Modulation of forebrain function by nucleus incertus and relaxin-3/RXFP3 signaling

Abstract

The nucleus incertus (NI) in the pontine tegmentum sends ascending projections to the midbrain, hypothalamus, amygdala, basal forebrain, hippocampus, and prefrontal cortex, and has a postulated role in modulating several forebrain functions. A substantial population of GABAergic NI neurons expresses the neuropeptide, relaxin-3, which acts via the G i/o -protein-coupled receptor, RXFP3, present throughout the forebrain target regions. Broad and specific manipulations of these systems by activation or inhibition of the NI or modulating RXFP3 signaling have revealed key insights into the likely influence of the NI/relaxin-3/RXFP3 system on modalities including arousal, feeding, stress responses..