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Fesce R. Old innovations and shifted paradigms in cellular neuroscience. Front Cell Neurosci 2024; 18:1460219. [PMID: 39234031 PMCID: PMC11371623 DOI: 10.3389/fncel.2024.1460219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2024] [Accepted: 08/06/2024] [Indexed: 09/06/2024] Open
Abstract
Once upon a time the statistics of quantal release were fashionable: "n" available vesicles (fusion sites), each with probability "p" of releasing a quantum. The story was not so simple, a nice paradigm to be abandoned. Biophysicists, experimenting with "black films," explained the astonishing rapidity of spike-induced release: calcium can trigger the fusion of lipidic vesicles with a lipid bilayer, by masking the negative charges of the membranes. The idea passed away, buried by the discovery of NSF, SNAPs, SNARE proteins and synaptotagmin, Munc, RIM, complexin. Electrophysiology used to be a field for few adepts. Then came patch clamp, and multielectrode arrays and everybody became electrophysiologists. Now, optogenetics have blossomed, and the whole field has changed again. Nice surprise for me, when Alvarez de Toledo demonstrated that release of transmitters could occur through the transient opening of a pore between the vesicle and the plasma-membrane, no collapse of the vesicle in the membrane needed: my mentor Bruno Ceccarelli had cherished this idea ("kiss and run") and tried to prove it for 20 years. The most impressive developments have probably regarded IT, computers and all their applications; machine learning, AI, and the truly spectacular innovations in brain imaging, especially functional ones, have transformed cognitive neurosciences into a new extraordinarily prolific field, and certainly let us imagine that we may finally understand what is going on in our brains. Cellular neuroscience, on the other hand, though the large public has been much less aware of the incredible amount of information the scientific community has acquired on the cellular aspects of neuronal function, may indeed help us to eventually understand the mechanistic detail of how the brain work. But this is no more in the past, this is the future.
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Affiliation(s)
- Riccardo Fesce
- Department of Biomedical Sciences, Humanitas University Medical School, Pieve Emanuele, Italy
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2
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The mechanisms of chromogranin B-regulated Cl- homeostasis. Biochem Soc Trans 2022; 50:1659-1672. [PMID: 36511243 DOI: 10.1042/bst20220435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/25/2022] [Accepted: 12/01/2022] [Indexed: 12/15/2022]
Abstract
Chloride is the most abundant inorganic anions in almost all cells and in human circulation systems. Its homeostasis is therefore important for systems physiology and normal cellular activities. This topic has been extensively studied with chloride loaders and extruders expressed in both cell surfaces and intracellular membranes. With the newly discovered, large-conductance, highly selective Cl- channel formed by membrane-bound chromogranin B (CHGB), which differs from all other known anion channels of conventional transmembrane topology, and is distributed in plasma membranes, endomembrane systems, endosomal, and endolysosomal compartments in cells expressing it, we will discuss the potential physiological importance of the CHGB channels to Cl- homeostasis, cellular excitability and volume control, and cation uptake or release at the cellular and subcellular levels. These considerations and CHGB's association with human diseases make the CHGB channel a possible druggable target for future molecular therapeutics.
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3
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Parker SE, Bellingham MC, Woodruff TM. Complement drives circuit modulation in the adult brain. Prog Neurobiol 2022; 214:102282. [DOI: 10.1016/j.pneurobio.2022.102282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/24/2022] [Accepted: 05/02/2022] [Indexed: 11/16/2022]
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4
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Zhang CM, Imoto Y, Hikima T, Inoue T. Structural flexibility of the tetanus neurotoxin revealed by crystallographic and solution scattering analyses. JOURNAL OF STRUCTURAL BIOLOGY-X 2021; 5:100045. [PMID: 33598655 PMCID: PMC7868712 DOI: 10.1016/j.yjsbx.2021.100045] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Although the tetanus neurotoxin (TeNT) delivers its protease domain (LC) across the synaptic vesicle lumen into the cytosol via its receptor binding domain (HC) and translocation domain (HN), the molecular mechanism coordinating this membrane translocation remains unresolved. Here, we report the high-resolution crystal structures of full-length reduced TeNT (rTeNT, 2.3 Å), TeNT isolated HN (TeNT/iHN, 2.3 Å), TeNT isolated HC (TeNT/iHC, 1.5 Å), together with the solution structures of TeNT/iHN and beltless TeNT/iHN (TeNT/blHN). TeNT undergoes significant domains rotation of the HN and LC were demonstrated by structural comparison of rTeNT and non-reduced-TeNT (nrTeNT). A linker loop connects the HN and HC is essential for the self-domain rotation of TeNT. The TeNT-specific C869-C1093 disulfide bond is sensitive to the redox environment and its disruption provides linker loop flexibility, which enables domain arrangement of rTeNT distinct from that of nrTeNT. Furthermore, the mobility of C869 in the linker loop and the sensitivity to redox condition of C1093 were confirmed by crystal structure analysis of TeNT/iHC. On the other hand, the structural flexibility of HN was investigated by crystallographic and solution scattering analyses. It was found that the region (residues 698-769), which follows the translocation region had remarkable change in TeNT/iHN. Besides, the so-called belt region has a high propensity to swing around the upper half of TeNT/iHN at acidic pH. It provides the first overview of the dynamics of the Belt in solution. These newly obtained structural information that shed light on the transmembrane mechanism of TeNT.
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Affiliation(s)
- Chun-Ming Zhang
- Graduate School of Pharmaceutical Science, Osaka University, Suita, 565-0871 Osaka, Japan
| | - Yoshihiro Imoto
- Graduate School of Pharmaceutical Science, Osaka University, Suita, 565-0871 Osaka, Japan
| | - Takaaki Hikima
- Advanced Photon Technology Division, RIKEN SPring-8 Center, Sayo-gun, 679-6148, Japan
| | - Tsuyoshi Inoue
- Graduate School of Pharmaceutical Science, Osaka University, Suita, 565-0871 Osaka, Japan
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5
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Chand S, Jo A, Vellichirammal NN, Gowen A, Guda C, Schaal V, Odegaard K, Lee H, Pendyala G, Yelamanchili SV. Comprehensive Characterization of Nanosized Extracellular Vesicles from Central and Peripheral Organs : Implications for Preclinical and Clinical Applications. ACS APPLIED NANO MATERIALS 2020; 3:8906-8919. [PMID: 33385108 PMCID: PMC7771629 DOI: 10.1021/acsanm.0c01654] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Extracellular vesicles (EV) are nano-sized vesicles that have been garnering a lot of attention for their valuable role as potential diagnostic markers and therapeutic vehicles for a plethora of pathologies. Whilst EV markers from biofluids such as plasma, serum, urine, cerebrospinal fluid and in vitro cell culture based platforms have been extensively studied, a significant knowledge gap that remains is the characterization of specific organ derived EVs (ODE). Here, we present a standardized protocol for isolation and characterization of purified EV isolated from brain, heart, lung, kidney and liver from rat and postmortem human tissue. Next, using quantitative mass spectrometry based proteomics, we characterized the respective tissue EV proteomes that identified synaptophysin (SYP), caveolin-3 (CAV3), solute carrier family 22 member 2 (SLC22A2), surfactant protein B (SP-B), and fatty acid-binding protein 1 (FABP1) as potential markers for the brain, heart, kidney, lung, and liver-EV, respectively. These respective tissue specific markers were further validated using both immunoblotting and a nanoplasmonic platform- single EV imaging analysis in the two species. To summarize, our study for the first time using traditional biochemical and high precision technology platforms provide a valuable proof of concept approach in defining specific ODE markers which further could be developed as potential therapeutic candidates for respective end-organ associated pathologies.
