G G Turrigiano

..On a functional level, neuronal networks likely use this complex set of regulatory mechanisms to achieve homeostasis over a wide range of temporal and spatial scales...

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..These advances significantly broaden our framework for understanding the effects of activity on synaptic function and neuronal excitability...

..Additional mechanisms may allow local or network-wide changes in activity to be sensed through parallel pathways, generating a nested set of homeostatic mechanisms that operate over different temporal and spatial scales...

..In addition to provide insight into the mechanisms of homeostatic plasticity, these data argue for the first time for an equal partnership between glial cells and neurons in the generation of an important form of synaptic plasticity...

..A recent study in Ceanorhabditis elegans suggests that ubiquitination of AMPA receptors is one important signal that targets these receptors for endocytosis...

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..Together, these data suggest that TNF? is not an instructive signal for scaling but rather is critical for maintaining synapses in a plastic state in which synaptic scaling can be expressed...

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..These data suggest that postsynaptic activation of CaMKII induces a structural remodeling of presynaptic inputs that favors the retention of active presynaptic partners...

..A fundamental challenge for the field is to assemble our detailed knowledge of these specific mechanisms into a coherent picture of how plasticity within cortical circuits works to tune network properties...

..Together, our results suggest that synaptic scaling and LTP use different trafficking pathways, making these two forms of plasticity both functionally and molecularly distinct...

..These data suggest that correlated high-frequency firing at layer-5 synapses simultaneously induces a mixture of presynaptic LTD, presynaptic LTP, and postsynaptic LTP...

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..The proposed mode of propagation allows for fast computation with population coding based on firing rates, as is demonstrated with a local motion detector...

..This may ensure that LTP does not alter the relative contributions of these two receptors to synaptic transmission and information processing...

..The results hold important implications for which parts of the neural code are most readily stored for later retrieval...

..These forms of homeostatic plasticity are likely to go 'hand-in-glove' with Hebbian mechanisms to allow experience to modify the properties of neuronal networks selectively...

..Our data suggest that activating CaMKII can increase synaptic connectivity through a CaM-dependent increase in contact formation, followed by stabilization of a constant fraction of new contacts...

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..Because excitatory and inhibitory synaptic currents are regulated in opposite directions by activity blockade, these data suggest that the balance between excitation and inhibition is dynamically regulated by ongoing activity...

..The existence of multiple, partially redundant forms of homeostatic plasticity may ensure that network compensation can be achieved in response to a wide range of sensory perturbations...

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..This suggests that LTP-IE occurs through postsynaptic calcium influx and subsequent activation of PKA. Activity-dependent plasticity in intrinsic excitability could greatly expand the computational power of individual neurons...

..We conclude that this basic property of excitatory transmission is conserved across PFC and VC synapses and is therefore unlikely to contribute to differences in firing patterns observed in vivo in the two regions...

..Inhibitory plasticity is thus fundamental in modulating cortical circuit refinement and might be one of the mechanisms promoting ocular dominance shifts...

..These findings provide the first detailed electrophysiological analysis of Mecp2-mutant mice and provide a framework for understanding the pathophysiology of the disease and tools for studying the underlying disease mechanisms...

..These effects reversed when vision was restored. This dynamic adjustment of the excitation-inhibition balance may allow the networks within layer 4 to maintain stable levels of activity in the face of variable sensory input...

..Our data indicate that TrkB isoform expression can be selectively regulated by visual experience, and may contribute to experience-dependent cortical plasticity...

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..In addition to generating important mechanistic insights into activity-dependent plasticity, these experiments will test some fundamental assumptions about the function of synaptic scaling. ..

..In addition to generating important mechanistic insights into activity-dependent plasticity, these experiments will test some fundamental assumptions about the function of synaptic scaling. ..

..Ultimately, these studies will illuminate the genesis of aberrant states, such as addiction or epilepsy that involve adaptive plasticity and/or imbalances in synaptic excitation and inhibition. ..

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..We are requesting support to fund the attendance of underrepresented groups in the field of Neural Circuit plasticity, including women and ethnic minorities. ..

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..In addition to the user group, the confocal/multiphoton facility will be available to all life science researchers at Brandeis who have a need for this technology on a time-available basis. ..

..Understanding the mechanisms that promote stability in cortical networks will allow us to understand how these processes may go awry in disease states such as epilepsy. ..

..Ultimately, these studies will illuminate the genesis of aberrant states, such as addiction or epilepsy that involve adaptive plasticity and/or imbalances in synaptic excitation and inhibition. ..