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Long LH, Liu RL, Wang F, Liu J, Hu ZL, Xie N, Jin Y, Fu H, Chen JG. AGE-RELATED SYNAPTIC CHANGES IN THE CA1 STRATUM RADIATUM AND SPATIAL LEARNING IMPAIRMENT IN RATS. Clin Exp Pharmacol Physiol 2009; 36:675-81. [DOI: 10.1111/j.1440-1681.2008.05132.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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52
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Abstract
The age of an experimental animal can be a critical variable, yet age matters are often overlooked within neuroscience. Many studies make use of young animals, without considering possible differences between immature and mature subjects. This is especially problematic when attempting to model traits or diseases that do not emerge until adulthood. In this commentary we discuss the reasons for this apparent bias in age of experimental animals, and illustrate the problem with a systematic review of published articles on long-term potentiation. Additionally, we review the developmental stages of a rat and discuss the difficulty of using the weight of an animal as a predictor of its age. Finally, we provide original data from our laboratory and review published data to emphasize that development is an ongoing process that does not end with puberty. Developmental changes can be quantitative in nature, involving gradual changes, rapid switches, or inverted U-shaped curves. Changes can also be qualitative. Thus, phenomena that appear to be unitary may be governed by different mechanisms at different ages. We conclude that selection of the age of the animals may be critically important in the design and interpretation of neurobiological studies.
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Affiliation(s)
- James Edgar McCutcheon
- Department of Cellular and Molecular Pharmacology, Rosalind Franklin University of Medicine and Science, The Chicago Medical School, 3333 Green Bay Road, North Chicago, IL 60064, USA
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53
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Popov VI, Stewart MG. Complexity of contacts between synaptic boutons and dendritic spines in adult rat hippocampus: Three-dimensional reconstructions from serial ultrathin sections in vivo. Synapse 2009; 63:369-77. [DOI: 10.1002/syn.20613] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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54
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Chaudhury S, Nag TC, Wadhwa S. Effect of prenatal auditory stimulation on numerical synaptic density and mean synaptic height in the posthatch Day 1 chick hippocampus. Synapse 2009; 63:152-9. [PMID: 19021205 DOI: 10.1002/syn.20585] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Previous studies on prenatal auditory stimulation by species-specific sound or sitar music showed enhanced morphological and biochemical changes in chick hippocampus, which plays an important role in learning and memory. Changes in the efficiency of synapses, synaptic morphology and de novo synapse formation affects learning and memory. Therefore, in the present study, we set out to investigate the mean synaptic density and mean synaptic height at posthatch Day 1 in dorsal and ventral part of chick hippocampus following prenatal auditory stimulation. Fertilized 0 day eggs of domestic chick incubated under normal conditions were exposed to patterned sounds of species-specific and sitar music at 65 dB levels for 15 min/h round the clock (frequency range: 100-6300 Hz) from embryonic Day 10 till hatching. The synapses identified under transmission electron microscope were estimated for their numerical density by physical disector method and also the mean synaptic height calculated. Our results demonstrate a significant increase in mean synaptic density with no alterations in the mean synaptic height following both types of auditory stimulation in the dorsal as well as ventral part of the hippocampus. The observed increase in mean synaptic density suggests enhanced synaptic substrate to strengthen hippocampal function.
