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Saini V, Kaur T, Kalotra S, Kaur G. The neuroplasticity marker PSA-NCAM: Insights into new therapeutic avenues for promoting neuroregeneration. Pharmacol Res 2020; 160:105186. [DOI: 10.1016/j.phrs.2020.105186] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 08/25/2020] [Accepted: 08/30/2020] [Indexed: 02/06/2023]
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Cooper JM, Halter KA, Prosser RA. Circadian rhythm and sleep-wake systems share the dynamic extracellular synaptic milieu. Neurobiol Sleep Circadian Rhythms 2018; 5:15-36. [PMID: 31236509 PMCID: PMC6584685 DOI: 10.1016/j.nbscr.2018.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 03/06/2018] [Accepted: 04/10/2018] [Indexed: 01/23/2023] Open
Abstract
The mammalian circadian and sleep-wake systems are closely aligned through their coordinated regulation of daily activity patterns. Although they differ in their anatomical organization and physiological processes, they utilize overlapping regulatory mechanisms that include an assortment of proteins and molecules interacting within the extracellular space. These extracellular factors include proteases that interact with soluble proteins, membrane-attached receptors and the extracellular matrix; and cell adhesion molecules that can form complex scaffolds connecting adjacent neurons, astrocytes and their respective intracellular cytoskeletal elements. Astrocytes also participate in the dynamic regulation of both systems through modulating neuronal appositions, the extracellular space and/or through release of gliotransmitters that can further contribute to the extracellular signaling processes. Together, these extracellular elements create a system that integrates rapid neurotransmitter signaling across longer time scales and thereby adjust neuronal signaling to reflect the daily fluctuations fundamental to both systems. Here we review what is known about these extracellular processes, focusing specifically on areas of overlap between the two systems. We also highlight questions that still need to be addressed. Although we know many of the extracellular players, far more research is needed to understand the mechanisms through which they modulate the circadian and sleep-wake systems.
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Key Words
- ADAM, A disintegrin and metalloproteinase
- AMPAR, AMPA receptor
- Astrocytes
- BDNF, brain-derived neurotrophic factor
- BMAL1, Brain and muscle Arnt-like-1 protein
- Bmal1, Brain and muscle Arnt-like-1 gene
- CAM, cell adhesion molecules
- CRY, cryptochrome protein
- Cell adhesion molecules
- Circadian rhythms
- Cry, cryptochrome gene
- DD, dark-dark
- ECM, extracellular matrix
- ECS, extracellular space
- EEG, electroencephalogram
- Endo N, endoneuraminidase N
- Extracellular proteases
- GFAP, glial fibrillary acidic protein
- IL, interleukin
- Ig, immunoglobulin
- LC, locus coeruleus
- LD, light-dark
- LH, lateral hypothalamus
- LRP-1, low density lipoprotein receptor-related protein 1
- LTP, long-term potentiation
- MMP, matrix metalloproteinases
- NCAM, neural cell adhesion molecule protein
- NMDAR, NMDA receptor
- NO, nitric oxide
- NST, nucleus of the solitary tract
- Ncam, neural cell adhesion molecule gene
- Nrl, neuroligin gene
- Nrx, neurexin gene
- P2, purine type 2 receptor
- PAI-1, plasminogen activator inhibitor-1
- PER, period protein
- PPT, peduculopontine tegmental nucleus
- PSA, polysialic acid
- Per, period gene
- REMS, rapid eye movement sleep
- RSD, REM sleep disruption
- SCN, suprachiasmatic nucleus
- SWS, slow wave sleep
- Sleep-wake system
- Suprachiasmatic nucleus
- TNF, tumor necrosis factor
- TTFL, transcriptional-translational negative feedback loop
- VIP, vasoactive intestinal polypeptide
- VLPO, ventrolateral preoptic
- VP, vasopressin
- VTA, ventral tegmental area
- dNlg4, drosophila neuroligin-4 gene
- nNOS, neuronal nitric oxide synthase gene
- nNOS, neuronal nitric oxide synthase protein
- tPA, tissue-type plasminogen activator
- uPA, urokinase-type plasminogen activator
- uPAR, uPA receptor
