Linking Memories across Time via Neuronal and Dendritic Overlaps in Model Neurons with Active Dendrites

• DOI: 10.1016/j.celrep.2016.10.015
• Publication Date: 2016-11-01T16:32:06Z
• Authors: George Kastellakis; Alcino J. Silva; Panayiota Poirazi
• Keywords: 0303 health sciences; Neuronal Plasticity; Time Factors; QH301-705.5; Models, Neurological; synaptic tagging and capture; Action Potentials; Nerve Tissue Proteins; Dendrites; non-linear dendrites; intrinsic excitability; information binding; Article; computational model; 03 medical and health sciences; simplified neurons; Memory; plasticity; memory allocation; Biology (General); Nerve Net; synaptic clustering; Subcellular Fractions

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.