memory argued to underlie the transition from casual to pathological drug use. We examined the effects of both continuous and acute administration of ZIP. Even a single application of ZIP blocked the development of sensitization; sustained inhibition using osmotic pumps produced an almost complete blockade of sensitization. Further, a single application of ZIP was shown to reduce membrane-bound AMPAR expression. These results demonstrate a novel, critical role for the atypical PKC isoforms in nonassociative memory and cocaine addiction.
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Affiliation(s)
- Kristin K Howell
- Molecular Cognition Laboratory, Department of Psychology, University of California San Diego, La Jolla, CA, USA
| | - Bradley R Monk
- Molecular Cognition Laboratory, Department of Psychology, University of California San Diego, La Jolla, CA, USA
| | - Stephanie A Carmack
- Molecular Cognition Laboratory, Department of Psychology, University of California San Diego, La Jolla, CA, USA
| | - Oliver D Mrowczynski
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Robert E Clark
- Veterans Affairs Medical Center San Diego, CA, USA ; Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - Stephan G Anagnostaras
- Molecular Cognition Laboratory, Department of Psychology, University of California San Diego, La Jolla, CA, USA ; Program in Neurosciences, University of California San Diego, La Jolla, CA, USA
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20
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Takigami S, Sunada H, Lukowiak K, Kuzirian AM, Alkon DL, Sakakibara M. Protein kinase C mediates memory consolidation of taste avoidance conditioning in Lymnaea stagnalis. Neurobiol Learn Mem 2014; 111:9-18. [PMID: 24613854 DOI: 10.1016/j.nlm.2014.02.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 02/05/2014] [Accepted: 02/23/2014] [Indexed: 11/25/2022]
Abstract
In Lymnaea stagnalis, in order to obtain a 10 min short-term memory (STM) of taste avoidance conditioning (TAC) at least 10 paired presentations of a conditioned stimulus (CS), sucrose, and an unconditioned stimulus (US), tactile stimulation to the animal's head, are required. Pre-exposure of snails to the protein kinase C (PKC) α and ε activator bryostatin (Bryo) facilitated STM formation in that only 5 paired CS-US trials were required. Typically 20 paired presentations of the CS-US are required for formation of STM and LTM. However, 20 paired presentations do not result in STM or LTM if snails are pre-incubated with a PKC inhibitor, Ro-32-0432. We also found that LTM lasting longer than 48 h was acquired with Bryo incubation for 45 min even after termination of the conditioning paradigm. These data suggest that activation of the α and ε isozymes of PKC is crucially involved in the formation of LTM and provide further support for a mechanism that has been conserved across the evolution of species ranging from invertebrate molluscs to higher mammals.
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Affiliation(s)
- Satoshi Takigami
- Graduate School of Bioscience, Tokai University, 410-0321 Numazu, Shizuoka, Japan
| | - Hiroshi Sunada
- Hotchkiss Brain Institute, University of Calgary, Faculty of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Ken Lukowiak
- Hotchkiss Brain Institute, University of Calgary, Faculty of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Alan M Kuzirian
- Program in Sensory Physiology & Behavior, Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Daniel L Alkon
- Blanchette Rockefeller Neuroscience Institute, 9601 Medical Center Drive, Rockville, MD 20850-3332, USA
| | - Manabu Sakakibara
- Graduate School of Bioscience, Tokai University, 410-0321 Numazu, Shizuoka, Japan; School of High-Technology for Human Welfare, Tokai University, 410-0321 Numazu, Shizuoka, Japan.
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21
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Callaghan BL, Li S, Richardson R. The elusive engram: what can infantile amnesia tell us about memory? Trends Neurosci 2014; 37:47-53. [DOI: 10.1016/j.tins.2013.10.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 10/24/2013] [Accepted: 10/28/2013] [Indexed: 01/19/2023]
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22
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Hardt O, Nader K, Wang YT. GluA2-dependent AMPA receptor endocytosis and the decay of early and late long-term potentiation: possible mechanisms for forgetting of short- and long-term memories. Philos Trans R Soc Lond B Biol Sci 2013; 369:20130141. [PMID: 24298143 DOI: 10.1098/rstb.2013.0141] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The molecular processes involved in establishing long-term potentiation (LTP) have been characterized well, but the decay of early and late LTP (E-LTP and L-LTP) is poorly understood. We review recent advances in describing the mechanisms involved in maintaining LTP and homeostatic plasticity. We discuss how these phenomena could relate to processes that might underpin the loss of synaptic potentiation over time, and how they might contribute to the forgetting of short-term and long-term memories. We propose that homeostatic downscaling mediates the loss of E-LTP, and that metaplastic parameters determine the decay rate of L-LTP, while both processes require the activity-dependent removal of postsynaptic GluA2-containing AMPA receptors.
