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The Double-H Maze: A Robust Behavioral Test for Learning and Memory in Rodents
Published on: July 8, 2015
Experience reorganizes content-specific memory traces in macaques
Saman Abbaspoor1,2,3,4, Ayman Aljishi5, Kari L Hoffman6,7
1Department of Psychology, Vanderbilt Vision Research Center, Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA. sam.abbaspoor@childrens.harvard.edu.
Nature Neuroscience
|July 29, 2026
Summary
Neural assemblies stabilize with memory age, showing less drift and stronger reactivation during sleep. This suggests mechanisms for balancing new learning with memory durability in the primate brain.
Area of Science:
- Neuroscience
- Cognitive Science
- Memory Research
Background:
- Memory formation involves neural reorganization during experience and sleep.
- The interplay between learning new information and preserving existing memories is not fully understood.
Purpose of the Study:
- To investigate how neural activity patterns change with memory age in the primate brain.
- To explore mechanisms balancing memory consolidation and the formation of new memories.
Main Methods:
- Recorded neural ensemble activity in hippocampal and associated regions of freely moving macaques.
- Analyzed cell assemblies associated with 'new', 'recent', and 'old' item sequences.
- Examined network connectivity, sleep reactivation, and long-term interactions of neural assemblies.
Main Results:
- Older memory-associated cell assemblies exhibited less drift, enhanced network connectivity, and stronger sleep reactivation compared to newer ones.
- Persistent task-to-sleep coupling ('metassemblies') formed between old and recent assemblies, with longer interactions over time.
- Increased integration of superficial and deep CA1 pyramidal cells into assemblies correlated with memory age.
Conclusions:
- Neural activity rapidly organizes and stabilizes in the primate brain as memories age.
- These findings propose mechanisms for balancing the integration of new learning with the durability of established memories.
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