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Affiliation(s)
- Sraboni Chaudhury
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi 110029, India
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55
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OKA T, TOMINAGA Y, WAKABAYASHI Y, SHOJI A, SUGAWARA M. Comparison of the L-Glutamate Level in Mouse Hippocampal Slices under Tetraethylammonium Chloride Stimulation as Measured with a Glass Capillary Sensor and a Patch Sensor. ANAL SCI 2009; 25:353-8. [DOI: 10.2116/analsci.25.353] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Takayuki OKA
- Department of Chemistry, College of Humanities and Sciences, Nihon University
| | - Yumiko TOMINAGA
- Department of Chemistry, College of Humanities and Sciences, Nihon University
| | | | - Atsushi SHOJI
- Department of Chemistry, College of Humanities and Sciences, Nihon University
| | - Masao SUGAWARA
- Department of Chemistry, College of Humanities and Sciences, Nihon University
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56
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Bourne JN, Harris KM. Balancing structure and function at hippocampal dendritic spines. Annu Rev Neurosci 2008; 31:47-67. [PMID: 18284372 DOI: 10.1146/annurev.neuro.31.060407.125646] [Citation(s) in RCA: 669] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Dendritic spines are the primary recipients of excitatory input in the central nervous system. They provide biochemical compartments that locally control the signaling mechanisms at individual synapses. Hippocampal spines show structural plasticity as the basis for the physiological changes in synaptic efficacy that underlie learning and memory. Spine structure is regulated by molecular mechanisms that are fine-tuned and adjusted according to developmental age, level and direction of synaptic activity, specific brain region, and exact behavioral or experimental conditions. Reciprocal changes between the structure and function of spines impact both local and global integration of signals within dendrites. Advances in imaging and computing technologies may provide the resources needed to reconstruct entire neural circuits. Key to this endeavor is having sufficient resolution to determine the extrinsic factors (such as perisynaptic astroglia) and the intrinsic factors (such as core subcellular organelles) that are required to build and maintain synapses.
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Affiliation(s)
- Jennifer N Bourne
- Center for Learning and Memory, Department of Neurobiology, University of Texas, Austin, Texas 78712-0805, USA.
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57
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Abstract
Stable expression of long-term synaptic plasticity is critical for the developmental refinement of neural circuits and for some forms of learning and memory. Although structural remodeling of dendritic spines is associated with the stable expression of long-term potentiation (LTP), the relationship between structural and physiological plasticity remains unclear. To define whether these two processes are related or distinct, we simultaneously monitored EPSPs and dendritic spines, using combined patch-clamp recording and two-photon time-lapse imaging in the same CA1 pyramidal neurons in acute hippocampal slices. We found that theta burst stimulation paired with postsynaptic spiking, which reliably induced LTP, also induced a rapid and persistent expansion of dendritic spines. Like LTP, this expansion was NMDA receptor dependent. Spine expansion occurred even when LTP was inhibited by postsynaptic inhibition of exocytosis or PKA (protein kinase A); however, under these conditions, the spine expansion was unstable and collapsed spontaneously. Furthermore, similar changes in LTP and spine expansion were observed when hippocampal neurons were treated with protein synthesis inhibitors. Like LTP, spine expansion was reversed by low-frequency stimulation (LFS) via a phosphatase-dependent mechanism, but only if the LFS was applied in a critical time window after induction. These results indicate that the initial expression of LTP and spine expansion is dissociable, but there is a high degree of mechanistic overlap between the stabilization of structural plasticity and LTP.
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58
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Stewart M, Popov V, Medvedev N, Gabbott P, Corbett N, Kraev I, Davies H. WITHDRAWN: Dendritic Spine and Synapse Morphological Alterations Induced by a Neural Cell Adhesion Molecule (NCAM) Mimetic. Neurochem Res 2008. [PMID: 18338259 DOI: 10.1007/s11064-008-9607-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Accepted: 01/24/2008] [Indexed: 09/29/2022]
Abstract
The neural cell adhesion molecule (NCAM) is a glycoprotein expressed on the surface of neurons and glial cells. It plays a key role in morphogenesis of the nervous system, regeneration of damaged neural tissue and synaptic plasticity. The extracellular domain of NCAM engages in homophilic interactions (NCAM binding to NCAM) and in heterophilic interactions between NCAM and other proteins such as the fibroblast growth factor (FGF) receptor. It promotes synaptogenesis and activity-dependent remodelling of synapses but less is know of its influence on synaptic and dendritic morphology. Recently, quantitative electron microscopy and 3-dimensional reconstruction (3-D) of ultrathin serial sections has been used to examine the morphology of synapses and dendritic spines in the hippocampus of rats treated with a neural cell adhesion molecule-derived fibroblast growth factor receptor agonist, FGL-peptide (an NCAM mimetic). These data show clearly that the FGL peptide has marked influences on both spine and synaptic form.
