Cocaine- and amphetamine-regulated transcript in catecholamine and noncatecholamine presympathetic vasomotor neurons of rat rostral ventrolateral medulla
Cocaine- and amphetamine-regulated transcript in catecholamine and noncatecholamine presympathetic vasomotor neurons of rat rostral ventrolateral medulla
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DOI：
10.1002/cne.20198
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发表时间：
2004-08-09
影响因子：
2.5
通讯作者：
Llewellyn-Smith, IJ
中科院分区：
文献类型：
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作者：
Burman, KJ;Sartor, DM;Llewellyn-Smith, IJ
延髓头端腹外侧区(RVLM)的交感神经前血管运动性肾上腺素能神经元(C_1)和非C_1能神经元(N_1)是脊髓心血管交感节前神经元的主要兴奋性动力。C_1和非C_1神经元均含有可卡因和苯丙胺调节转录本(CART)，提示CART可能是RVLM前交感神经元的共同标志物。为了验证这一假设，我们首先使用CART和酪氨酸羟化酶(TH)的双重免疫荧光染色来定量Cart免疫反应(-IR)的儿茶酚胺和非儿茶酚胺神经元。接下来，我们用过氧化物酶免疫组织化学方法对Fos进行定量，并对CART和TH进行双重免疫荧光，以量化CART-IR RVLM神经元在低血压刺激下表达Fos的比例。最后，我们在电生理鉴定的、细胞旁标记的RVLM前交感神经元中荧光检测CART免疫反应。在RVLM，97%的TH-IR神经元为CART-IR，74%的CART-IR神经元为TH-IR。与生理盐水对照组相比，硝普钠灌流可显著增加Fos-IR RVLM神经元的数量。在硝普钠处理的大鼠，RVLM内几乎所有的Fos/TH神经元都表达CART(98%+/-1.3%，SD；n=7)，而29%+/-8.3%的CART阳性、TH阴性的神经元显示Fos免疫反应。6个快速(2.8-5.8米/秒，非儿茶酚胺)-，2个中速(2.1和2.2米/秒)-，5个慢速(
Presympathetic vasomotor adrenergic (C1) and nonadrenergic (non-C1) neurons in the rostral ventrolateral medulla (RVLM) provide the main excitatory drive to cardiovascular sympathetic preganglionic neurons in the spinal cord. C1 and non-Cl neurons contain cocaine- and amphetamine-regulated transcript (CART), suggesting that CART may he a common marker for RVLM presympathetic neurons. To test this hypothesis, we first used double-immunofluorescence staining for CART and tyrosine hydroxylase (TH) to quantify CART-immunoreactive (-IR) catecholamine and noncatecholamine neurons in the C1 region. Next, we quantified the proportion of CART-IR RVLM neurons that expressed Fos in response to a hypotensive stimulus, using peroxidase immunohistochemistry for Fos and dual immunofluorescence for CART and TH. Finally, we fluorescently detected CART immunoreactivity in electro-physiologically identified, juxtacellularly labeled RVLM presympathetic neurons. In the RVLM, 97% of TH-IR neurons were CART-IR, and 74% of CART-IR neurons were TH-IR. Nitroprusside infusion significantly increased the number of Fos-IR RVLM neurons compared with saline controls. In nitroprusside-treated rats, virtually all Fos/TH neurons in the RVLM were immunoreactive for CART (98% +/- 1.3%, SD; n = 7), whereas 29% +/- 8.3% of CART-positive, TH-negative neurons showed Fos immunoreactivity. Six fast (2.8-5.8 m/second, noneatecholamine)-, two intermediate (2.1 and 2.2 m/second)-, and five slow (