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Westphal N, Theis T, Loers G, Schachner M, Kleene R. Nuclear fragments of the neural cell adhesion molecule NCAM with or without polysialic acid differentially regulate gene expression. Sci Rep 2017; 7:13631. [PMID: 29051583 PMCID: PMC5648764 DOI: 10.1038/s41598-017-14056-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 10/04/2017] [Indexed: 02/05/2023] Open
Abstract
The neural cell adhesion molecule (NCAM) is the major carrier of polysialic acid (PSA) which modulates NCAM functions of neural cells at the cell surface. In previous studies, we have shown that stimulation of cultured neurons with surrogate NCAM ligands leads to the generation and nuclear import of PSA-lacking and -carrying NCAM fragments. Here, we show that the nuclear import of the PSA-carrying NCAM fragment is mediated by positive cofactor 4 and cofilin, which we identified as novel PSA-binding proteins. In the nucleus, the PSA-carrying NCAM fragment interacts via PSA with PC4 and cofilin, which are involved in RNA polymerase II-dependent transcription. Microarray analysis revealed that the nuclear PSA-carrying and -lacking NCAM fragments affect expression of different genes. By qPCR and immunoblot analysis we verified that the nuclear PSA-carrying NCAM fragment increases mRNA and protein expression of nuclear receptor subfamily 2 group F member 6, whereas the PSA-lacking NCAM fragment increases mRNA and protein expression of low density lipoprotein receptor-related protein 2 and α-synuclein. Differential gene expression evoked by nuclear NCAM fragments without and with PSA indicates that PSA-carrying and -lacking NCAM play different functional roles in the nervous system.
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Affiliation(s)
- Nina Westphal
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251, Hamburg, Germany
| | - Thomas Theis
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251, Hamburg, Germany
| | - Gabriele Loers
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251, Hamburg, Germany
| | - Melitta Schachner
- Center for Neuroscience, Shantou University Medical College, 22 Xin Ling Road, Shantou, Guangdong, 515041, China.
- Keck Center for Collaborative Neuroscience and Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854, USA.
| | - Ralf Kleene
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251, Hamburg, Germany
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Brenachot X, Gautier T, Nédélec E, Deckert V, Laderrière A, Nuzzaci D, Rigault C, Lemoine A, Pénicaud L, Lagrost L, Benani A. Brain Control of Plasma Cholesterol Involves Polysialic Acid Molecules in the Hypothalamus. Front Neurosci 2017; 11:245. [PMID: 28515677 PMCID: PMC5414510 DOI: 10.3389/fnins.2017.00245] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 04/13/2017] [Indexed: 12/31/2022] Open
Abstract
The polysialic acid (PSA) is a large glycan that is added to cell-surface proteins during their post-translational maturation. In the brain, PSA modulates distances between cells and controls the plasticity of the nervous system. In the hypothalamus, PSA is involved in many aspects of energy balance including food intake, osmoregulation, circadian rhythm, and sleep. In this work, we investigated the role of hypothalamic PSA in the regulation of plasma cholesterol levels and distribution. We report that HFD consumption in mice rapidly increased plasma cholesterol, including VLDL, LDL, and HDL-cholesterol. Although plasma VLDL-cholesterol was normalized within the first week, LDL and HDL were still elevated after 2 weeks upon HFD. Importantly, we found that hypothalamic PSA removal aggravated LDL elevation and reduced HDL levels upon HFD. These results indicate that hypothalamic PSA controls plasma lipoprotein profile by circumventing the rise of LDL-to-HDL cholesterol ratio in plasma during overfeeding. Although mechanisms by which hypothalamic PSA controls plasma cholesterol homeostasis remains to be elucidated, these findings also suggest that low level of hypothalamic PSA might be a risk factor for dyslipidemia and cardiovascular diseases.