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Affiliation(s)
- Subhash Chand
- Department of Anesthesiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Ala Jo
- Center for Systems Biology, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Radiology, Massachusetts General Hospital, Boston, MA, 02114, USA
| | | | - Austin Gowen
- Department of Anesthesiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Chittibabu Guda
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Victoria Schaal
- Department of Anesthesiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Katherine Odegaard
- Department of Anesthesiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Hakho Lee
- Center for Systems Biology, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Radiology, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Gurudutt Pendyala
- Department of Anesthesiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Sowmya V. Yelamanchili
- Department of Anesthesiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Address for correspondence: Dr. Sowmya V. Yelamanchili, Lied Transplant Center 10736, 984455 Nebraska Medical Center, Omaha, NE 68198-4455, Telephone: 402-559-5348,
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Cheng R, Xu T, Zhang Y, Wang F, Zhao L, Jiang Y, He F. Lactobacillus rhamnosus GG and Bifidobacterium bifidum TMC3115 Can Affect Development of Hippocampal Neurons Cultured In Vitro in a Strain-Dependent Manner. Probiotics Antimicrob Proteins 2020; 12:589-599. [PMID: 31286435 DOI: 10.1007/s12602-019-09571-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
This study examined whether Lactobacillus rhamnosus GG (LGG) and Bifidobacterium bifidum TMC3115 (TMC3115) could morphologically or physiologically influence hippocampal neuronal development in vitro. Hippocampal neurons cultured in vitro were exposed to live or heat-inactivated LGG or TMC3115 for either 6 or 24 h. Neuronal morphological changes and drebrin (DRB) and synaptophysin (SYP) protein levels were monitored using immunofluorescence. And the levels of DRB, SYP, and brain-derived neurotrophic factor (BDNF), and cAMP-response element binding protein (CREB) mRNA were detected using RT-PCR. The BDNF, CREB, and phosphorylated-CREB (P-CREB) protein levels were detected by extraction-enzyme-linked immunosorbent assay (ELISA) or Western blot assays. Heat-inactivated LGG and TMC3115 could enhance neuron viability, DRB and SYP protein levels, and BDNF mRNA level were significantly altered after exposure to the tested bacteria with 6 h or 24 h. There were no significant differences in neuronal morphology or DRB, SYP, or CREB mRNA levels among the groups following bacterial exposure. However, following exposure of live TMC3115 for 24 h, the neuronal BDNF and P-CREB protein levels were both significantly up-regulated as detected by western blot assays. These results demonstrated that LGG and TMC3115 could affect neuronal viability, along with hippocampal synaptic and functional development, in a strain-dependent manner, which may also be closely associated with the physiological and culture conditions of each strain. Up-regulated P-CREB may be one of the underlying mechanisms by which the bacteria, especially neurons following exposure of live TMC3115 for 24 h, are able to regulate neuronal BDNF protein production.
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Affiliation(s)
- Ruyue Cheng
- Department of Nutrition, Food Hygiene and Toxicology, West China School of Public Health and West China Fourth Hospital, and Healthy Food Evaluation Research Center, Sichuan University, No. 16, 3rd section, South Renmin Road, Wuhou District, Chengdu, 610041, Sichuan, People's Republic of China
- Department of Nutrition and Food Hygiene, Institute of Environmental and Operational Medicine, Tianjin, 300050, People's Republic of China
| | - Tong Xu
- Department of Nutrition and Food Hygiene, Institute of Environmental and Operational Medicine, Tianjin, 300050, People's Republic of China
| | - Yujie Zhang
- Department of Nutrition, Food Hygiene and Toxicology, West China School of Public Health and West China Fourth Hospital, and Healthy Food Evaluation Research Center, Sichuan University, No. 16, 3rd section, South Renmin Road, Wuhou District, Chengdu, 610041, Sichuan, People's Republic of China
- Department of Nutrition and Food Hygiene, Institute of Environmental and Operational Medicine, Tianjin, 300050, People's Republic of China
| | - Feng Wang
- Department of Nutrition and Food Hygiene, Institute of Environmental and Operational Medicine, Tianjin, 300050, People's Republic of China
| | - Linsen Zhao
- Hebei Inatural Biotech Co. Ltd., Shijiazhuang, 050000, Hebei, People's Republic of China
| | - Yugang Jiang
- Department of Nutrition and Food Hygiene, Institute of Environmental and Operational Medicine, Tianjin, 300050, People's Republic of China.
| | - Fang He
- Department of Nutrition, Food Hygiene and Toxicology, West China School of Public Health and West China Fourth Hospital, and Healthy Food Evaluation Research Center, Sichuan University, No. 16, 3rd section, South Renmin Road, Wuhou District, Chengdu, 610041, Sichuan, People's Republic of China.
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7
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Ranjbari E, Majdi S, Ewing A. Analytical Techniques: Shedding Light upon Nanometer-Sized Secretory Vesicles. TRENDS IN CHEMISTRY 2019. [DOI: 10.1016/j.trechm.2019.02.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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8
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Costa AS, Guerini FR, Arosio B, Galimberti D, Zanzottera M, Bianchi A, Nemni R, Clerici M. SNARE Complex Polymorphisms Associate with Alterations of Visual Selective Attention in Alzheimer’s Disease. J Alzheimers Dis 2019; 69:179-188. [DOI: 10.3233/jad-190147] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
| | | | - Beatrice Arosio
- Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Geriatric Unit, Milan, Italy
- Department of Medical Sciences and Community Health, University of Milan, Milan, Italy
| | - Daniela Galimberti
- Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Neurodegenerative Diseases Unit, Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milano, Milano, Italy
| | | | - Anna Bianchi
- IRCCS Fondazione Don Carlo Gnocchi, Milan, Italy
| | - Raffaello Nemni
- IRCCS Fondazione Don Carlo Gnocchi, Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milano, Milano, Italy
| | - Mario Clerici
- IRCCS Fondazione Don Carlo Gnocchi, Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milano, Milano, Italy
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9
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Rudolf R, Khan MM, Witzemann V. Motor Endplate-Anatomical, Functional, and Molecular Concepts in the Historical Perspective. Cells 2019; 8:E387. [PMID: 31035624 PMCID: PMC6562597 DOI: 10.3390/cells8050387] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 04/20/2019] [Accepted: 04/25/2019] [Indexed: 11/17/2022] Open
Abstract
By mediating voluntary muscle movement, vertebrate neuromuscular junctions (NMJ) play an extraordinarily important role in physiology. While the significance of the nerve-muscle connectivity was already conceived almost 2000 years back, the precise cell and molecular biology of the NMJ have been revealed in a series of fascinating research activities that started around 180 years ago and that continues. In all this time, NMJ research has led to fundamentally new concepts of cell biology, and has triggered groundbreaking advancements in technologies. This review tries to sketch major lines of thought and concepts on NMJ in their historical perspective, in particular with respect to anatomy, function, and molecular components. Furthermore, along these lines, it emphasizes the mutual benefit between science and technology, where one drives the other. Finally, we speculate on potential major future directions for studies on NMJ in these fields.
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Affiliation(s)
- Rüdiger Rudolf
- Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, 68163 Mannheim, Germany.
- Interdisciplinary Center for Neuroscience, Heidelberg University, 69120 Heidelberg, Germany.
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Muzamil Majid Khan
- Cell Biology and Biophysics, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
| | - Veit Witzemann
- Max Planck Institute for Medical Research, 69120 Heidelberg, Germany.
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10
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Abstract
This review summarizes current knowledge of synaptic proteins that are central to synaptic vesicle fusion in presynaptic active zones, including SNAREs (soluble N-ethylmaleimide sensitive factor attachment protein receptors), synaptotagmin, complexin, Munc18 (mammalian uncoordinated-18), and Munc13 (mammalian uncoordinated-13), and highlights recent insights in the cooperation of these proteins for neurotransmitter release. Structural and functional studies of the synaptic fusion machinery suggest new molecular models of synaptic vesicle priming and Ca2+-triggered fusion. These studies will be a stepping-stone toward answering the question of how the synaptic vesicle fusion machinery achieves such high speed and sensitivity.