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Affiliation(s)
- Michael Stewart
- Faculty of Sciences, Department of Life Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK,
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59
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Impaired spatial memory and altered dendritic spine morphology in angiotensin II type 2 receptor-deficient mice. J Mol Med (Berl) 2008; 86:563-71. [PMID: 18335189 DOI: 10.1007/s00109-008-0316-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 01/29/2008] [Accepted: 01/30/2008] [Indexed: 10/22/2022]
Abstract
Mental retardation is the most frequent cause of serious handicap in children and young adults. Mutations in the human angiotensin II type 2 receptor (AT2) have been implicated in X-linked forms of mental retardation. We here demonstrate that mice lacking the AT2 receptor gene are significantly impaired in their performance in a spatial memory task and in a one-way active avoidance task. As no difference was observed between the genotypes in fear conditioning, the detected deficit in spatial memory may not relate to fear. Notably, receptor knockout mice showed increased motility in an activity meter and elevated plus maze. Importantly, these mice are characterized by abnormal dendritic spine morphology and length, both features also found to be associated with some cases of mental retardation. These findings suggest a crucial role of AT2 in normal brain function and that dysfunction of the receptor has impact on brain development and ultrastructural morphology with distinct consequences on learning and memory.
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60
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Abstract
Long-term potentiation (LTP), a cellular model of learning and memory, produces both an enhancement of synaptic function and an increase in the size of the associated dendritic spine. Synaptic insertion of AMPA receptors is known to play an important role in mediating the increase in synaptic strength during LTP, whereas the role of AMPA receptor trafficking in structural changes remains unexplored. Here, we examine how the cell maintains the correlation between spine size and synapse strength during LTP. We found that cells exploit an elegant solution by linking both processes to a single molecule: the AMPA-type glutamate receptor subunit 1 (GluR1). Synaptic insertion of GluR1 is required to permit a stable increase in spine size, both in hippocampal slice cultures and in vivo. Synaptic insertion of GluR1 is not sufficient to drive structural plasticity. Although crucial to the expression of LTP, the ion channel function of GluR1 is not required for the LTP-driven spine size enhancement. Remarkably, a recombinant cytosolic C-terminal fragment (C-tail) of GluR1 is driven to the postsynaptic density after an LTP stimulus, and the synaptic incorporation of this isolated GluR1 C-tail is sufficient to permit spine enlargement even when postsynaptic exocytosis of endogenous GluR1 is blocked. We conclude that during plasticity, synaptic insertion of GluR1 has two functions: the established role of increasing synaptic strength via its ligand-gated ion channel, and a novel role through the structurally stabilizing effect of its C terminus that permits an increase in spine size.
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61
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Medvedev NI, Rodríguez-Arellano JJ, Popov VI, Davies HA, Tigaret CM, Schoepfer R, Stewart MG. The glutamate receptor 2 subunit controls post-synaptic density complexity and spine shape in the dentate gyrus. Eur J Neurosci 2008; 27:315-25. [DOI: 10.1111/j.1460-9568.2007.06005.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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62
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De Roo M, Klauser P, Garcia PM, Poglia L, Muller D. Spine dynamics and synapse remodeling during LTP and memory processes. PROGRESS IN BRAIN RESEARCH 2008; 169:199-207. [PMID: 18394475 DOI: 10.1016/s0079-6123(07)00011-8] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
While changes in the efficacy of synaptic transmission are believed to represent the physiological bases of learning mechanisms, other recent studies have started to highlight the possibility that a structural reorganization of synaptic networks could also be involved. Morphological changes of the shape or size of dendritic spines or of the organization of postsynaptic densities have been described in several studies, as well as the growth and formation following stimulation of new protrusions. Confocal in vivo imaging experiments have further revealed that dendritic spines undergo a continuous turnover and replacement process that may vary as a function of development, but can be markedly enhanced by sensory activation or following brain damage. The implications of these new aspects of plasticity for learning and memory mechanisms are discussed.