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Affiliation(s)
- Oliver Hardt
- Centre for Cognitive and Neural Systems, University of Edinburgh, , Edinburgh, UK
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23
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Vogt-Eisele A, Krüger C, Duning K, Weber D, Spoelgen R, Pitzer C, Plaas C, Eisenhardt G, Meyer A, Vogt G, Krieger M, Handwerker E, Wennmann DO, Weide T, Skryabin BV, Klugmann M, Pavenstädt H, Huentelmann MJ, Kremerskothen J, Schneider A. KIBRA (KIdney/BRAin protein) regulates learning and memory and stabilizes Protein kinase Mζ. J Neurochem 2013; 128:686-700. [PMID: 24117625 DOI: 10.1111/jnc.12480] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Revised: 09/25/2013] [Accepted: 09/30/2013] [Indexed: 01/03/2023]
Abstract
The WWC1 gene has been genetically associated with human episodic memory performance, and its product KIdney/BRAin protein (KIBRA) has been shown to interact with the atypical protein kinase protein kinase M ζ (PKMζ). Although recently challenged, PKMζ remains a candidate postsynaptic regulator of memory maintenance. Here, we show that PKMζ is subject to rapid proteasomal degradation and that KIBRA is both necessary and sufficient to counteract this process, thus stabilizing the kinase and maintaining its function for a prolonged time. We define the binding sequence on KIBRA, a short amino acid motif near the C-terminus. Both hippocampal knock-down of KIBRA in rats and KIBRA knock-out in mice result in decreased learning and memory performance in spatial memory tasks supporting the notion that KIBRA is a player in episodic memory. Interestingly, decreased memory performance is accompanied by decreased PKMζ protein levels. We speculate that the stabilization of synaptic PKMζ protein levels by KIBRA may be one mechanism by which KIBRA acts in memory maintenance. KIBRA/WWC1 has been genetically associated with human episodic memory. KIBRA has been shown to be post-synaptically localized, but its function remained obscure. Here, we show that KIBRA shields PKMζ, a kinase previously linked to memory maintenance, from proteasomal degradation via direct interaction. KIBRA levels in the rodent hippocampus correlate closely both to spatial memory performance in rodents and to PKMζ levels. Our findings support a role for KIBRA in memory, and unveil a novel function for this protein.
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24
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PKCλ is critical in AMPA receptor phosphorylation and synaptic incorporation during LTP. EMBO J 2013; 32:1365-80. [PMID: 23511975 DOI: 10.1038/emboj.2013.60] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 02/13/2013] [Indexed: 01/26/2023] Open
Abstract
Direct phosphorylation of GluA1 by PKC controls α-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA) receptor (AMPAR) incorporation into active synapses during long-term potentiation (LTP). Numerous signalling molecules that involved in AMPAR incorporation have been identified, but the specific PKC isoform(s) participating in GluA1 phosphorylation and the molecule triggering PKC activation remain largely unknown. Here, we report that the atypical isoform of PKC, PKCλ, is a critical molecule that acts downstream of phosphatidylinositol 3-kinase (PI3K) and is essential for LTP expression. PKCλ activation is required for both GluA1 phosphorylation and increased surface expression of AMPARs during LTP. Moreover, p62 interacts with both PKCλ and GluA1 during LTP and may serve as a scaffolding protein to place PKCλ in close proximity to facilitate GluA1 phosphorylation by PKCλ. Thus, we conclude that PKCλ is the critical signalling molecule responsible for GluA1-containing AMPAR phosphorylation and synaptic incorporation at activated synapses during LTP expression.
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25
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Hardt O, Nader K, Nadel L. Decay happens: the role of active forgetting in memory. Trends Cogn Sci 2013; 17:111-20. [DOI: 10.1016/j.tics.2013.01.001] [Citation(s) in RCA: 179] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 01/03/2013] [Accepted: 01/08/2013] [Indexed: 02/06/2023]
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26
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