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Affiliation(s)
- Axel T Brunger
- Department of Molecular and Cellular Physiology, Department of Neurology and Neurological Sciences, Department of Structural Biology, Department of Photon Science, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA;
| | - Ucheor B Choi
- Department of Molecular and Cellular Physiology, Department of Neurology and Neurological Sciences, Department of Structural Biology, Department of Photon Science, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA;
| | - Ying Lai
- Department of Molecular and Cellular Physiology, Department of Neurology and Neurological Sciences, Department of Structural Biology, Department of Photon Science, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA;
| | - Jeremy Leitz
- Department of Molecular and Cellular Physiology, Department of Neurology and Neurological Sciences, Department of Structural Biology, Department of Photon Science, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA;
| | - Qiangjun Zhou
- Department of Molecular and Cellular Physiology, Department of Neurology and Neurological Sciences, Department of Structural Biology, Department of Photon Science, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA;
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11
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Molino D, Nascimbeni AC, Giordano F, Codogno P, Morel E. ER-driven membrane contact sites: Evolutionary conserved machineries for stress response and autophagy regulation? Commun Integr Biol 2017; 10:e1401699. [PMID: 29259731 PMCID: PMC5731517 DOI: 10.1080/19420889.2017.1401699] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 10/20/2017] [Accepted: 10/31/2017] [Indexed: 10/26/2022] Open
Abstract
Endoplasmic Reticulum (ER), spreading in the whole cell cytoplasm, is a central player in eukaryotic cell homeostasis, from plants to mammals. Beside crucial functions, such as membrane lipids and proteins synthesis and outward transport, the ER is able to connect to virtually every endomembrane compartment by specific tethering molecular machineries, which enables the establishment of membrane-membrane contact sites. ER-mitochondria contact sites have been shown to be involved in autophagosome biogenesis, the main organelle of the autophagy degradation pathway. More recently we demonstrated that also ER-plasma membrane contact sites are sites for autophagosomes assembly, suggesting that more generally ER-organelles contacts are involved in autophagy and organelle biogenesis. Here we aim to discuss the functioning of ER-driven contact sites in mammals and plants and more in particular emphasize on their recently highlighted function in autophagy to finally conclude on some key questions that may be useful for further research in the field.
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Affiliation(s)
- Diana Molino
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR.,Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Anna Chiara Nascimbeni
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR.,Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Francesca Giordano
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Patrice Codogno
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR.,Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Etienne Morel
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR.,Université Paris Descartes-Sorbonne Paris Cité, Paris, France
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12
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Huntingtin-associated protein-1 (HAP1) regulates endocytosis and interacts with multiple trafficking-related proteins. Cell Signal 2017; 35:176-187. [DOI: 10.1016/j.cellsig.2017.02.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 02/16/2017] [Accepted: 02/28/2017] [Indexed: 12/24/2022]
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13
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Gilles JF, Dos Santos M, Boudier T, Bolte S, Heck N. DiAna, an ImageJ tool for object-based 3D co-localization and distance analysis. Methods 2017; 115:55-64. [DOI: 10.1016/j.ymeth.2016.11.016] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 11/22/2016] [Accepted: 11/22/2016] [Indexed: 12/16/2022] Open
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14
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Abstract
Neurotransmitters are normally released from neurons via calcium-dependent exocytosis of synaptic vesicles. However, after blockade of vesicular release by removal of calcium, or treatment with tetanus toxin, neurotransmitter release can still occur. In the case of GABA, nonvesicular release results from reversal of its uptake transporter, found on both neurons and glia. These GABA transporters are sodium-dependent and electrogenic, and therefore can be induced to operate in reverse by cell depolarization or by breakdown of the sodium gradient. Although demonstrated biochemically, less is known about whether this form of release occurs in vivo or whether it results in electrophysiological effects. Because conditions that favor reversal of the GABA transporter occur during high-frequency firing, nonvesicular GABA release may occur with excessive neuronal activity, such as during seizures. NEUROSCIENTIST 3:151-157, 1997
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15
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The impacts of diabetes in pregnancy on hippocampal synaptogenesis in rat neonates. Neuroscience 2016; 318:122-33. [DOI: 10.1016/j.neuroscience.2016.01.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 12/28/2015] [Accepted: 01/11/2016] [Indexed: 11/21/2022]
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16
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Abstract
To create a presynaptic terminal, molecular signaling events must be orchestrated across a number of subcellular compartments. In the soma, presynaptic proteins need to be synthesized, packaged together, and attached to microtubule motors for shipment through the axon. Within the axon, transport of presynaptic packages is regulated to ensure that developing synapses receive an adequate supply of components. At individual axonal sites, extracellular interactions must be translated into intracellular signals that can incorporate mobile transport vesicles into the nascent presynaptic terminal. Even once the initial recruitment process is complete, the components and subsequent functionality of presynaptic terminals need to constantly be remodeled. Perhaps most remarkably, all of these processes need to be coordinated in space and time. In this review, we discuss how these dynamic cellular processes occur in neurons of the central nervous system in order to generate presynaptic terminals in the brain.
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Affiliation(s)
- Luke A D Bury
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Shasta L Sabo
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH, USA Department of Neuroscience, Case Western Reserve University School of Medicine, Cleveland, OH, USA
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17
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18
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Südhof TC. Der molekulare Mechanismus der Neurotransmitterfreisetzung und Nervenzell-Synapsen (Nobel-Aufsatz). Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201406359] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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19
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Südhof TC. The molecular machinery of neurotransmitter release (Nobel lecture). Angew Chem Int Ed Engl 2014; 53:12696-717. [PMID: 25339369 DOI: 10.1002/anie.201406359] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Indexed: 12/18/2022]
Abstract
The most important property of synaptic transmission is its speed, which is crucial for the overall workings of the brain. In his Nobel Lecture, T. C. Südhof explains how the synaptic vesicle and the plasma membrane undergo rapid fusion during neurotransmitter release and how this process is spatially organized, such that opening of Ca(2+) -channels allows rapid translation of the entering Ca(2+) signal into a fusion event.
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Affiliation(s)
- Thomas C Südhof
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Lorry Lokey SIM1 Building 07-535 Room G1021, 265 Campus Drive, Stanford University School of Medicine, CA 94305 (USA)
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20
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Sun J. A legend of the SNARE complex and synaptotagmin-the insight into synaptic transmission. SCIENCE CHINA. LIFE SCIENCES 2013; 56:1150-1153. [PMID: 24222513 DOI: 10.1007/s11427-013-4572-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 11/04/2013] [Indexed: 06/02/2023]
Affiliation(s)
- JianYuan Sun
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China,
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21
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Kelsch W, Sim S, Lois C. Increasing heterogeneity in the organization of synaptic inputs of mature olfactory bulb neurons generated in newborn rats. J Comp Neurol 2012; 520:1327-38. [PMID: 22102059 DOI: 10.1002/cne.22799] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
New neurons are added into the mammalian olfactory bulb throughout life, but it remains unknown whether the properties of new neurons generated in newborn animals differ from those added during adulthood. We compared the densities of glutamatergic synapses of granule cells (GCs) generated in newborn and adult rats over extended periods of time. We observed that, whereas adult-born GCs maintained stable cell-to-cell variability of synaptic densities soon after they integrated into the circuit, cell-to-cell variability of synaptic densities of neonatal-born GCs increased months after their integration. We also investigated whether the synaptic reorganization induced by sensory deprivation occurred differently in mature neonatal- and adult-born GCs. Sensory deprivation after new GCs had differentiated induced more pronounced changes in the synaptic densities of neonatal-born GCs than in adult-born GCs. These observations suggest that the synapses of mature neonatal-born GCs retain a higher degree of malleability in response to changes in neuronal activity than adult-born GCs.
