H T Cline

..These studies indicate that impaired neuronal growth may be responsible in part for lead-induced cognitive deficits and that chelator treatment counteracts this effect...

..These findings, together with data indicating that the genes encoding neuroligin and PSD95 are altered in autism patients, suggest that a molecular understanding of complex neurological diseases is within reach...

..The different roles of synaptic activity with respect to structural plasticity probably reflect the regulated spatiotemporal expression of key components within signaling pathways...

..Newly formed synapses may be silent unless sufficient depolarization is provided by coincident activity that could activate postsynaptic CaMKII, resulting in the appearance of AMPA responses...

..CPG15 may represent a new class of activity-regulated, membrane-bound, growth-promoting proteins that permit exquisite spatial and temporal control of neuronal structure...

..These data support a model in which CPG15 expressed in retinal ganglion cells is trafficked to retinal axons, where it modulates postsynaptic dendritic arbor elaboration, and synaptic maturation...

..This technique will allow unprecedented spatial and temporal control over gene delivery and protein expression...

..This single molecular interaction appears to initiate clustering of synaptic vesicles, assembly of vesicle-release machinery and morphological changes at the presynaptic membrane...

..This debate is presented simplistically here in terms of Sperry's chemoaffinity hypothesis versus Hebb's rules of correlation-based synaptic change, which are often presented as being mutually exclusive - much like oil and vinegar...

....

..The ubiquitin-proteasome system regulates protein degradation in every eukaryotic cell. Recent work has shown that protein turnover mediated by the ubiquitin-proteasome system plays a key role in synaptic plasticity...

..The high level of conservation of the xhomer1 gene and the protein expression in the developing nervous system suggest that Homer1 expression may be important for normal neuronal circuit development...

..This is the first evidence that mGluR-mediated changes in AMPA transmission can be regulated by Homer proteins in response to physiologically relevant stimuli...

..These results indicate that AMPAR-mediated transmission underlies experience-dependent dendritic arbor growth by stabilizing branches, and support a competition-based model for dendrite growth...

..Our results demonstrate that Arc/Arg3.1 reduces the number of GluR2/3 receptors leading to a decrease in AMPAR-mediated synaptic currents, consistent with a role in the homeostatic regulation of synaptic strength...

..This suggests that in vivo visual stimulation increases synapses that have a low Pr and that have properties consistent with immature synapses...

..The results indicate that the delivery of the neurotrophic protein CPG15 to the axon surface can be regulated on a rapid time scale by activity-dependent mechanisms in vivo...

..Single-cell electroporation is an affordable method to fluorescently label and genetically manipulate individual cells. This powerful technique enables observation of single cells in an otherwise normal environment...

..CPG15 expression enhances the development of motor neuron axon arbors by promoting neuromuscular synaptogenesis and by increasing the addition of new axon branches...

..These data indicate that insulin receptor signaling regulates circuit function and plasticity by controlling synapse density...

..These data suggest a link between glutamate receptor function, Rho GTPase activity, and dendritic arbor growth in the intact animal...

....

..The Rho GTPases have emerged as key integrators of these environmental cues to regulate the underlying dendritic cytoskeleton...

..These experiments indicate that NR2A and NR2B have subunit-specific properties in dendritic arbor development, but also overlapping functions, indicating a requirement for both subunits in neuronal development...

..Regulation of polyamine synthesis by physiological stimuli is a novel form of modulation of synaptic transmission important for understanding the short-term effects of enhanced sensory experience during development...

....

..The results delineate a role for Rho GTPases in the structural plasticity driven by visual stimulation in vivo...

..Because the majority of synaptic contacts are formed on dendrites, the structural changes we observed in interneuronal dendritic arbors suggest that optic tectal circuits are extremely plastic during early stages of development...

..These results describe a correlation-based mechanism by which visual experience directly governs axon branch dynamics that contribute to the development of topographic maps...

..The synaptic and intrinsic adaptations function together to keep tectal neurons within a constant operating range, while making the intact visual system less responsive to background activity yet more sensitive to burst stimuli...

..Therefore, depolarizing GABAergic transmission plays a pivotal role in the maturation of excitatory transmission and controls the balance of excitation and inhibition in the developing retinotectal circuit...

..Visual stimulation for 4 h enhanced the stability of the arbor at intense presynaptic puncta while concurrently inducing the retraction of exploratory branches with only faintly labeled or no synaptic sites...

..Finally, we review recent experiments in other CNS projections that support the proposition that cooperation between molecular guidance cues and activity-dependent processes constitutes a general paradigm for CNS map formation...