Genetic identity of thermosensory relay neurons in the lateral parabrachial nucleus
Genetic identity of thermosensory relay neurons in the lateral parabrachial nucleus
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DOI：
10.1152/ajpregu.00094.2015
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发表时间：
2016-01-01
影响因子：
2.8
通讯作者：
Scammell, Thomas E.
中科院分区：
文献类型：
--
作者：
Geerling, Joel C.;Kim, Minjee;Scammell, Thomas E.
臂旁核对体温调节很重要，因为它将皮肤温度信息从脊髓传递到下丘脑。先前对大鼠的研究将热感觉中继神经元定位于其外侧分支（LPB），但这些神经元的遗传和神经化学特性仍不清楚。为了确定LPB热感觉神经元的身份，我们将小鼠暴露在温暖（36摄氏度）或凉爽（4摄氏度）的环境温度中。每种情况都激活了接收脊髓输入的不同LPB亚区的神经元。这些LPB亚区中的大多数c-Fos+神经元表达转录因子标记物FoxP2。与先前的证据一致，LPB热感觉中继神经元是谷氨酸能的，在Vglut2报告小鼠中，这些亚区域的所有FoxP2+神经元都与绿色荧光蛋白（GFP）共定位，而不是与Vgat共定位。用GFP报告小鼠鉴定了表达前啡肽（Pdyn）的神经元，并形成了LPB FoxP2+神经元的尾侧亚群，主要位于背侧亚核（PBdL）。温暖暴露激活了PBdL内的许多FoxP2+神经元。PBdL中一半的c-Fos+神经元为Pdyn+，且大部分投射到视前区。低温暴露激活了远吻侧LPB中一个单独的FoxP2+神经元簇，我们将其命名为喙侧-外外侧亚核（PBreL）。这些发现提高了我们对LPB组织的理解，并揭示了Pdyn-IRES-Cre小鼠提供了PBdL中温暖激活的FoxP2+谷氨酸能神经元的遗传通路，其中许多神经元映射到下丘脑。
The parabrachial nucleus is important for thermoregulation because it relays skin temperature information from the spinal cord to the hypothalamus. Prior work in rats localized thermosensory relay neurons to its lateral subdivision (LPB), but the genetic and neurochemical identity of these neurons remains unknown. To determine the identity of LPB thermosensory neurons, we exposed mice to a warm (36 degrees C) or cool (4 degrees C) ambient temperature. Each condition activated neurons in distinct LPB subregions that receive input from the spinal cord. Most c-Fos+ neurons in these LPB subregions expressed the transcription factor marker FoxP2. Consistent with prior evidence that LPB thermosensory relay neurons are glutamatergic, all FoxP2+ neurons in these subregions colocalized with green fluorescent protein (GFP) in reporter mice for Vglut2, but not for Vgat. Prodynorphin (Pdyn)-expressing neurons were identified using a GFP reporter mouse and formed a caudal subset of LPB FoxP2+ neurons, primarily in the dorsal lateral subnucleus (PBdL). Warm exposure activated many FoxP2+ neurons within PBdL. Half of the c-Fos+ neurons in PBdL were Pdyn+, and most of these project into the preoptic area. Cool exposure activated a separate FoxP2+ cluster of neurons in the far-rostral LPB, which we named the rostral-to-external lateral subnucleus (PBreL). These findings improve our understanding of LPB organization and reveal that Pdyn-IRES-Cre mice provide genetic access to warm-activated, FoxP2+ glutamatergic neurons in PBdL, many of which project to the hypothalamus.