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Affiliation(s)
- Wolfgang Kelsch
- Department of Clinical Neurobiology, University Heidelberg, D-69120 Heidelberg, Germany
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22
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Compensation of depleted neuronal subsets by new neurons in a local area of the adult olfactory bulb. J Neurosci 2011; 31:10540-57. [PMID: 21775599 DOI: 10.1523/jneurosci.1285-11.2011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
In the olfactory bulb (OB), loss of preexisting granule cells (GCs) and incorporation of adult-born new GCs continues throughout life. GCs consist of distinct subsets. Here, we examined whether the loss and incorporation of GC subsets are coordinated in the OB. We classified GCs into mGluR2-expressing and -negative subsets and selectively ablated mGluR2-expressing GCs in a local area of the OB with immunotoxin-mediated cell ablation method. The density of mGluR2-expressing GCs showed considerable recovery within several weeks after the ablation. During recovery, an mGluR2-expressing new GC subset was preferentially incorporated over an mGluR2-negative new GC subset in the area of ablation, whereas the preferential incorporation was not observed in the intact area. The area-specific preferential incorporation of mGluR2-expressing new GCs occurred for BrdU analog- and retrovirus-labeled adult-born cells as well as for neonate-derived transplanted cells. The mGluR2-expressing new GCs in the ablated area were synaptically incorporated into the local bulbar circuit. The spine size of mGluR2-expressing new GCs in the ablated area was larger than that of those in the intact area. In contrast, mGluR2-negative new GCs did not show ablated area-specific spine enlargement. These results indicate that local OB areas have a mechanism to coordinate the loss and incorporation of GC subsets by compensatory incorporation of new GC subsets, which involves subset-specific cellular incorporation and subset-specific regulation of spine size.
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Dahlen JE, Jimenez DA, Gerkin RC, Urban NN. Morphological analysis of activity-reduced adult-born neurons in the mouse olfactory bulb. Front Neurosci 2011; 5:66. [PMID: 21602912 PMCID: PMC3092085 DOI: 10.3389/fnins.2011.00066] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 04/27/2011] [Indexed: 12/30/2022] Open
Abstract
Adult-born neurons (ABNs) are added to the olfactory bulb (OB) throughout life in rodents. While many factors have been identified as regulating the survival and integration of ABNs into existing circuitry, the understanding of how these factors affect ABN morphology and connectivity is limited. Here we compare how cell intrinsic [small interfering RNA (siRNA) knock-down of voltage gated sodium channels NaV1.1–1.3] and circuit level (naris occlusion) reductions in activity affect ABN morphology during integration into the OB. We found that both manipulations reduce the number of dendritic spines (and thus likely the number of reciprocal synaptic connections) formed with the surrounding circuitry and inhibited dendritic ramification of ABNs. Further, we identified regions of ABN apical dendrites where the largest and most significant decreases occur following siRNA knock-down or naris occlusion. In siRNA knock-down cells, reduction of spines is observed in proximal regions of the apical dendrite. This suggests that distal regions of the dendrite may remain active independent of NaV1.1–1.3 channel expression, perhaps facilitated by activation of T-type calcium channels and NMDA receptors. By contrast, circuit level reduction of activity by naris occlusion resulted in a global depression of spine number. Together, these results indicate that ABNs retain the ability to develop their typical overall morphological features regardless of experienced activity, and activity modulates the number and location of formed connections.
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Affiliation(s)
- Jeffrey E Dahlen
- Department of Biological Sciences, Carnegie Mellon University Pittsburgh, PA, USA
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Abstract
Although the lifelong addition of new neurons to the olfactory bulb and dentate gyrus of mammalian brains is by now an accepted fact, the function of adult-generated neurons still largely remains a mystery. The ability of new neurons to form synapses with preexisting neurons without disrupting circuit function is central to the hypothesized role of adult neurogenesis as a substrate for learning and memory. With the development of several new genetic labeling and imaging techniques, the study of synapse development and integration of these new neurons into mature circuits both in vitro and in vivo is rapidly advancing our insight into their structural plasticity. Investigators' observation of synaptogenesis occurring in the adult brain is beginning to shed light on the flexibility that adult neurogenesis offers to mature circuits and the potential contribution of the transient plasticity that new neurons provide toward circuit refinement and adaptation to changing environmental demands.
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Affiliation(s)
- Wolfgang Kelsch
- Picower Institute of Learning and Memory, Department of Biology and Brain, Massachussetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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Kim HJ, Casadesus G. Estrogen-mediated effects on cognition and synaptic plasticity: what do estrogen receptor knockout models tell us? Biochim Biophys Acta Gen Subj 2010; 1800:1090-3. [PMID: 20470868 DOI: 10.1016/j.bbagen.2010.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Revised: 04/05/2010] [Accepted: 05/04/2010] [Indexed: 10/19/2022]
Abstract
A plethora of evidence supports a beneficial role of estrogen in the brain. However, while these effects are hypothesized to be driven via the two main forms of estrogen receptors (ERα and ERß), the mechanism through which these receptors mediate estrogen's effects on cognition and plasticity remain unclear. Estrogen receptors are heterogeneously expressed in many cognition sensitive regions of the brain, have the ability to dimerize and heterodimerize, and are localized to both neurons and glia. In addition, while many of the known actions of estrogen through their receptor are mediated via the classical genomic regulatory mechanism of gene transcription, rapid non-genomic action of estrogens are also gaining relevance. These complex events make the mechanistic understanding of estrogen effects challenging. The development of transgenic estrogen receptor knockout mouse models has provided some much needed insight on the role of these receptors in mediating estrogen effects on cognition and synaptic plasticity. This review provides an overview of estrogen receptors in the brain and an update of knowledge gained from transgenic knockout models on cognition and synaptic plasticity.
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Affiliation(s)
- Hyun Jin Kim
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA
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Lee H, Brecha NC. Immunocytochemical evidence for SNARE protein-dependent transmitter release from guinea pig horizontal cells. Eur J Neurosci 2010; 31:1388-401. [PMID: 20384779 DOI: 10.1111/j.1460-9568.2010.07181.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Horizontal cells are lateral interneurons that participate in visual processing in the outer retina but the cellular mechanisms underlying transmitter release from these cells are not fully understood. In non-mammalian horizontal cells, GABA release has been shown to occur by a non-vesicular mechanism. However, recent evidence in mammalian horizontal cells favors a vesicular mechanism as they lack plasmalemmal GABA transporters and some soluble NSF attachment protein receptor (SNARE) core proteins have been identified in rodent horizontal cells. Moreover, immunoreactivity for GABA and the molecular machinery to synthesize GABA have been found in guinea pig horizontal cells, suggesting that if components of the SNARE complex are expressed they could contribute to the vesicular release of GABA. In this study we investigated whether these vesicular and synaptic proteins are expressed by guinea pig horizontal cells using immunohistochemistry with well-characterized antibodies to evaluate their cellular distribution. Components of synaptic vesicles including vesicular GABA transporter, synapsin I and synaptic vesicle protein 2A were localized to horizontal cell processes and endings, along with the SNARE core complex proteins, syntaxin-1a, syntaxin-4 and synaptosomal-associated protein 25 (SNAP-25). Complexin I/II, a cytosolic protein that stabilizes the activated SNARE fusion core, strongly immunostained horizontal cell soma and processes. In addition, the vesicular Ca(2+)-sensor, synaptotagmin-2, which is essential for Ca(2+)-mediated vesicular release, was also localized to horizontal cell processes and somata. These morphological findings from guinea pig horizontal cells suggest that mammalian horizontal cells have the capacity to utilize a regulated Ca(2+)-dependent vesicular pathway to release neurotransmitter, and that this mechanism may be shared among many mammalian species.
