Dorsal raphe neurons signal reward through 5-HT and glutamate.

TitleDorsal raphe neurons signal reward through 5-HT and glutamate.
Publication TypeJournal Article
Year of Publication2014
AuthorsLiu Z, Zhou J, Li Y, Hu F, Lu Y, Ma M, Feng Q, Zhang J-E, Wang D, Zeng J, Bao J, Kim J-Y, Chen Z-F, Mestikawy SEl, Luo M
Date Published2014 Mar 19
KeywordsAnimals, Behavior, Animal, Glutamic Acid, Mesencephalon, Mice, Mice, Inbred C57BL, Mice, Transgenic, Neurons, Raphe Nuclei, Reward, Serotonin

The dorsal raphe nucleus (DRN) in the midbrain is a key center for serotonin (5-hydroxytryptamine; 5-HT)-expressing neurons. Serotonergic neurons in the DRN have been theorized to encode punishment by opposing the reward signaling of dopamine neurons. Here, we show that DRN neurons encode reward, but not punishment, through 5-HT and glutamate. Optogenetic stimulation of DRN Pet-1 neurons reinforces mice to explore the stimulation-coupled spatial region, shifts sucrose preference, drives optical self-stimulation, and directs sensory discrimination learning. DRN Pet-1 neurons increase their firing activity during reward tasks, and this activation can be used to rapidly change neuronal activity patterns in the cortex. Although DRN Pet-1 neurons are often associated with 5-HT, they also release glutamate, and both neurotransmitters contribute to reward signaling. These experiments demonstrate the ability of DRN neurons to organize reward behaviors and might provide insights into the underlying mechanisms of learning facilitation and anhedonia treatment.

Alternate JournalNeuron
PubMed ID24656254
PubMed Central IDPMC4411946
Grant ListAR056318 / AR / NIAMS NIH HHS / United States
R01 AR056318 / AR / NIAMS NIH HHS / United States