title: Dynamic encoding of action selection by the medial striatum.
abstract: Successful foragers respond flexibly to environmental stimuli. Behavioral flexibility depends on a number of brain areas that send convergent projections to the medial striatum, such as the medial prefrontal cortex, orbital frontal cortex, and amygdala. Here, we tested the hypothesis that neurons in the medial striatum are involved in flexible action selection, by representing changes in stimulus-reward contingencies. Using a novel Go/No-go reaction-time task, we changed the reward value of individual stimuli within single experimental sessions. We simultaneously recorded neuronal activity in the medial and ventral parts of the striatum of rats. The rats modified their actions in the task after the changes in stimulus-reward contingencies. This was preceded by dynamic modulations of spike activity in the medial, but not the ventral, striatum. Our results suggest that the medial striatum biases animals to collect rewards to potentially valuable stimuli and can rapidly influence flexible behavior.
authors.affiliation: The John B. Pierce Laboratory, New Haven, Connecticut 06519, USA.
authors.forename: Eyal Yaacov
authors.initials: EY
authors.lastname: Kimchi
authors.forename: Mark
authors.initials: M
authors.lastname: Laubach
mesh_terms: D000818:Animals; D001479:Basal Ganglia / Q000502:physiology; D003216:Conditioning, Operant / Q000502:physiology; D003342:Corpus Striatum / Q000502:physiology*; D004193:Discrimination Learning / Q000502:physiology*; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D011930:Reaction Time / Q000502:physiology; D012201:Reward