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Affiliation(s)
- Xavier Brenachot
- AgroSup Dijon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Bourgogne-Franche ComtéDijon, France
| | - Thomas Gautier
- Institut National de la Santé et de la Recherche Médicale LNC, U1231, Université Bourgogne-Franche Comté, LipSTIC LabEx, Fondation de Coopération Scientifique Bourgogne-Franche ComtéDijon, France
| | - Emmanuelle Nédélec
- AgroSup Dijon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Bourgogne-Franche ComtéDijon, France
| | - Valérie Deckert
- Institut National de la Santé et de la Recherche Médicale LNC, U1231, Université Bourgogne-Franche Comté, LipSTIC LabEx, Fondation de Coopération Scientifique Bourgogne-Franche ComtéDijon, France
| | - Amélie Laderrière
- AgroSup Dijon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Bourgogne-Franche ComtéDijon, France
| | - Danaé Nuzzaci
- AgroSup Dijon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Bourgogne-Franche ComtéDijon, France
| | - Caroline Rigault
- AgroSup Dijon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Bourgogne-Franche ComtéDijon, France
| | - Aleth Lemoine
- AgroSup Dijon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Bourgogne-Franche ComtéDijon, France
| | - Luc Pénicaud
- AgroSup Dijon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Bourgogne-Franche ComtéDijon, France
| | - Laurent Lagrost
- Institut National de la Santé et de la Recherche Médicale LNC, U1231, Université Bourgogne-Franche Comté, LipSTIC LabEx, Fondation de Coopération Scientifique Bourgogne-Franche ComtéDijon, France
| | - Alexandre Benani
- AgroSup Dijon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Bourgogne-Franche ComtéDijon, France
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Westphal N, Kleene R, Lutz D, Theis T, Schachner M. Polysialic acid enters the cell nucleus attached to a fragment of the neural cell adhesion molecule NCAM to regulate the circadian rhythm in mouse brain. Mol Cell Neurosci 2016; 74:114-27. [PMID: 27236020 DOI: 10.1016/j.mcn.2016.05.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 05/02/2016] [Accepted: 05/24/2016] [Indexed: 02/05/2023] Open
Abstract
In the mammalian nervous system, the neural cell adhesion molecule NCAM is the major carrier of the glycan polymer polysialic acid (PSA) which confers important functions to NCAM's protein backbone. PSA attached to NCAM contributes not only to cell migration, neuritogenesis, synaptic plasticity, and behavior, but also to regulation of the circadian rhythm by yet unknown molecular mechanisms. Here, we show that a PSA-carrying transmembrane NCAM fragment enters the nucleus after stimulation of cultured neurons with surrogate NCAM ligands, a phenomenon that depends on the circadian rhythm. Enhanced nuclear import of the PSA-carrying NCAM fragment is associated with altered expression of clock-related genes, as shown by analysis of cultured neuronal cells deprived of PSA by specific enzymatic removal. In vivo, levels of nuclear PSA in different mouse brain regions depend on the circadian rhythm and clock-related gene expression in suprachiasmatic nucleus and cerebellum is affected by the presence of PSA-carrying NCAM in the cell nucleus. Our conceptually novel observations reveal that PSA attached to a transmembrane proteolytic NCAM fragment containing part of the extracellular domain enters the cell nucleus, where PSA-carrying NCAM contributes to the regulation of clock-related gene expression and of the circadian rhythm.
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Affiliation(s)
- Nina Westphal
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Ralf Kleene
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - David Lutz
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; Institut für Strukturelle Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Thomas Theis
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Melitta Schachner
- Keck Center for Collaborative Neuroscience and Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ 08854, USA; Center for Neuroscience, Shantou University Medical College, 22 Xin Ling Road, Shantou, Guangdong 515041, China.
