SatB2-Expressing Neurons in the Parabrachial Nucleus Encode Sweet Taste.

The gustatory system plays an important role in sensing appetitive and aversive tastes for evaluating food quality. In mice, taste signals are relayed by multiple brain regions, including the parabrachial nucleus (PBN) of the pons, before reaching the gustatory cortex via the gustatory thalamus. Recent studies show that taste information at the periphery is encoded in a labeled-line manner, such that each taste modality has its own receptors and neuronal pathway. In contrast, the molecular identity of gustatory neurons in the CNS remains unknown. Here, we show that SatB2-expressing neurons in the PBN play a pivotal role in sweet taste transduction. With cell ablation, in vivo calcium imaging, and optogenetics, we reveal that SatB2^PBN neurons encode positive valance and selectively transmit sweet taste signals to the gustatory thalamus. • Loss of SatB2^PBN neurons lead to selective impairment of sweet taste sensing • SatB2^PBN neurons respond to sweet taste but not to other tastes • Optogenetic activation of SatB2^PBN neurons enhances water lick behavior • The gustatory thalamus-projecting SatB2^PBN neurons encode positive valance While the molecular mechanism of peripheral taste system has been extensively investigated, the molecular identity of gustatory neurons in the CNS remains unknown. Fu et al. demonstrate that SatB2-expressing neurons in the mouse parabrachial nucleus encode positive valence and selectively transmit sweet taste signals to the gustatory thalamus. [ABSTRACT FROM AUTHOR]