title: Invigoration of reward seeking by cue and proximity encoding in the nucleus accumbens.
abstract: A key function of the nucleus accumbens is to promote vigorous reward seeking, but the corresponding neural mechanism has not been identified despite many years of research. Here, we study cued flexible approach behavior, a form of reward seeking that strongly depends on the accumbens, and we describe a robust, single-cell neural correlate of behavioral vigor in the excitatory response of accumbens neurons to reward-predictive cues. Well before locomotion begins, this cue-evoked excitation predicts both the movement initiation latency and the speed of subsequent flexible approach responses, but not those of stereotyped, inflexible responses. Moreover, the excitation simultaneously signals the subject's proximity to the approach target, a signal that appears to mediate greater response vigor on trials that begin with the subject closer to the target. These results demonstrate a neural mechanism for response invigoration whereby accumbens neuronal encoding of reward availability and target proximity together drive the onset and speed of reward-seeking locomotion.
authors.affiliation: Department of Psychiatry, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY 10461, USA.
authors.forename: Vincent B
authors.initials: VB
authors.lastname: McGinty
authors.forename: Sylvie
authors.initials: S
authors.lastname: Lardeux
authors.forename: Sharif A
authors.initials: SA
authors.lastname: Taha
authors.forename: James J
authors.initials: JJ
authors.lastname: Kim
authors.forename: Saleem M
authors.initials: SM
authors.lastname: Nicola
mesh_terms: D000161:Acoustic Stimulation; D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001931:Brain Mapping; D003216:Conditioning, Operant / Q000502:physiology*; D003463:Cues; D004192:Discrimination, Psychological; D004567:Electrodes, Implanted; D007839:Functional Laterality; D008124:Locomotion / Q000502:physiology; D008954:Models, Biological; D009474:Neurons / Q000502:physiology*; D009714:Nucleus Accumbens / Q000166:cytology / Q000502:physiology*; D009949:Orientation; D025341:Principal Component Analysis; D051381:Rats; D011930:Reaction Time / Q000502:physiology; D012201:Reward; D014743:Videotape Recording