Hebbian plasticity in parallel synaptic pathways: A circuit mechanism for systems memory consolidation

Area of Science:

• Neuroscience
• Cognitive Science
• Computational Neuroscience

Background:

• Systems memory consolidation involves memory transfer and transformation across brain regions.
• Declarative memories shift from the hippocampus to neocortex; procedural memories consolidate within cortico-striatal networks.
• Cellular and network mechanisms of memory consolidation, relying on replay and repetition, remain poorly understood.

Purpose of the Study:

• To propose and investigate Hebbian plasticity in networks with parallel synaptic pathways as a mechanism for systems memory consolidation.
• To explore how this mechanism facilitates memory transfer and representational changes in hippocampus-dependent memories.
• To bridge cellular and network scales with short and long timescales in memory consolidation.

Main Methods:

• Computational modeling and mathematical analysis of neural circuits with parallel pathways.
• Testing the hypothesis in the context of hippocampus-dependent memory consolidation.
• Comparing model predictions with existing lesion studies in rodents and psychophysical data in humans.

Main Results:

• Hebbian plasticity in parallel pathways can mediate memory transfer by creating a linear approximation of the memory in a new pathway.
• Modeling results quantitatively align with rodent lesion studies.
• A hierarchical application of the proposed mechanism explains power-law forgetting observed in human studies.

Conclusions:

• Hebbian plasticity within parallel synaptic pathways provides a unified mechanism for systems memory consolidation.
• This mechanism explains memory transfer, representational transformation, and long-term forgetting across multiple timescales.
• The model bridges cellular, network, and systems levels of memory processing.