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Affiliation(s)
- M De Roo
- Department of Neuroscience, Centre Médical Universitaire, 1211 Geneva 4, Switzerland
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63
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Oka T, Tasaki C, Sezaki H, Sugawara M. Implantation of a glass capillary-based enzyme electrode in mouse hippocampal slices for monitoring of L-glutamate release. Anal Bioanal Chem 2007; 388:1673-9. [PMID: 17632704 DOI: 10.1007/s00216-007-1428-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 06/08/2007] [Accepted: 06/08/2007] [Indexed: 11/24/2022]
Abstract
A glass capillary-based enzyme electrode (tip size approximately 10 microm) was implanted in the target neuronal region, i.e., dentate gyrus (DG) or cornu ammonis 1 (CA1), of acute brain slices at a depth of approximately 10 microm from the slice surface in order to allow the monitoring of chemical stimulant-induced changes in L-glutamate levels. First, the sampling behavior of a glass capillary in a slice was investigated by visualizing the transport of a fluorescence dye. Then, the electrode was applied to real-time monitoring of L-glutamate release in acute hippocampal slices stimulated by surface application of a stimulant solution. The extracellular application of KCl (0.10 M) increased the glutamate levels in the DG and CA1 regions, respectively. The enhancement of L-glutamate concentration at DG was much larger than at CA1. The application of tetraethylammonium chloride (TEA) (25 mM) enhanced the L-glutamate level in the DG region and the enhanced level did not return to the initial value before TEA application even when washed with an artificial cerebrospinal fluid (ACSF). The usefulness of a surface-implanted capillary electrode for monitoring L-glutamate release in acute brain slices is discussed.
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Affiliation(s)
- Takayuki Oka
- Department of Chemistry, College of Humanities and Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo, 156-8550, Japan
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64
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Bourne J, Harris KM. Do thin spines learn to be mushroom spines that remember? Curr Opin Neurobiol 2007; 17:381-6. [PMID: 17498943 DOI: 10.1016/j.conb.2007.04.009] [Citation(s) in RCA: 667] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2007] [Accepted: 04/27/2007] [Indexed: 11/19/2022]
Abstract
Dendritic spines are the primary site of excitatory input on most principal neurons. Long-lasting changes in synaptic activity are accompanied by alterations in spine shape, size and number. The responsiveness of thin spines to increases and decreases in synaptic activity has led to the suggestion that they are 'learning spines', whereas the stability of mushroom spines suggests that they are 'memory spines'. Synaptic enhancement leads to an enlargement of thin spines into mushroom spines and the mobilization of subcellular resources to potentiated synapses. Thin spines also concentrate biochemical signals such as Ca(2+), providing the synaptic specificity required for learning. Determining the mechanisms that regulate spine morphology is essential for understanding the cellular changes that underlie learning and memory.
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Affiliation(s)
- Jennifer Bourne
- Center for Learning and Memory, Department of Neurobiology, University of Texas, Austin, TX 78712-0805, USA
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65
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Abstract
In excitatory neurons, most glutamatergic synapses are made on the heads of dendritic spines, each of which houses the postsynaptic terminal of a single glutamatergic synapse. We review recent studies demonstrating in vivo that spines are motile and plastic structures whose morphology and lifespan are influenced, even in adult animals, by changes in sensory input. However, most spines that appear in adult animals are transient, and the addition of stable spines and synapses is rare. In vitro studies have shown that patterns of neuronal activity known to induce synaptic plasticity can also trigger changes in spine morphology. Therefore, it is tempting to speculate that the plastic changes of spine morphology reflect the dynamic state of its associated synapse and are responsible to some extent for neuronal circuitry remodeling. Nevertheless, morphological changes are not required for all forms of synaptic plasticity, and whether changes in the spine shape and size significantly impact synaptic signals is unclear.
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Affiliation(s)
- Veronica A Alvarez
- Harvard Medical School, Department of Neurobiology, Boston, Massachusetts 02115, USA.
