Hypothalamic and brainstem sources of pituitary adenylate cyclase-activating polypeptide nerve fibers innervating the hypothalamic paraventricular nucleus in the rat
Hypothalamic and brainstem sources of pituitary adenylate cyclase-activating polypeptide nerve fibers innervating the hypothalamic paraventricular nucleus in the rat
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DOI：
10.1002/cne.21212
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发表时间：
2007-02-01
影响因子：
2.5
通讯作者：
Legradi, Gabor
中科院分区：
文献类型：
--
作者：
Das, Mahasweta;Vihlen, Christopher S.;Legradi, Gabor
下丘脑室旁核（PVN）协调主要的神经内分泌和行为机制，特别是对稳态挑战的反应。小细胞和大细胞PVN神经元受到垂体腺苷酸环化酶激活多肽（PACAP）轴突的丰富神经支配。我们最近的功能观察也表明，PACAP可能是在PVN水平的兴奋性神经肽。然而，投射到PVN的PACAP产生神经元的确切定位尚不清楚。本研究探讨了具体的贡献，不同的大脑区域发送PACAP神经支配的大鼠PVN通过使用离子电渗显微注射的逆行神经解剖示踪剂霍乱毒素B亚基（CT B）。通过使用CTh和PACAP的多重标记免疫荧光从下丘脑和脑干切片评价逆行转运。含有PACAP的细胞群被发现逆行标记的PVN在正中视前核;视前和外侧下丘脑区;弓状，背内侧，腹内侧，和乳头体上核;腹外侧中脑导水管周围灰质;嘴侧和中间水平腹外侧延髓，包括C1儿茶酚胺细胞群;孤束核;和迷走神经背侧运动核。小的PACAP投射与分散的双标记神经元起源于臂旁核，pericoeruleus区，和孤束核和延髓腹外侧区的尾侧区域。这些观察结果表明，PACAP神经支配PVN的多位点起源，并提供了一个强大的化学神经解剖学基础之间的相互作用PACAP和其潜在的靶神经元在PVN，如小细胞CRH神经元，控制生理反应的压力挑战和其他神经内分泌或前自主PVN神经元。
The hypothalamic paraventricular nucleus (PVN) coordinates major neuroendocrine and behavioral mechanisms, particularly responses to homeostatic challenges. Parvocellular and magnocellular PVN neurons are richly innervated by pituitary adenylate cyclase-activating polypeptide (PACAP) axons. Our recent functional observations have also suggested that PACAP may be an excitatory neuropeptide at the level of the PVN. Nevertheless, the exact localization of PACAP-producing neurons that project to the PVN is not understood. The present study examined the specific contribution of various brain areas sending PACAP innervation to the rat PVN by using iontophoretic microinjections of the retrograde neuroanatomical tracer cholera toxin B subunit (CTb). Retrograde transport was evaluated from hypothalamic and brainstem sections by using multiple labeling immunofluorescence for CTh and PACAP. PACAP-containing cell groups were found to be retrogradely labeled from the PVN in the median preoptic nucleus; preoptic and lateral hypothalamic areas; arcuate, dorsomedial, ventromedial, and supramammillary nuclei; ventrolateral midbrain periaqueductal gray; rostral and midlevel ventrolateral medulla, including the C1 catecholamine cell group; nucleus of the solitary tract; and dorsal motor nucleus of vagus. Minor PACAP projections with scattered double-labeled neurons originated from the parabrachial nucleus, pericoeruleus area, and caudal regions of the nucleus of the solitary tract and ventrolateral medulla. These observations indicate a multisite origin of PACAP innervation to the PVN and provide a strong chemical neuroanatomical foundation for interaction between PACAP and its potential target neurons in the PVN, such as parvocellular CRH neurons, controlling physiologic responses to stressful challenges and other neuroendocrine or preautonomic PVN neurons.