Recent research in instrumental conditioning has focused on the striatum, particularly the role of the dorsal striatum in the learning processes that contribute to instrumental performance in rats. This research has found evidence of what appear to be parallel, functionally and anatomically distinct circuits involving dorsomedial striatum (DMS) and dorsolateral striatum (DLS) that contribute to...

Organizing movements in time is a critical and highly conserved feature of mammalian behavior. Temporal control of action requires corticostriatal networks. We investigate these networks in rodents using a two-interval timing task while recording LFPs in medial frontal cortex (MFC) or dorsomedial striatum. Consistent with prior work, we found cue-triggered delta (1-4 Hz) and theta activity (4-8...

Reward learning plays a central role in decision making and adaptation. Accumulating evidence suggests that the striatum contributes enormously to reward learning but that its subregions may have distinct functions. A recent article by Tricomi and Lempert (J Neurophysiol. First published 22 October 2014, doi:10.1152/jn.00086.2014.) found that ventral striatum tracks reward value, whereas dorsol...

While dopamine input to the dorsal striatum is well-known to be critical for action selection, including alcohol-motivated behaviors, it is unknown whether changes in phasic dopamine accompany these behaviors. Long-term alcohol abuse is believed to promote alterations in the neurocircuitry of reward learning in both ventral and dorsal striatum, potentially through increasing dopamine release. U...

In mammals, the dorsomedial striatum is one brain area shown to be critical for the flexible shifting of response patterns. At present, the neurochemical mechanisms that underlie learning during a shift in response patterns are unknown. The present study examined the effects of NMDA competitive antagonist, DL-2-amino-5-phosphonopentanoic acid (AP-5), injected into the dorsomedial striatum on th...

Context-induced reinstatement of drug seeking is a well established animal model for assessing the neural mechanisms underlying context-induced drug relapse, a major factor in human drug addiction. Neural activity in striatum has previously been shown to contribute to context-induced reinstatement of heroin, cocaine, and alcohol seeking, but not yet for methamphetamine seeking. In this study, w...

Striatal adenosine A2A receptors (A2ARs) modulate striatal synaptic plasticity and instrumental learning, possibly by functional interaction with the dopamine D2 receptors (D2Rs) and metabotropic glutamate receptors 5 (mGluR5) through receptor-receptor heterodimers, but in vivo evidence for these interactions is lacking. Using in situ proximity ligation assay (PLA), we studied the subregional d...

Dopaminergic medication in Parkinson's disease has been proposed to improve cognitive processing by modulating the severely depleted dorsal striatum, while impairing reward processing by modulating the relatively intact ventral striatum. However, there is no direct (neural) evidence for this hypothesis. Here we fill this gap by scanning Parkinson's disease patients (n=15) ON and relatively OFF ...

Acetylcholine is one of the major neurotransmitters in the brain. The highest density of cholinergic markers is found in the striatum, a basal ganglia region that has been associated with behavioral flexibility. In our recent study, we showed a causal role of the cholinergic interneurons of the striatum in set-shifting in the rat. The set-shifting task required an attentional shift from one sti...