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Affiliation(s)
- Helen Lee
- Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California at Los Angeles, Los Angeles, CA 90095-1763, USA.
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Rekart JL, Routtenberg A. Overexpression of GAP-43 reveals unexpected properties of hippocampal mossy fibers. Hippocampus 2010; 20:46-57. [PMID: 19650124 DOI: 10.1002/hipo.20668] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The mossy fiber (MF) system targets the apical dendrites of CA3 pyramidal cells in the stratum lucidum (SL). In mice overexpressing the growth-associated protein GAP-43 there is an apparent ectopic growth of these MFs into the stratum oriens (SO) targeting the basal dendrites of these same pyramidal cells (Aigner et al. (1995) Cell 83:269-278). This is the first evidence to our knowledge that links increased GAP-43 expression with growth of central axons. Here we studied the Aigner et al. transgenic mice but were unable to confirm such growth into SO. However, using quantitative methods we did observe enhanced growth within the regions normally targeted by MFs, for example, the SL in the CA3a region. These contrasting results led us to study MFs with double-immunostaining using an immunohistochemical marker for MFs, the zinc transporter, ZnT3, to visualize the colocalization of transgenic GAP-43 within MFs. Unexpectedly, using both fluorescence and confocal microscopy, we were unable to detect colocalization of GAP-43-positive axons with ZnT3-positive MF axons within the MF pathways, either in the region of the MF axons or in the SL, where MF terminals are abundant. In contrast, the plasma membrane-associated presynaptic marker SNAP-25 did colocalize with transgenic GAP-43-positive terminals in the SL. Synaptophysin, the vesicle-associated presynaptic terminal marker, colocalized with ZnT3 but did not appear to colocalize with GAP-43. The present findings raise important questions about the properties of granule cells and the MF mechanisms that differentially regulate axonal remodeling in the adult hippocampus: (1) Because there appears to be at least two populations of granule cells defined by their differential protein expression, this points to the existence of an intrinsic heterogeneity of granule cell expression beyond that contributed by adult neurogenesis; (2) Giventhe present evidence that growth is induced in mice overexpressing GAP-43 in adjacent non-GAP-43 containing MFs, the potential exists for a heretofore unexplored interaxonal communication mechanism.
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Affiliation(s)
- Jerome L Rekart
- Department of Psychology, Northwestern University, Evanston, IL 60208 USA.
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Prange-Kiel J, Fester L, Zhou L, Jarry H, Rune GM. Estrus cyclicity of spinogenesis: underlying mechanisms. J Neural Transm (Vienna) 2010; 116:1417-25. [PMID: 19730783 PMCID: PMC3085745 DOI: 10.1007/s00702-009-0294-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Accepted: 08/06/2009] [Indexed: 11/09/2022]
Abstract
Hippocampal spine density varies with the estrus cycle. The cyclic change in estradiol levels in serum was hypothesized to underlie this phenomenon, since treatment of ovariectomized animals with estradiol induced an increase in spine density in hippocampal dendrites of rats, as compared to ovariectomized controls. In contrast, application of estradiol to hippocampal slice cultures did not promote spinogenesis. In addressing this discrepancy, we found that hippocampal neurons themselves are capable of synthesizing estradiol de novo. Estradiol synthesis can be suppressed by aromatase inhibitors and by knock-down of Steroid Acute Regulatory Protein (StAR) and enhanced by substrates of steroidogenesis. Expression of estrogen receptors (ERs) and synaptic proteins, synaptogenesis, and long-term potentiation (LTP) correlated positively with aromatase activity in hippocampal cultures without any difference between genders. All effects due to inhibition of aromatase activity were rescued by application of estradiol to the cultures. Most importantly, gonadotropin-releasing hormone (GnRH) increased estradiol synthesis dose-dependently via an aromatase-mediated mechanism and consistently increased spine synapse density and spinophilin expression. As a consequence, our data suggest that cyclic fluctuations in spine synapse density result from pulsative release of GnRH from the hypothalamus and its effect on hippocampal estradiol synthesis, rather than from varying levels of serum estradiol. This hypothesis is further supported by higher GnRH receptor (GnRH-R) density in the hippocampus than in the cortex and hypothalamus and the specificity of estrus cyclicity of spinogenesis in the hippocampus, as compared to the cortex.
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Affiliation(s)
- Janine Prange-Kiel
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
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Otani T, Maejima H, Tobimatsu Y, Shimada N, Toriyama M, Deie M. Synaptogenesis in the Contralateral Primary Motor Area after Focal Brain Infarction in Rats. J Phys Ther Sci 2010. [DOI: 10.1589/jpts.22.69] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Takuya Otani
- Graduate School of Health Sciences, Hiroshima University
| | | | | | - Noboru Shimada
- Graduate School of Health Sciences, Hiroshima University
| | | | - Masataka Deie
- Graduate School of Health Sciences, Hiroshima University
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Parpura V, Zorec R. Gliotransmission: Exocytotic release from astrocytes. ACTA ACUST UNITED AC 2009; 63:83-92. [PMID: 19948188 DOI: 10.1016/j.brainresrev.2009.11.008] [Citation(s) in RCA: 283] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 11/22/2009] [Accepted: 11/24/2009] [Indexed: 01/28/2023]
Abstract
Gliotransmitters are chemicals released from glial cells fulfilling a following set of criteria: (i) they are synthesized by and/or stored in glia; (ii) their regulated release is triggered by physiological and/or pathological stimuli; (iii) they activate rapid (milliseconds to seconds) responses in neighboring cells; and (iv) they play a role in (patho)physiological processes. Astrocytes can release a variety of gliotransmitters into the extracellular space using several different mechanisms. In this review, we focus on exocytotic mechanism(s) underlying the release of three classes of gliotransmitters: (i) amino acids, such as, glutamate and d-serine; (ii) nucleotides, like adenosine 5'-triphosphate; and (iii) peptides, such as, atrial natriuretic peptide and brain-derived neurotrophic factor. It is becoming clear that astrocytes are endowed with elements that qualify them as cells communicating with neurons and other cells within the central nervous system by employing regulated exocytosis.
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Affiliation(s)
- Vladimir Parpura
- Department of Neurobiology, Center for Glial Biology in Medicine, Civitan International Research Center, Atomic Force Microscopy & Nanotechnology Laboratories, and Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, USA.
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31
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Crane JW, Baiquni GP, Sullivan RK, Lee JD, Sah P, Taylor SM, Noakes PG, Woodruff TM. The C5a anaphylatoxin receptor CD88 is expressed in presynaptic terminals of hippocampal mossy fibres. J Neuroinflammation 2009; 6:34. [PMID: 19917081 PMCID: PMC2780381 DOI: 10.1186/1742-2094-6-34] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 11/16/2009] [Indexed: 12/20/2022] Open
Abstract
Background In the periphery, C5a acts through the G-protein coupled receptor CD88 to enhance/maintain inflammatory responses. In the brain, CD88 can be expressed on astrocytes, microglia and neurons. Previous studies have shown that the hippocampal CA3 region displays CD88-immunolabelling, and CD88 mRNA is present within dentate gyrus granule cells. As granule cells send dense axonal projections (mossy fibres) to CA3 pyramidal neurons, CD88 expression could be expressed on mossy fibres. However, the cellular location of CD88 within the hippocampal CA3 region is unknown. Methods The expression of CD88 within the hippocampal CA3 region was characterized using dual-immunolabelling of hippocampal sections prepared from Wistar rats. Immunolabelling for CD88, using a monoclonal antibody, was combined with immunolabelling for markers of astrocytes (GFAP), microglia (IBA1), presynaptic proteins (synaptophysin and synapsin-1) and preterminal axons (neurofilament). In addition, electron microscopy was performed on peroxidase-visualized CD88-immunolabelling to determine its cellular localisation within the CA3 region. Results Dense CD88-immunolabelling was observed within the stratum lucidum of the CA3, consistent with the presence of CD88 on mossy fibres. Labelling for CD88 rarely co-localized with astrocytes or microglia, but was highly co-localized with presynaptic proteins. Electron microscopy revealed CD88-immunolabelling was localized to large presynaptic terminals within the stratum lucidum. Conclusion These results demonstrate that CD88 is expressed on presynaptic terminals of mossy fibres within the CA3 region of the hippocampus. Although the role of CD88 on mossy fibres remains to be established, their involvement in synaptic/cellular plasticity, and in cognitive disorders such as Alzheimer's disease deserves investigation.
