![]() ![]() ![]() ![]() In contrast, most spines in hippocampal area CA1 seem to be transient with a mean lifetime of ~10 days ( Attardo et al. In cortex, most spines appear to be relatively stable once the critical period is over ( Attardo et al. The reported degree of spine turnover in adult mice varies considerably by brain area. Dendritic spines in adult mammals can be eliminated or grow in new locations ( Grutzendler et al. In mammals, dendritic spines are the major sites of excitatory synapses ( Nimchinsky et al. Synapses are sites of communication between neurons. Our results suggest that memory can be stored in the correlation structure of a network undergoing rapid synaptic remodeling. We show that Hebbian plasticity of synaptic strengths during reactivation events can preserve memory in computational models of hippocampal and cortical networks despite turnover of all synapses. NEW & NOTEWORTHY Recent research suggests that synapses turn over rapidly in some brain structures however, memories seem to persist for much longer. Together, these data suggest that a simple plasticity rule, correlative Hebbian plasticity of synaptic strengths, is sufficient to preserve neural representations in the face of synapse turnover, even in the absence of activity-dependent structural plasticity. Furthermore, we find that Hebbian plasticity during replay is sufficient to stabilize the receptive fields of hippocampal place cells in a model of the grid-cell-to-place-cell transformation in CA1 and of orientation-selective cells in a model of the center-surround-to-simple-cell transformation in V1. We demonstrate that Hebbian plasticity during replay of presynaptic activity patterns can integrate newly formed synapses into pre-existing memories. Here, we use computational modeling to ask how memories can persist in neural circuits such as the hippocampus and visual cortex in the face of synapse turnover. If this is true, and if turnover is equally likely for all spines, ~95% of excitatory synapses onto a particular neuron will turn over within 30 days however, a neuron’s receptive field can be relatively stable over this period. For example, recent research suggests that dendritic spines in the adult mouse hippocampus are transient with an average lifetime of ~10 days. The mapping on this website is provided by external mapping providers and is for general information purposes only.Our brains must maintain a representation of the world over a period of time much longer than the typical lifetime of the biological components producing that representation. Please contact your local authorized Land Rover Retailer for availability and prices. Some vehicles are shown with optional equipment and retailer-fit accessories that may not be available in all markets. The information, specification, engines and colors on this website are based on European specifications and may vary from market to market and are subject to change without notice. Some features may vary between optional and standard for different model year vehicles. Jaguar Land Rover Limited is constantly seeking ways to improve the specification, design and production of its vehicles, parts, options and/or accessories and alterations take place continually, and we reserve the right to make changes without notice. This is a very dynamic situation, and as a result imagery used within the website at present may not fully reflect current specifications for features, options, trim and color schemes. Please contact your local authorized Land Rover Retailer for detailed specifications. The global shortages of semiconductors and other materials are currently affecting vehicle build specifications, option availability, and build timings. Important note on imagery & specifications. © 2023 Jaguar Land Rover North America, LLC ![]()
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