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Kronewitter SR, Marginean I, Cox JT, Zhao R, Hagler CD, Shukla AK, Carlson TS, Adkins JN, Camp DG, Moore RJ, Rodland KD, Smith RD. Polysialylated N-glycans identified in human serum through combined developments in sample preparation, separations, and electrospray ionization-mass spectrometry. Anal Chem 2014; 86:8700-10. [PMID: 25118826 PMCID: PMC4151788 DOI: 10.1021/ac501839b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The N-glycan diversity of human serum glycoproteins, i.e., the human blood serum N-glycome, is both complex and constrained by the range of glycan structures potentially synthesizable by human glycosylation enzymes. The known glycome, however, has been further limited by methods of sample preparation, available analytical platforms, e.g., based upon electrospray ionization-mass spectrometry (ESI-MS), and software tools for data analysis. In this report several improvements have been implemented in sample preparation and analysis to extend ESI-MS glycan characterization and to include polysialylated N-glycans. Sample preparation improvements included acidified, microwave-accelerated, PNGase F N-glycan release to promote lactonization, and sodium borohydride reduction, that were both optimized to improve quantitative yields and conserve the number of glycoforms detected. Two-stage desalting (during solid phase extraction and on the analytical column) increased sensitivity by reducing analyte signal division between multiple reducing-end-forms or cation adducts. Online separations were improved by using extended length graphitized carbon columns and adding TFA as an acid modifier to a formic acid/reversed phase gradient, providing additional resolving power and significantly improved desorption of both large and heavily sialylated glycans. To improve MS sensitivity and provide gentler ionization conditions at the source-MS interface, subambient pressure ionization with nanoelectrospray (SPIN) was utilized. When these improved methods are combined together with the Glycomics Quintavariate Informed Quantification (GlyQ-IQ) recently described (Kronewitter et al. Anal. Chem. 2014, 86, 6268-6276), we are able to significantly extend glycan detection sensitivity and provide expanded glycan coverage. We demonstrated the application of these advances in the context of the human serum glycome, and for which our initial observations included the detection of a new class of heavily sialylated N-glycans, including polysialylated N-glycans.
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Affiliation(s)
- Scott R Kronewitter
- Biological Sciences Division, Pacific Northwest National Laboratory , P.O. Box 999, Richland, Washington 99352, United States
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Saaltink DJ, Håvik B, Verissimo CS, Lucassen P, Vreugdenhil E. Doublecortin and doublecortin-like are expressed in overlapping and non-overlapping neuronal cell population: Implications for neurogenesis. J Comp Neurol 2012; 520:2805-23. [DOI: 10.1002/cne.23144] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Haile Y, Berski S, Dräger G, Nobre A, Stummeyer K, Gerardy-Schahn R, Grothe C. The effect of modified polysialic acid based hydrogels on the adhesion and viability of primary neurons and glial cells. Biomaterials 2008; 29:1880-91. [DOI: 10.1016/j.biomaterials.2007.12.030] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Accepted: 12/22/2007] [Indexed: 01/08/2023]
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Acute ethanol modulates glutamatergic and serotonergic phase shifts of the mouse circadian clock in vitro. Neuroscience 2008; 152:837-48. [PMID: 18313227 DOI: 10.1016/j.neuroscience.2007.12.049] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Revised: 12/18/2007] [Accepted: 12/28/2007] [Indexed: 01/05/2023]
Abstract
Alcohol abuse is associated with sleep problems, which are often linked to circadian rhythm disturbances. However, there is no information on the direct effects of ethanol on the mammalian circadian clock. Acute ethanol inhibits glutamate signaling, which is the primary mechanism through which light resets the mammalian clock in the suprachiasmatic nucleus (SCN). Glutamate and light also inhibit circadian clock resetting induced by nonphotic signals, including 5-HT. Thus, we investigated the effects of acute ethanol on both glutamatergic and serotoninergic resetting of the mouse SCN clock in vitro. We show that ethanol dose-dependently inhibits glutamate-induced phase shifts and enhances serotonergic phase shifts. The inhibition of glutamate-induced phase shifts is not affected by excess glutamate, glycine or d-serine, but is prevented by excess brain-derived neurotrophic factor (BDNF). BDNF is known to augment glutamate signaling in the SCN and to be necessary for glutamate/light-induced phase shifts. Thus, ethanol may inhibit glutamate-induced clock resetting at least in part by blocking BDNF enhancement of glutamate signaling. Ethanol enhancement of serotonergic phase shifts is mimicked by treatments that suppress glutamate signaling in the SCN, including antagonists of glutamate receptors, BDNF signaling and nitric oxide synthase. The combined effect of ethanol with these treatments is not additive, suggesting they act through a common pathway. Our data indicate further that the interaction between 5-HT and glutamate in the SCN may occur downstream from nitric oxide synthase activation. Thus, acute ethanol disrupts normal circadian clock phase regulation, which could contribute to the physiological and psychological problems associated with alcohol abuse.