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Affiliation(s)
- James W Crane
- Queensland Brain Institute, The University of Queensland, St, Lucia, Brisbane, Qld, 4072 Australia.
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A critical period for activity-dependent synaptic development during olfactory bulb adult neurogenesis. J Neurosci 2009; 29:11852-8. [PMID: 19776271 DOI: 10.1523/jneurosci.2406-09.2009] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
New neurons integrate in large numbers into the mature olfactory bulb circuit throughout life. The factors controlling the synaptic development of adult-born neurons and their connectivity remain essentially unknown. We examined the role of activity-dependent mechanisms in the synaptic development of adult-born neurons by genetic labeling of synapses while manipulating sensory input or cell-intrinsic excitability. Sensory deprivation induced marked changes in the density of input and output synapses during the period when new neurons develop most of their synapses. In contrast, when sensory deprivation started after synaptic formation was complete, input synapses increased in one domain without detectable changes in the other dendritic domains. We then investigated the effects of genetically raising the intrinsic excitability of new neurons on their synaptic development by delivering a voltage-gated sodium channel that triggers long depolarizations. Surprisingly, genetically increasing excitability did not affect synaptic development but rescued the changes in glutamatergic input synapses caused by sensory deprivation. These experiments show that, during adult neurogenesis in the olfactory bulb, synaptic plasticity is primarily restricted to an early period during the maturation of new neurons when they are still forming synapses. The addition of cells endowed with such an initial short-lived flexibility and long-term stability may enable the processing of information by the olfactory bulb to be both versatile and reliable in the face of changing behavioral demands.
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Rubino T, Realini N, Braida D, Guidi S, Capurro V, Viganò D, Guidali C, Pinter M, Sala M, Bartesaghi R, Parolaro D. Changes in hippocampal morphology and neuroplasticity induced by adolescent THC treatment are associated with cognitive impairment in adulthood. Hippocampus 2009; 19:763-72. [PMID: 19156848 DOI: 10.1002/hipo.20554] [Citation(s) in RCA: 210] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Marijuana and hashish are the illicit drugs most frequently used by human adolescents. Given the continued neurodevelopment throughout adolescence, adolescents may be more vulnerable than adults to certain neural consequences of heavy marijuana use. This study aimed to assess whether an experimental model of adolescent chronic exposure to Delta9-tetrahydrocannabinol (THC), may induce lasting effects on learning and memory. Adolescent rats have been treated with THC or its vehicle from 35 to 45 postnatal days (PND) and left undisturbed until their adulthood (75 PND) when aversive and spatial memory was assessed using the passive avoidance and radial maze tasks. No alteration was found in aversive memory, but in the radial maze THC pretreated animals exhibited a worse performance than vehicles, suggesting a deficit in spatial working memory. To correlate memory impairment to altered neuroplasticity, level of marker proteins was investigated in the hippocampus, the most relevant area mediating spatial memory. A significant decrease in the astroglial marker glial fibrillar acid protein was found as well as in pre- and postsynaptic protein expression (VAMP2, PSD95) and NMDA receptor levels in pretreated rats. To parallel these changes to alteration in dendritic morphology, Golgi-Cox staining was performed in the hippocampal dentate gyrus. Pretreated rats had a significantly lower total dendritic length and number than vehicles, as well as reduced spine density. Our data suggest that THC pretreated rats may establish less synaptic contacts and/or less efficient synaptic connections throughout the hippocampus and this could represent the molecular underpinning of the cognitive deficit induced by adolescent THC treatment.
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Affiliation(s)
- Tiziana Rubino
- DBSF and Neuroscience Center, University of Insubria, Busto Arsizio, VA, Italy.
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Poorly Differentiated Colorectal Adenocarcinoma (Methodology). COLORECTAL CANCER 2009. [DOI: 10.1007/978-1-4020-9545-0_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Xu AJ, Kuramasu A, Maeda K, Kinoshita K, Takayanagi S, Fukushima Y, Watanabe T, Yanagisawa T, Sukegawa J, Yanai K. Agonist-induced internalization of histamine H2 receptor and activation of extracellular signal-regulated kinases are dynamin-dependent. J Neurochem 2008; 107:208-17. [PMID: 18691388 DOI: 10.1111/j.1471-4159.2008.05608.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Histamine H2 receptor (H2R) is a member of G protein-coupled receptor family. Agonist stimulation of H2R results in several cellular events including activation of adenylate cyclase and phospholipase C, desensitization of the receptor, activation of extracellular signal-regulated kinases ERK1/2, and receptor endocytosis. In this study, we identified a GTPase dynamin as a binding partner of H2R. Dynamin could associate with H2R both in vitro and in vivo. Functional analyses using dominant-negative form of dynamin (K44E-dynamin) revealed that cAMP production and the following H2R desensitization are independent of dynamin. However, the agonist-induced H2R internalization was inhibited by co-expression of K44E-dynamin. Furthermore, activation of extracellular-signal regulated kinases ERK1/2 in response to dimaprit, an H2R agonist, was attenuated by K44E-dynamin. Although H2R with truncation of 51 amino acids at its carboxy-terminus did not internalize after agonist stimulation, it still activated ERK1/2, but the degree of this activation was less than that of the wild-type receptor. Finally, K44E dynamin did not affect ERK1/2 activation induced by internalization-deficient H2R. These results suggest that the agonist-induced H2R internalization and ERK1/2 activation are partially dynamin-dependent. Furthermore, ERK1/2 activation via H2R is likely dependent of the endocytotic process rather than dynamin itself.
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Affiliation(s)
- A-Jing Xu
- Departments of Pharmacology, Tohoku University School of Medicine, Seiryo-machi, Aoba-ku, Sendai, Japan
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Bryan K, Lee HG, Perry G, Castellani RJ, Smith MA, Casadesus G. Nonestrogen-based hormonal therapies for Alzheimer’s disease. FUTURE NEUROLOGY 2008. [DOI: 10.2217/14796708.3.4.399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Alzheimer’s disease (AD) is becoming increasingly more prevalent worldwide and is a costly, devastating disease. The fact that females are more likely to be diagnosed with AD than men has contributed to the large amount of research and literature on estrogen’s ability to rescue cognitive decline in aging females. However, recent results from the Women’s Health Initiative Memory Study (WHIMS) and the Research into Memory, Brain Function and Estrogen Replacement (REMEMBER) study, in which estrogen-replacement therapy is shown not to be beneficial to cognition in postmenopausal women, especially in women of more advanced ages, have opened the study of hormones and hormone-based therapies beyond that of sex steroids. As such, recent findings, and the focus of this review, indicate that gonadotropins such as luteinizing hormone have a role on cognitive function and AD. It is likely that the interplay of age, and the timing of estrogen and these other less studied hormones will allow us to gain a better understanding of hypothalamic–pituitary–gonadal axis regulation after menopause and how it relates to AD, and will hopefully lead to new avenues of treatment for AD.