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66
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Lively S, Ringuette MJ, Brown IR. Localization of the extracellular matrix protein SC1 to synapses in the adult rat brain. Neurochem Res 2006; 32:65-71. [PMID: 17151913 DOI: 10.1007/s11064-006-9226-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Accepted: 11/06/2006] [Indexed: 10/23/2022]
Abstract
Extracellular matrix molecules play important roles in neural developmental processes such as axon guidance and synaptogenesis. When development is complete, many of these molecules are down-regulated, however the molecules that remain highly expressed are often involved in modulation of synaptic function. SC1 is an example of an extracellular matrix protein whose expression remains high in the adult rat brain. Confocal microscopy revealed that SC1 demonstrates a punctate pattern in synaptic enriched regions of the cerebral cortex and cerebellum. Higher resolution analysis using electron microscopy indicated that SC1 localizes to synapses, particularly the postsynaptic terminal. SC1 was also detected in perisynaptic glial processes that envelop synapses.
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Affiliation(s)
- Starlee Lively
- Center for the Neurobiology of Stress, University of Toronto at Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4
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67
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Donohue HS, Gabbott PLA, Davies HA, Rodríguez JJ, Cordero MI, Sandi C, Medvedev NI, Popov VI, Colyer FM, Peddie CJ, Stewart MG. Chronic restraint stress induces changes in synapse morphology in stratum lacunosum-moleculare CA1 rat hippocampus: a stereological and three-dimensional ultrastructural study. Neuroscience 2006; 140:597-606. [PMID: 16600515 DOI: 10.1016/j.neuroscience.2006.02.072] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Revised: 02/21/2006] [Accepted: 02/28/2006] [Indexed: 11/22/2022]
Abstract
Chronic restraint stress is known to affect the morphology and synaptic organization of the hippocampus, predominantly within CA3 but also in CA1 and dentate gyrus. In this study, we provide the first evidence for specific ultrastructural alterations affecting asymmetric axo-spinous synapses in CA1 stratum lacunosum-moleculare following chronic restraint stress (6 h/day, 21 days) in the rat. The structure of asymmetric axo-spinous post-synaptic densities was investigated using serial section three-dimensional reconstruction procedures in control (n=4) and chronic restraint stress (n=3) animals. Dendritic spine profiles (spine head+neck) associated with the sampled synaptic contacts (30 per animal) were also reconstructed in three-dimensions. Morphometric analyses revealed a significant increase in post-synaptic density surface area (+36%; P=0.03) and a highly significant increase in post-synaptic density volume (+79%; P=0.003) in the chronic restraint stress group. These changes were directly associated with 'non-macular' (perforated, complex and segmented) post-synaptic densities. A highly significant overall increase in the 'post-synaptic density surface area/spine surface area' ratio was also detected in the chronic restraint stress group (+27%; P=0.002). In contrast, no quantitative changes in spine parameters were found between groups. The Cavalieri method was used to assess the effects of chronic restraint stress exposure upon CA1 hippocampal volume. The mean volume of total dorsal anterior CA1 hippocampus was significantly lower in the chronic restraint stress group (-16%; P=0.036). However, when corrected for volume changes, no significant alteration in a relative estimate of the mean number of asymmetric axo-spinous synapses was detected in CA1 stratum lacunosum-moleculare between control and chronic restraint stress groups. The data indicate a structural remodeling of excitatory axo-spinous synaptic connectivity in rat CA1 stratum lacunosum-moleculare as a result of chronic restraint stress.
