Linking Memories across Time via Neuronal and Dendritic Overlaps in Model Neurons with Active Dendrites.
Cell Rep 2017;
17:1491-1504. [PMID:
27806290 PMCID:
PMC5149530 DOI:
10.1016/j.celrep.2016.10.015]
[Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/17/2016] [Accepted: 10/04/2016] [Indexed: 11/29/2022] Open
Abstract
Memories are believed to be stored in distributed neuronal assemblies through activity-induced changes in synaptic and intrinsic properties. However, the specific mechanisms by which different memories become associated or linked remain a mystery. Here, we develop a simplified, biophysically inspired network model that incorporates multiple plasticity processes and explains linking of information at three different levels: (1) learning of a single associative memory, (2) rescuing of a weak memory when paired with a strong one, and (3) linking of multiple memories across time. By dissecting synaptic from intrinsic plasticity and neuron-wide from dendritically restricted protein capture, the model reveals a simple, unifying principle: linked memories share synaptic clusters within the dendrites of overlapping populations of neurons. The model generates numerous experimentally testable predictions regarding the cellular and sub-cellular properties of memory engrams as well as their spatiotemporal interactions.
Network model with active dendrites and synaptic, somatic, homeostatic plasticity
Linked memories are stored in overlapping populations of neurons
Linked memories share synaptic clusters in common dendritic branches
The locus of protein synthesis or capture shapes the structure of the memory trace
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