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Affiliation(s)
- Kathryn Bryan
- Case Western Reserve University, Department of Neurosciences, 2109 Adelbert Road, Cleveland, OH 44106, USA
| | - Hyoung-gon Lee
- Case Western Reserve University, Department of Pathology, 2109 Adelbert Road, Cleveland, OH 44106, USA
| | - George Perry
- Case Western Reserve University, Department of Pathology, 2109 Adelbert Road, Cleveland, OH 44106, and, University of Texas at San Antonio, College of Sciences, 6900 North Loop, 1604 West San Antonio, TX 78249, USA
| | - Rudy J Castellani
- University of Maryland, Department of Pathology, 22 South Greene Street, NBW81, Baltimore, MD 21201, USA
| | - Mark A Smith
- Case Western Reserve University, Department of Pathology, 2109 Adelbert Road, Cleveland, OH 44106, USA
| | - Gemma Casadesus
- Case Western Reserve University, Department of Neurosciences, 2109 Adelbert Road, Cleveland, OH 44106, USA
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Gadd JC, Kuyper CL, Fujimoto BS, Allen RW, Chiu DT. Sizing subcellular organelles and nanoparticles confined within aqueous droplets. Anal Chem 2008; 80:3450-7. [PMID: 18363409 PMCID: PMC2692466 DOI: 10.1021/ac8000385] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This article describes two complementary techniques, single-particle tracking and correlation spectroscopy, for accurately sizing nanoparticles confined within picoliter volume aqueous droplets. Single-particle tracking works well with bright particles that can be continuously illuminated and imaged, and we demonstrated this approach for sizing single fluorescent beads. Fluorescence correlation spectroscopy detects small intensity bursts from particles or molecules diffusing through the confocal probe volume, which works well with dim and rapidly diffusing particles or molecules; we demonstrated FCS for sizing synaptic vesicles confined in aqueous droplets. In combination with recent advances in droplet manipulations and analysis, we anticipate this capability to size single nanoparticles and molecules in free solution will complement existing tools for probing cellular systems, subcellular organelles, and nanoparticles.
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Affiliation(s)
- Jennifer C Gadd
- Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700, USA
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Fei GH, Feng ZP. Chronic hypoxia-induced alteration of presynaptic protein profiles and neurobehavioral dysfunction are averted by supplemental oxygen in Lymnaea stagnalis. Neuroscience 2008; 153:318-28. [DOI: 10.1016/j.neuroscience.2008.01.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Revised: 01/16/2008] [Accepted: 01/28/2008] [Indexed: 11/28/2022]
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Santos MS, Li H, Voglmaier SM. Synaptic vesicle protein trafficking at the glutamate synapse. Neuroscience 2008; 158:189-203. [PMID: 18472224 DOI: 10.1016/j.neuroscience.2008.03.029] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 02/25/2008] [Accepted: 03/08/2008] [Indexed: 11/27/2022]
Abstract
Expression of the integral and associated proteins of synaptic vesicles is subject to regulation over time, by region, and in response to activity. The process by which changes in protein levels and isoforms result in different properties of neurotransmitter release involves protein trafficking to the synaptic vesicle. How newly synthesized proteins are incorporated into synaptic vesicles at the presynaptic bouton is poorly understood. During synaptogenesis, synaptic vesicle proteins sort through the secretory pathway and are transported down the axon in precursor vesicles that undergo maturation to form synaptic vesicles. Changes in protein content of synaptic vesicles could involve the formation of new vesicles that either mix with the previous complement of vesicles or replace them, presumably by their degradation or inactivation. Alternatively, new proteins could individually incorporate into existing synaptic vesicles, changing their functional properties. Glutamatergic vesicles likely express many of the same integral membrane proteins and share certain common mechanisms of biogenesis, recycling, and degradation with other synaptic vesicles. However, glutamatergic vesicles are defined by their ability to package glutamate for release, a property conferred by the expression of a vesicular glutamate transporter (VGLUT). VGLUTs are subject to regional, developmental, and activity-dependent changes in expression. In addition, VGLUT isoforms differ in their trafficking, which may target them to different pathways during biogenesis or after recycling, which may in turn sort them to different vesicle pools. Emerging data indicate that differences in the association of VGLUTs and other synaptic vesicle proteins with endocytic adaptors may influence their trafficking. These observations indicate that independent regulation of synaptic vesicle protein trafficking has the potential to influence synaptic vesicle protein composition, the maintenance of synaptic vesicle pools, and the release of glutamate in response to changing physiological requirements.
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Affiliation(s)
- M S Santos
- Department of Psychiatry, University of California School of Medicine, 401 Parnassus Avenue, LPPI-A101, San Francisco, CA 94143-0984, USA
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40
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Affiliation(s)
- Andrew G Engel
- Department of Neurology, Mayo Clinic, Rochester, MN, USA.
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41
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42
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Irla M, Saade M, Fernandez C, Chasson L, Victorero G, Dahmane N, Chazal G, Nguyen C. Neuronal distribution of Spatial in the developing cerebellum and hippocampus and its somatodendritic association with the kinesin motor KIF17. Exp Cell Res 2007; 313:4107-19. [DOI: 10.1016/j.yexcr.2007.09.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2007] [Revised: 09/03/2007] [Accepted: 09/05/2007] [Indexed: 11/28/2022]
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43
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Abstract
Plasma membrane proteins serve essential functions for cells, interacting with both cellular and extracellular components, structures and signaling molecules. Additionally, plasma membrane proteins comprise more than two-thirds of the known protein targets for existing drugs. Consequently, defining membrane proteomes is crucial to understanding the role of plasma membranes in fundamental biological processes and for finding new targets for action in drug development. MS-based identification methods combined with chromatographic and traditional cell-biology techniques are powerful tools for proteomic mapping of proteins from organelles. However, the separation and identification of plasma membrane proteins remains a challenge for proteomic technology because of their hydrophobicity and microheterogeneity. Creative approaches to solve these problems and potential pitfalls will be discussed. Finally, a representative overview of the impressive achievements in this field will also be given.
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Affiliation(s)
- Djuro Josic
- Department of Medicine, Brown Medical School, Providence, RI, USA.
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44
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Rekart JL, Sandoval CJ, Bermudez-Rattoni F, Routtenberg A. Remodeling of hippocampal mossy fibers is selectively induced seven days after the acquisition of a spatial but not a cued reference memory task. Learn Mem 2007; 14:416-21. [PMID: 17554086 DOI: 10.1101/lm.516507] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Relating storage of specific information to a particular neuromorphological change is difficult because behavioral performance factors are not readily disambiguated from underlying cognitive processes. This issue is addressed here by demonstrating robust reorganization of the hippocampal mossy fiber terminal field (MFTF) when adult rats learn the location of a hidden platform but not when rats learn to locate a visible platform. Because the latter task requires essentially the same behavioral performance as the former, the observed MFTF growth is seen as the consequence of specific input-dependent hippocampal activity patterns selectively generated by processing of extramaze but not intramaze cues. Successful performance on the hidden platform task requires formation of spatial memory. Increased MFTFs in hidden platform-trained rats are observed 7 d but not 2 d after training nor in swim controls. These results suggest that structural plasticity of the mossy fiber:CA3 circuit may contribute to the maintenance of long-lasting memory but not to the initial storage of the spatial context.
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Affiliation(s)
- Jerome L Rekart
- Department of Psychology, Northwestern University, Evanston, Illinois 60208, USA.
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45
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Abstract
The procedure for the fabrication of a detector termed NACAD, nanofabricated carbon-based detector, is described. I characterized the mechanical properties of this detector using atomic force and scanning electron microscopy techniques. This detector exhibits a smooth surface (rms 2-4 nm) and easy access for atomic force microscopy tips, necessary features for biological studies of secretory granules and vesicles, which store transmitters and release them via exocytosis. The NACAD does not impair the elastic properties of granular matrixes deposited onto a detector, as they show their typical Young's moduli and ion exchanger properties; divalent histamine shrinks them, while monovalent sodium causes their swelling. Additionally, the NACADs' electrochemical properties allowed amperometric measurements of serotonin released from intact secretory granules isolated from mast cells, after removal of their granular membranes using a mild detergent treatment. Thus, this detector will aid future studies of single secretory granules and vesicles and their insoluble matrixes.
