PBN-PVT projection modulates negative affective states in mice

Abstract

Negative emotions can be described as feelings that cause us to be miserable and sad. Long-lasting negative emotions dampen enthusiasm for life; thus, dealing with negative emotions is essential for individual survival. The parabrachial nucleus (PBN) and the thalamic paraventricular nucleus (PVT) are critical for modulating affections in mice. However, the functional role of the projection from the PBN to the PVT in affection modulation remains elusive. Here, we show that the PBN neurons send dense projection fibers to the PVT and form direct excitatory synapses with the PVT neurons. Activation of the PBN-PVT projections or PVT-projecting PBN neurons induces robust anxiety-like and fear-like behaviors without affecting depression-like and nociceptive behaviors. Inhibition of the PVT-projecting PBN neurons relieves fear-like and aversion-like behaviors. Furthermore, the PVT neurons innervated by the PBN were activated in negative experiences, and activation of these neurons induced anxiety-like behavior. Thus, our study indicates that the PBN-PVT projection modulates negative emotions in mice.