Building Neural Representations of Habits

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.

Regional Differences in Extracellular Dopamine and Serotonin Assessed by In Vivo Microdialysis in Mice Lacking Dopamine and/or Serotonin Transporters

“…These structures can be critical for stimulus-response 'habit' learning, including that related to reward (Jog et al, 1999;Reynolds et al, 2001). It is conceivable that this structure may play an even greater role in DAT-KO mice that lack cocaine-induced DA ex elevations in NAc.…”

Dietary supplementation with uridine-5′-monophosphate (UMP), a membrane phosphatide precursor, increases acetylcholine level and release in striatum of aged rat

“…Since the levels of ACh in striatal dialysates are much higher and more readily measured than those in hippocampal or cortical dialysates (Wu et al, 1988), and since the UMP-induced rise in brain phosphatides may mediate the increase in ACh, we collected ECF (dialysis) samples from striatum for these studies. Striatal neurons are involved in various types of learning in rats (e.g., stimulus-response habits as well as motor, perceptual, and cognitive skills) (Jog et al, 1999), and cholinergic interneurons modulate these neuronal circuits (Kaneko et al, 2000). Microdialysis studies have shown that when rats used response strategies rather than spatial strategies for learning, striatal ACh release increased (Chang et al, 2003).…”

Comparison of population activity in the dorsal premotor cortex and putamen during the learning of arbitrary visuomotor mappings

“…Antecedents can include visual and other sensory inputs, and consequents usually involve movements or the targets of movement. Changes in task-related neuronal activity during arbitrary visuomotor learning have been described for dorsal premotor cortex (PMd) (Mitz et al, 1991;Brasted and Wise, 2004), supplementary eye field (Chen and Wise, 1995a, b), frontal eye field (Chen and Wise, 1995b), prefrontal cortex (Asaad et al, 1998;Pasupathy and Miller, 2005), hippocampus (Cahusac et al, 1993;Wirth et al, 2003), striatum Jog et al, 1999;Brasted and Wise, 2004;Pasupathy and Miller, 2005) and globus pallidus (Inase et al, 2001). Neuropsychological studies point to the same neural network (Petrides, 1985;Halsband and Passingham, 1985;Rupniak and Gaffan, 1987;Gaffan and Harrison, 1988;Canavan et al, 1989;Eacott and Gaffan, 1992;Murray and Wise, 1996;Ridley and Baker, 1997;Wang et al, 2000;Bussey et al, 2001Bussey et al, , 2002Brasted et al, 2002Brasted et al, , 2003Barefoot et al, 2002Barefoot et al, , 2003Nixon et al, 2004), as does the neuroimaging literature (Deiber et al, 1991(Deiber et al, , 1997Paus et al, 1993;Toni and Passingham, 1999;Toni et al, 2001Toni et al, , 2002Eliassen et al, 2003).…”