Chapter 11 Spine dynamics and synapse remodeling during LTP and memory processes

Department of Neuroscience, Centre Médical Universitaire, 1211 Geneva 4, Switzerland.
Progress in brain research (Impact Factor: 2.83). 02/2008; 169:199-207. DOI: 10.1016/S0079-6123(07)00011-8
Source: PubMed


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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    • "During brain ontogenesis, overproduction of synapses and their subsequent elimination through activity-dependent processes are critical for correct refinement and normal functioning of neural circuits.36,37 Moreover, dynamic processes of assembly and disassembly of synapses persist into adulthood;38,39 in rodent hippocampus, including CA1, synapse density has been shown to increase into adult age,40,41 nearly doubling between postnatal day 15 and 48,42 thus pointing to a highly protracted period of synapse formation and refinement. The increase of axo-spinous synapses observed in CA1 stratum radiatum of adult rats maternally exposed to excess of α-T may reflect an aberrant gauging of synapse production/elimination balance during hippocampal maturation. "
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    • "NMDAR-mediated influx of Ca+2 contributes to the long term potentiation, thereby controlling the behavioral learning, fear response and extinction [66], [69], [74]. Related observation of elevated mGluR2 (GRM2) in FD-fed mice was rather counterintuitive. "
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    PLoS ONE 03/2014; 9(3):e90425. DOI:10.1371/journal.pone.0090425 · 3.23 Impact Factor
    • "elation between the intensity of cocaine seeking and both morphological and electrophysiological measures of synaptic potentiation . Changes in spine density and / or head diameter ( d h ) are a struc - tural substrate for synaptic plasticity , with larger d h being asso - ciated with LTP and reduced d h with LTD ( Carlisle and Kennedy , 2005 ; De Roo et al . , 2008 ; Yang and Zhou , 2009 ) . Consistent with previous reports ( Kourrich et al . , 2007 ; Moussawi et al . , 2011 ; Shen et al . , 2009 ) , withdrawal from investigator - or self - adminis - tered cocaine increased d h and A / N compared to yoked - saline rats . The d h and A / N were further increased 15 min after initiating cue - induce"
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