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Polysialic acid in the plasticity of the developing and adult vertebrate nervous system. Nat Rev Neurosci 2008; 9:26-35. [DOI: 10.1038/nrn2285] [Citation(s) in RCA: 479] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lopez-Fernandez MA, Montaron MF, Varea E, Rougon G, Venero C, Abrous DN, Sandi C. Upregulation of polysialylated neural cell adhesion molecule in the dorsal hippocampus after contextual fear conditioning is involved in long-term memory formation. J Neurosci 2007; 27:4552-61. [PMID: 17460068 PMCID: PMC6673006 DOI: 10.1523/jneurosci.0396-07.2007] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2006] [Revised: 03/17/2007] [Accepted: 03/17/2007] [Indexed: 12/20/2022] Open
Abstract
The role of the hippocampus in pavlovian fear conditioning is controversial. Although lesion and pharmacological inactivation studies have suggested a key role for the dorsal hippocampus in contextual fear conditioning, the involvement of the ventral part is still uncertain. Likewise, the debate is open with regard to the putative implication of each hippocampal subdivision in fear conditioning to a discrete conditioned stimulus. We explored the potential existence of dissociations occurring in the dorsal versus ventral hippocampus at the cellular level while dealing with either contextual or cued fear conditioning and focused in a molecular "signature" linked to structural plasticity, the polysialylated form of the neural cell adhesion molecule (PSA-NCAM). We found an upregulation of PSA-NCAM expression in the dorsal (but not ventral) dentate gyrus at 24 h after contextual (but not tone) fear conditioning. Specific removal of PSA through microinfusion of the enzyme endoneuraminidase-N in the dorsal (but not ventral) hippocampus reduced freezing responses to the conditioned context. Therefore, we present evidence for a specific role of PSA-NCAM in the dorsal hippocampus in the plasticity processes occurring during consolidation of the context representation after "standard" contextual fear conditioning. Interestingly, we also found that exposing animals just to the context induced an activation of PSA-NCAM in both dorsal and ventral dentate gyrus. Altogether, these findings highlighting the distinctive occurrence of these neuroplastic processes in the dorsal hippocampus during the standard contextual fear-conditioning task enlighten the ongoing debate about the involvement of these hippocampal subdivisions in pavlovian fear conditioning.
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Affiliation(s)
| | - Marie-Françoise Montaron
- Neurogenesis and Pathophysiology Laboratory, Bordeaux Neuroscience Research Center, Institut National de la Santé et de la Recherche Médicale 862 and University of Bordeaux 2, Bordeaux Cedex 33077, France
| | - Emilio Varea
- Brain Mind Institute, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland
| | - Genevieve Rougon
- Centre National de la Recherche Scientifique Unité Mixte de Recherche 6216, Université de la Méditerranée, Institut de Biologie du Développement de Marseille-Luminy Case 907, Marseille Cedex 13288, France
| | - Cesar Venero
- Psychobiology Department, Universidad Nacional de Educacion a Distancia, 28040 Madrid, Spain, and
| | - Djoher Nora Abrous
- Neurogenesis and Pathophysiology Laboratory, Bordeaux Neuroscience Research Center, Institut National de la Santé et de la Recherche Médicale 862 and University of Bordeaux 2, Bordeaux Cedex 33077, France
| | - Carmen Sandi
- Brain Mind Institute, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland
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Bonfanti L. PSA-NCAM in mammalian structural plasticity and neurogenesis. Prog Neurobiol 2006; 80:129-64. [PMID: 17029752 DOI: 10.1016/j.pneurobio.2006.08.003] [Citation(s) in RCA: 339] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 08/04/2006] [Accepted: 08/21/2006] [Indexed: 12/14/2022]
Abstract
Polysialic acid (PSA) is a linear homopolymer of alpha2-8-N acetylneuraminic acid whose major carrier in vertebrates is the neural cell adhesion molecule (NCAM). PSA serves as a potent negative regulator of cell interactions via its unusual biophysical properties. PSA on NCAM is developmentally regulated thus playing a prominent role in different forms of neural plasticity spanning from embryonic to adult nervous system, including axonal growth, outgrowth and fasciculation, cell migration, synaptic plasticity, activity-induced plasticity, neuronal-glial plasticity, embryonic and adult neurogenesis. The cellular distribution, developmental changes and possible function(s) of PSA-NCAM in the central nervous system of mammals here are reviewed, along with recent findings and theories about the relationships between NCAM protein and PSA as well as the role of different polysialyltransferases. Particular attention is focused on postnatal/adult neurogenesis, an issue which has been deeply investigated in the last decade as an example of persisting structural plasticity with potential implications for brain repair strategies. Adult neurogenic sites, although harbouring all subsequent steps of cell differentiation, from stem cell division to cell replacement, do not faithfully recapitulate development. After birth, they undergo morphological and molecular modifications allowing structural plasticity to adapt to the non-permissive environment of the mature nervous tissue, that are paralled by changes in the expression of PSA-NCAM. The use of PSA-NCAM as a marker for exploring differences in structural plasticity and neurogenesis among mammalian species is also discussed.
