Building Neural Representations of Habits

TLDR

Habit and skill memories are formed in distinct brain systems and are differentially affected by neurodegenerative disorders. The study recorded chronic activity from striatal neuron ensembles with multiple tetrodes while rats learned a T‑maze procedural task. During habit learning, sensorimotor striatal activity reorganized, showing widespread changes that became task‑specific at the start and end of the procedure and remained stable over weeks of repeated performance.

Abstract

Memories for habits and skills (“implicit or procedural memory”) and memories for facts (“explicit or episodic memory”) are built up in different brain systems and are vulnerable to different neurodegenerative disorders in humans. So that the striatum-based mechanisms underlying habit formation could be studied, chronic recordings from ensembles of striatal neurons were made with multiple tetrodes as rats learned a T-maze procedural task. Large and widely distributed changes in the neuronal activity patterns occurred in the sensorimotor striatum during behavioral acquisition, culminating in task-related activity emphasizing the beginning and end of the automatized procedure. The new ensemble patterns remained stable during weeks of subsequent performance of the same task. These results suggest that the encoding of action in the sensorimotor striatum undergoes dynamic reorganization as habit learning proceeds.