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Affiliation(s)
- Vladimir Parpura
- Department of Cell Biology and Neuroscience and Center for Nanoscale Science and Engineering, University of California, Riverside, California 92521, USA.
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46
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Fei G, Guo C, Sun HS, Feng ZP. Chronic hypoxia stress-induced differential modulation of heat-shock protein 70 and presynaptic proteins. J Neurochem 2007; 100:50-61. [PMID: 17227434 DOI: 10.1111/j.1471-4159.2006.04194.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Chronic hypoxia exposure can cause neurobehavioral dysfunction, but the underlying cellular and molecular mechanisms remain unclear. Here, we found that adult Lymnaea stagnalis snails maintained in low O(2) (approximately 5%) for 4 days developed slowed reactions to light stimuli, and reduced righting movement. Semiquantitative immunoblotting analyses showed that hypoxia exposure induced increased expression of heat-shock protein (HSP)70 in ganglion preparations, and suppressed expression of the presynaptic proteins syntaxin I, synaptic vesicle protein 2 (SV2) and synaptotagmin I. Detailed time course analyses showed that an early moderate increase developed within 6 h, preceding a substantial up-regulation of HSP70 after 4 days; an early reduction of syntaxin I in the first 24 h; a delayed reduction of synaptotagmin I after 4 days; and a biphasic change in SV2. Using a double-stranded RNA interference approach, we demonstrated that preventing the hypoxia inducible HSP70 enhanced down-regulation of syntaxin and synaptotagmin, and aggravated motor and sensory suppression. Co-immunoprecipitation analysis revealed an interaction between HSP70 and syntaxin. We have thus provided the first evidence that early induction of HSP70 by chronic hypoxia is critical for maintaining expression levels of presynaptic proteins. These findings implicate a new molecular mechanism underlying chronic hypoxia-induced neurobehavioral adaptation and impairment.
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Affiliation(s)
- Guanghe Fei
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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47
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Abstract
Synaptic vesicles mediate the release of neurotransmitters at nerve terminals. In this issue of Cell, Takamori et al. (2006) analyze the lipid and protein components of synaptic vesicles, providing the most comprehensive description of synaptic vesicles to date.
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Affiliation(s)
- Thomas C Südhof
- Center for Basic Neuroscience, Department of Molecular Genetics, Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX 75390, USA.
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48
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Li Y, Wu Y, Zhou Y. Modulation of inactivation properties of CaV2.2 channels by 14-3-3 proteins. Neuron 2006; 51:755-71. [PMID: 16982421 DOI: 10.1016/j.neuron.2006.08.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2005] [Revised: 05/08/2006] [Accepted: 08/08/2006] [Indexed: 11/28/2022]
Abstract
Inactivation of presynaptic Ca(V)2.2 channels may play a role in regulating short-term synaptic plasticity. Here, we report a direct modulation of Ca(V)2.2 channel inactivation properties by 14-3-3, a family of signaling proteins involved in a wide range of biological processes. The structural elements critical for 14-3-3 binding and channel modulation lie in the carboxyl tail of the pore-forming alpha(1B) subunit, where we have identified two putative 14-3-3 interaction sites, including a phosphoserine-containing motif that directly binds to 14-3-3 and a second region near the EF hand and IQ domain. In transfected tsA 201 cells, 14-3-3 coexpression dramatically slows open-state inactivation and reduces cumulative inactivation of Ca(V)2.2 channels. In hippocampal neurons, interference with 14-3-3 binding accelerates Ca(V)2.2 channel inactivation and enhances short-term synaptic depression. These results demonstrate that 14-3-3 proteins are important regulators of Ca(V)2.2 channel activities and through this mechanism may contribute to their regulation of synaptic transmission and plasticity.
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MESH Headings
- 14-3-3 Proteins/genetics
- 14-3-3 Proteins/metabolism
- 14-3-3 Proteins/physiology
- Amino Acid Sequence
- Animals
- Binding Sites/genetics
- Binding, Competitive
- Blotting, Western
- Brain/cytology
- Brain/metabolism
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Calcium Channels, N-Type/genetics
- Calcium Channels, N-Type/metabolism
- Calcium Channels, T-Type/genetics
- Calcium Channels, T-Type/metabolism
- Cell Line
- Cells, Cultured
- Glutathione Transferase/genetics
- Glutathione Transferase/metabolism
- Humans
- Neurons/cytology
- Neurons/metabolism
- Phosphorylation
- Protein Binding
- Protein Subunits/genetics
- Protein Subunits/metabolism
- Rats
- Rats, Sprague-Dawley
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Synaptic Transmission/physiology
- Time Factors
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Affiliation(s)
- Yong Li
- Department of Neurobiology, Evelyn F. McKnight Brain Institute and Civitan International Research Center, School of Medicine, University of Alabama at Birmingham, 35294, USA
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Yoshioka M, Tashiro Y, Inoue K, Kawai Y. Postnatal development of GABAergic axon terminals in the rat nucleus of tractus solitarius. Brain Res 2006; 1107:111-20. [PMID: 16828714 DOI: 10.1016/j.brainres.2006.06.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Revised: 05/31/2006] [Accepted: 06/01/2006] [Indexed: 01/18/2023]
Abstract
The proper function of the brain depends on a precise arrangement of excitatory and inhibitory synapses. Although the caudal nucleus of tractus solitarius (cNTS) plays a pivotal role in cardiorespiratory reflexes, we know little about the formation of the local neural network in the cNTS. In the present study, we have focused on GABAergic axon terminals and investigated postnatal changes in GABAergic synaptic organizations in the rat cNTS immunocytochemically at both light and electron microscopic levels. Counting synaptic and non-synaptic GABAergic axon terminals revealed that GABAergic axon terminal number in the cNTS seemed constant until the second postnatal week and that GABAergic axon terminals were reorganized around postnatal day 10 (P10). Electron microscopic observation revealed that more than 20% GABAergic axon terminals formed axosomatic synapses at P2 to P4, but the number of GABAergic axosomatic synapse on neurons with smaller soma (smaller neurons) decreased considerably after P8. Orphan GABAergic boutons were present around somata of smaller neurons at P10, and axodendritic synapse number on thicker dendrites decreased gradually during postnatal development. These results show that GABAergic axon terminals detach from somata of smaller neurons at the second postnatal week. Such morphologic changes in axon terminals could cause changes in electrophysiological activity and might contribute to reorganization of the local network within the cNTS from neonatal to adult type. These postnatal changes in the cNTS local network might be prerequisite for the cardiorespiratory reflexes of the adult type.
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Affiliation(s)
- Masayuki Yoshioka
- Department of Anatomy I, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi Minato-ku, Tokyo 105-8461, Japan
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50
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Abstract
Cecal extrapulmonary small cell carcinoma (cESC) is extremely rare, with only single previous report of occurrence in a child. We report a 76-year-old man admitted for evaluation of a cecal mass seen in colonoscopy. Histology revealed small cell carcinoma with classic immunohistochemical profile similar to those seen in the colon. Further clinical survey documented absence of any other masses or abnormality. To the best of our knowledge, this is the first case of primary cESC occurring in an adult. Awareness of the pathologist and clinician of the cecum as a potential site of cESC may help to prevent misdiagnosis as poorly differentiated adenocarcinoma. This is crucial because extrapulmonary small cell carcinomas usually have worse prognosis.
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Affiliation(s)
- Dina El Demellawy
- Department of Anatomical Pathology and Laboratory Medicine, McMaster University, Hamilton, Ontario, Canada
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