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Affiliation(s)
- Luca Bonfanti
- Department of Veterinary Morphophysiology, University of Turin, Via Leonardo da Vinci 44, 10095 Grugliasco, Italy.
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Morin LP, Allen CN. The circadian visual system, 2005. ACTA ACUST UNITED AC 2006; 51:1-60. [PMID: 16337005 DOI: 10.1016/j.brainresrev.2005.08.003] [Citation(s) in RCA: 306] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 07/19/2005] [Accepted: 08/09/2005] [Indexed: 11/17/2022]
Abstract
The primary mammalian circadian clock resides in the suprachiasmatic nucleus (SCN), a recipient of dense retinohypothalamic innervation. In its most basic form, the circadian rhythm system is part of the greater visual system. A secondary component of the circadian visual system is the retinorecipient intergeniculate leaflet (IGL) which has connections to many parts of the brain, including efferents converging on targets of the SCN. The IGL also provides a major input to the SCN, with a third major SCN afferent projection arriving from the median raphe nucleus. The last decade has seen a blossoming of research into the anatomy and function of the visual, geniculohypothalamic and midbrain serotonergic systems modulating circadian rhythmicity in a variety of species. There has also been a substantial and simultaneous elaboration of knowledge about the intrinsic structure of the SCN. Many of the developments have been driven by molecular biological investigation of the circadian clock and the molecular tools are enabling novel understanding of regional function within the SCN. The present discussion is an extension of the material covered by the 1994 review, "The Circadian Visual System."
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Affiliation(s)
- L P Morin
- Department of Psychiatry and Graduate Program in Neuroscience, Stony Brook University, Stony Brook, NY 11794, USA.
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Intrinsic role of polysialylated neural cell adhesion molecule in photic phase resetting of the Mammalian circadian clock. J Neurosci 2003. [PMID: 12533624 DOI: 10.1523/jneurosci.23-02-00652.2003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The suprachiasmatic nuclei (SCN), the location of the mammalian circadian clock, are one of the few adult brain regions that express the highly polysialylated form of neural cell adhesion molecule (PSA-NCAM). A role for the polysialic acid (PSA) component of PSA-NCAM, which is known to promote tissue plasticity, has been reported for photic entrainment of circadian rhythmicity in vivo. The in vivo results, however, do not discriminate between PSA acting upstream or downstream of the glutamatergic synapses that convey photic information to the SCN. To address this key issue, we exploited an in vitro rat brain slice preparation that retains robust circadian function. As in the intact SCN, PSA levels in the isolated SCN are rhythmic, with higher levels during the early subjective day and lower levels during subjective night. Importantly, bath application of glutamate to SCN slices rapidly and transiently increases PSA levels during both the subjective day and night. Pretreating the slices with endoneuraminidase, which selectively removes PSA from NCAM and thereby prevents this increase, abolishes glutamate- and optic chiasm stimulation-induced phase delays of the SCN circadian neuronal activity rhythm. These results support the hypothesis that PSA expression in the SCN is controlled by both the circadian clock and photic input to the clock and that expression of PSA in the SCN is critical for photic-like phase shifts of the clock. Together, these results establish that such actions of PSA are manifested downstream from presynaptic retinohypothalamic terminals and therefore are intrinsic to the SCN itself.
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