Injections of the of the α1-adrenoceptor antagonist prazosin into the median raphe nucleus increase food intake and Fos expression in orexin neurons of free-feeding rats
Injections of the of the α1-adrenoceptor antagonist prazosin into the median raphe nucleus increase food intake and Fos expression in orexin neurons of free-feeding rats
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DOI：
10.1016/j.bbr.2017.02.021
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发表时间：
2017-05-01
影响因子：
2.7
通讯作者：
Paschoalini, Marta Aparecida
中科院分区：
文献类型：
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作者：
da Silva, Eduardo Simao;Flores, Rafael Appel;Paschoalini, Marta Aparecida
在此之前，我们发现，在中缝正中核（MnR）的α 1-肾上腺素受体的封锁增加了自由进食大鼠的食物摄入量，表明肾上腺素能机制的MnR参与调节食物摄入量。然而，这种药理学操作对与食物摄入相关的其他神经回路的影响仍然未知。在目前的研究中，我们试图确定前脑区域的α 1-肾上腺素能受体阻滞剂的反应，并推测参与调制的摄食反应。为了这个目的，我们研究了c-Fos免疫反应性的诱导前脑结构注射α 1-肾上腺素受体拮抗剂哌唑嗪到自由喂养大鼠的MnR。为了确定下丘脑c-Fos阳性细胞的化学身份，我们进行了Fos/食欲素（OX）或Fos/黑色素浓集激素（MCH）的双标记免疫组织化学。最后，我们结合顺行追踪从MnR与免疫组化检测食欲素。哌唑嗪注射到MnR显着增加食物摄入量。摄食反应伴随着基底外侧杏仁核（BLA）和下丘脑外侧区（LHA）Fos表达的增加。在LHA中，Fos表达发生在表达OX的神经元中，但不表达MCH。结合顺行追踪实验表明，LHA OX神经元显着的MnR轴突的目标。这些研究结果表明，内MnR注射哌唑嗪，通过激活食欲素能神经元的LHA和非食欲素能神经元的BLA，诱发了对食物摄入的动机反应。(C)2017爱思唯尔B. V.保留所有权利。
Previously, we showed that the blockade of alpha 1-adrenoreceptors in the median raphe nucleus (MnR) increased food intake in free-feeding rats, indicating that adrenergic mechanisms in the MnR participate in the regulation of food intake. However, the impact of such a pharmacological manipulation on other neural circuits related to food intake remains unknown. In the current study, we sought to identify forebrain regions which are responsive to alpha 1-adrenergic receptor blockade and presumably involved in the modulation of the feeding response. For this purpose, we examined the induction of c-Fos immunoreactivity in forebrain structures following injections of the alpha 1-adrenoceptor antagonist prazosin into the MnR of free-feeding rats. To determine the chemical identity of hypothalamic c-Fos-positive cells, we then conducted double-label immunohistochemistry for Fos/orexin (OX) or Fos/melanin-concentrating hormone (MCH). Finally, we combined anterograde tracing from the MnR with immunohistochemical detection of orexin. Prazosin injections into the MnR significantly increased food intake. The ingestive response was accompanied by an increase in Fos expression in the basolateral amygdala (BLA) and lateral hypothalamic area (LHA). In the LHA, Fos expression occurred in neurons expressing OX, but not MCH. Combined anterograde tracing experiments revealed that LHA OX neurons are prominently targeted by MnR axons. These findings suggest that intra-MnR injection of prazosin, via activation of orexinergic neurons in the LHA and non-orexinergic neurons in the BLA, evoked a motivational response toward food intake. (C) 2017 Elsevier B.V. All rights reserved.