Noxious stimulus

Dynorphin

Nociception

Neuroscience

Receptor

Central nucleus of the amygdala

Pons

Afferent

Nucleus

Periaqueductal gray

Central nervous system

Midbrain

Biology

Opioid peptide

Psychology

Efferent

Stimulation

Stria terminalis

Lateral parabrachial nucleus

Septal nuclei

Opioid

Amygdala

Parabrachial Nucleus

Biochemistry

Neuron

The lateral parabrachial nucleus (lPBN) is a major target of spinal projection neurons conveying nociceptive input into supraspinal structures. However, the functional role of distinct lPBN efferents in diverse nocifensive responses have remained largely uncharacterized. Here we show that that the lPBN is required for escape behaviors and aversive learning to noxious stimulation. In addition, we find that two populations of efferent neurons from different regions of the lPBN collateralize to distinct targets. Activation of efferent projections to the ventromedial hypothalamus (VMH) or lateral periaqueductal gray (lPAG) drives escape behaviors, whereas activation of lPBN efferents to the bed nucleus stria terminalis (BNST) or central amygdala (CEA) generates an aversive memory. Finally, we provide evidence that dynorphin-expressing neurons, which span cytoarchitecturally distinct domains of the lPBN, are required for aversive learning.

Divergent Neural Pathways Emanating from the Lateral Parabrachial Nucleus Mediate Distinct Components of the Pain Response