The globus pallidus sends reward-related signals to the lateral habenula.
As a major output station of the basal ganglia, the globus pallidus internal segment (GPi) projects to the thalamus and brainstem nuclei thereby controlling motor behavior. A less well known fact is that the GPi also projects to the lateral habenula (LHb) which is often associated with the limbic system. Using the monkey performing a saccade task with positionally biased reward outcomes, we found that antidromically identified LHb-projecting neurons were distributed mainly in the dorsal and ventral borders of the GPi and that their activity was strongly modulated by expected reward outcomes. A majority of them were excited by the no-reward-predicting target and inhibited by the reward-predicting target. These reward-dependent modulations were similar to those in LHb neurons but started earlier than those in LHb neurons. These results suggest that GPi may initiate reward-related signals through its effects on the LHb, which then influences the dopaminergic and serotonergic systems.
Hong
Simon
S
Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, 49 Convent Drive, Bethesda, MD 20892, USA.
Hikosaka
Okihide
O
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D015982:Bias; D001679:Biogenic Amines / Q000378:metabolism; D004644:Emotions / Q000502:physiology; D005917:Globus Pallidus / Q000033:anatomy & histology / Q000502:physiology*; D019262:Habenula / Q000033:anatomy & histology / Q000502:physiology*; D008032:Limbic System / Q000033:anatomy & histology / Q000502:physiology; D008253:Macaca mulatta; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D009483:Neuropsychological Tests; D012054:Reinforcement, Psychology; D012201:Reward; D012438:Saccades / Q000502:physiology
D001679:Biogenic Amines