Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Pittsburgh Center for Pain Research, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Neuron. 2020 Jun 17;106(6):927-939.e5. doi: 10.1016/j.neuron.2020.03.014. Epub 2020 Apr 13.
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.
外侧臂旁核（lPBN）是将伤害性传入信息传递到脊髓以上结构的脊髓投射神经元的主要靶点。然而，不同 lPBN 传出纤维在各种伤害性反应中的功能作用在很大程度上仍未得到阐明。在这里，我们表明 lPBN 是逃避行为和对有害刺激的厌恶学习所必需的。此外，我们发现来自 lPBN 不同区域的两种传出神经元群体向不同的靶位侧支化。激活到腹内侧下丘脑（VMH）或外侧导水管周围灰质（lPAG）的传出投射驱动逃避行为，而激活到终纹床核（BNST）或中央杏仁核（CEA）的 lPBN 传出纤维则产生厌恶记忆。最后，我们提供的证据表明，dynorphin 表达神经元，其跨越 lPBN 的细胞构筑不同区域，是厌恶学习所必需的。
