Laboratorio de Neuroendocrinología Comparada, Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH), Provincia de Buenos Aires, Argentina.
J Comp Neurol. 2011 Dec 15;519(18):3748-65. doi: 10.1002/cne.22688.
Secretoneurin, a 33-34 amino acid neuropeptide derived from the proteolytic processing of the secretogranin-II precursor protein, is reasonably well conserved in evolution. Goldfish secretoneurin shares >75% similarity overall with other vertebrate secretoneurin sequences. The secretoneurin peptide has numerous functions that include neuroinflammation, neurotransmitter release, and neuroendocrine regulation. A detailed description of the central distribution of secretoneurin immunoreactivity is only known for the rat. Using our polyclonal antibody against the central, conserved core of the secretoneurin peptide we studied the distribution of secretoneurin-like immunoreactivity in the goldfish brain. Secretoneurin immunoreactivity was found in the olfactory bulb, entopeduncular nucleus, preoptic nucleus, lateral part of the lateral tuberal nucleus, posterior periventricular nucleus, nucleus of the posterior recess, the nucleus of the saccus vasculosus, and nucleus isthmi. Secretoneurin-immunoreactive fibers were found in the dorsal part of the dorsal telencephalon, ventral and lateral parts of the ventral telencephalon, periventricular preoptic nucleus, pituitary, and the ventrocaudal aspect of the nucleus of the lateral recess. The most conspicuous secretoneurin immunoreactivity was found in the magnocellular and parvocellular cells of the preoptic nucleus that project to the pituitary. Double-labeling studies indicated coexpression with isotocin, the fish homolog of mammalian oxytocin. Clear colabeling for secretoneurin and isotocin in fibers terminating in the neurointermediate lobe suggests that secretoneurin maybe coreleased with isotocin. Previous work indicates that secretoneurin stimulates the release of luteinizing hormone from the goldfish anterior pituitary. Our findings further support a reproductive role for secretoneurin and related peptides, given the importance of oxytocin family peptides in reproductive behavior in vertebrates.
脑啡肽，一种 33-34 个氨基酸的神经肽，来源于脑啡肽原 II 前体蛋白的蛋白水解加工，在进化中相当保守。金鱼脑啡肽与其他脊椎动物脑啡肽序列的总体相似性>75%。脑啡肽肽具有许多功能，包括神经炎症、神经递质释放和神经内分泌调节。只有大鼠的中枢脑啡肽免疫反应的详细分布情况是已知的。使用我们针对脑啡肽肽中心保守核心的多克隆抗体，我们研究了金鱼脑中脑啡肽样免疫反应的分布。在嗅球、缰核、视前核、外侧外侧管核、后室旁核、后室旁核、血管球囊核和峡核中发现了脑啡肽免疫反应。脑啡肽免疫反应纤维存在于背侧端脑的背侧部分、腹侧端脑的腹侧和外侧部分、室旁视前核、垂体和外侧憩室核的腹侧尾侧部分。最显著的脑啡肽免疫反应是在投射到垂体的视前核的大细胞和小细胞中发现的。双标记研究表明与同种型缩宫素（哺乳动物催产素的鱼类同源物）共表达。在终止于神经间脑的纤维中，脑啡肽和缩宫素的清晰共标记表明脑啡肽可能与缩宫素一起被释放。先前的工作表明脑啡肽刺激金鱼前垂体释放促黄体激素。我们的发现进一步支持了脑啡肽和相关肽的生殖作用，因为在脊椎动物中，催产素家族肽在生殖行为中具有重要性。