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MESH Headings
- Animals
- Atrophy/etiology
- Atrophy/pathology
- Atrophy/physiopathology
- Brain Damage, Chronic/etiology
- Brain Damage, Chronic/pathology
- Brain Damage, Chronic/physiopathology
- Chronic Disease
- Dendritic Spines/pathology
- Disease Models, Animal
- Hippocampus/pathology
- Hippocampus/physiopathology
- Image Cytometry
- Male
- Memory Disorders/etiology
- Memory Disorders/pathology
- Memory Disorders/physiopathology
- Microscopy, Electron, Transmission
- Neuronal Plasticity/physiology
- Presynaptic Terminals/pathology
- Pyramidal Cells/pathology
- Rats
- Rats, Wistar
- Receptors, AMPA/physiology
- Restraint, Physical/adverse effects
- Stress, Psychological/complications
- Synapses/pathology
- Synaptic Membranes/pathology
- Synaptic Transmission/physiology
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Affiliation(s)
- H S Donohue
- Department of Biological Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
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68
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Ninan I, Liu S, Rabinowitz D, Arancio O. Early presynaptic changes during plasticity in cultured hippocampal neurons. EMBO J 2006; 25:4361-71. [PMID: 16957772 PMCID: PMC1570425 DOI: 10.1038/sj.emboj.7601318] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Accepted: 08/08/2006] [Indexed: 11/09/2022] Open
Abstract
Long-lasting increase in synaptic strength is thought to underlie learning. An explosion of data has characterized changes in postsynaptic (pstS) AMPA receptor cycling during potentiation. However, changes occurring within the presynaptic (prS) terminal remain largely unknown. We show that appearance of new release sites during potentiation between cultured hippocampal neurons is due to (a) conversion of nonrecycling sites to recycling sites, (b) formation of new releasing sites from areas containing diffuse staining for the prS marker Vesicle-Associated Membrane Protein-2 and (c) budding of new recycling sites from previously existing recycling sites. In addition, potentiation is accompanied by a release probability increase in pre-existing boutons depending upon their individual probability. These prS changes precede and regulate fluorescence increase for pstS GFP-tagged-AMPA-receptor subunit GluR1. These results suggest that potentiation involves early changes in the prS terminal including remodeling and release probability increase of pre-existing synapses.
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Affiliation(s)
- Ipe Ninan
- Taub Institute and Department of Pathology, Columbia University, New York City, NY, USA
| | - Shumin Liu
- Taub Institute and Department of Pathology, Columbia University, New York City, NY, USA
| | - Daniel Rabinowitz
- Department of Statistics, Columbia University, New York City, NY, USA
| | - Ottavio Arancio
- Taub Institute and Department of Pathology, Columbia University, New York City, NY, USA
- Taub Institute and Department of Pathology, Columbia University, P&S 12-442, 630W, 168th Street, New York City, NY 10032, USA. Tel.: +1 212 342 5527; Fax: +1 212 342 5523; E-mail:
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69
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Critchlow HM, Maycox PR, Skepper JN, Krylova O. Clozapine and haloperidol differentially regulate dendritic spine formation and synaptogenesis in rat hippocampal neurons. Mol Cell Neurosci 2006; 32:356-65. [PMID: 16844384 DOI: 10.1016/j.mcn.2006.05.007] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2006] [Revised: 05/22/2006] [Accepted: 05/25/2006] [Indexed: 10/24/2022] Open
Abstract
Antipsychotic drugs are the primary therapeutic treatment for schizophrenia. In addition to their dopaminergic/serotonergic function, atypical antipsychotics differ from conventional antipsychotics in the way they affect glutamatergic receptor function. A cellular correlate of this may be the modulation of dendritic spines (DS). Here, we demonstrate that in rat dissociated hippocampal neurons 1.0 microM clozapine administration increased DS-enriched protein spinophilin by 70%, increased post-synaptic protein shank1a puncta density by 26% and increased overall primary dendrite DS density by 59%. Filopodia and mushroom DS were particularly affected by clozapine. Conversely, 0.1 microM haloperidol decreased spinophilin protein by 40%, caused a 25% decrease in shank1a puncta and reduced the numbers of filopodia. In contrast, neither haloperidol nor clozapine induced any change in the levels of the pre-synaptic protein synapsin. This indicates that clozapine and haloperidol differentially regulate DS and post-synaptic plasticity. These findings may provide a molecular and cellular correlate to the superior therapeutic profile of clozapine when compared with haloperidol.
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Affiliation(s)
- H M Critchlow
- Department of Physiology, Development and Neuroscience, University of Cambridge, UK.
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