Vallarino M, Tranchand-Bunel D, Thoumas J L, Masini M A, Conlon J M, Fournier A, Pelletier G, Vaudry H
Istituto di Anatomia Comparata, Università di Genova, Italy.
J Comp Neurol. 1995 Jun 12;356(4):537-51. doi: 10.1002/cne.903560405.
Lungfishes, which share similarities with both fishes and amphibians, represent an interesting group in which to investigate the evolutionary transition from fishes to tetrapods. In the present study, we have investigated the localization and biochemical characteristics of neuropeptide Y (NPY)-immunoreactive material in the central nervous system of the African lungfish, Protopterus annectens. NPY-immunoreactive cell bodies were found in various regions of the brain, most notably in the telencephalon (septal area, ventral striatum, and nucleus accumbens), in the diencephalon (preoptic nucleus, periventricular region of the hypothalamus, and ventral thalamus), and in the tegmentum of the mesencephalon. A strong immunoreaction was also detected in cell bodies of the nervus terminalis. Immunoreactive nerve fibers were particularly abundant in the ventral striatum, the nucleus accumbens, the diagonal band of Broca, the hypothalamus, and the mesencephalic tegmentum. Positive fibers were also seen in the median eminence and in the neural lobe of the pituitary. The NPY-immunoreactive material localized in the brain and pituitary was characterized by combining high-performance liquid chromatography (HPLC) analysis and radioimmunological quantitation. The displacement curves obtained with synthetic porcine and frog NPY and serial dilutions of brain and pituitary extracts were parallel. Reversed-phase HPLC analysis of telencephalon, diencephalon, and pituitary extracts resolved a major NPY-immunoreactive peak that coeluted with frog NPY. The similarity between the distribution of NPY-containing neurons and the biochemical characteristics of the immunoreactive peptide in the brain of lungfish and frog strongly favors a close phylogenetic relationship between dipnoans and amphibians.
肺鱼与鱼类和两栖动物都有相似之处，是研究从鱼类到四足动物进化过渡的一个有趣的类群。在本研究中，我们调查了非洲肺鱼（Protopterus annectens）中枢神经系统中神经肽Y（NPY）免疫反应性物质的定位和生化特性。在大脑的各个区域发现了NPY免疫反应性细胞体，最显著的是在端脑（隔区、腹侧纹状体和伏隔核）、间脑（视前核、下丘脑室周区和腹侧丘脑）以及中脑被盖。在终神经的细胞体中也检测到强烈的免疫反应。免疫反应性神经纤维在腹侧纹状体、伏隔核、布洛卡斜带、下丘脑和中脑被盖中特别丰富。在正中隆起和垂体神经叶中也可见到阳性纤维。通过高效液相色谱（HPLC）分析和放射免疫定量相结合的方法，对大脑和垂体中定位的NPY免疫反应性物质进行了表征。用合成猪和青蛙NPY以及大脑和垂体提取物的系列稀释液获得的置换曲线是平行的。对端脑、间脑和垂体提取物的反相HPLC分析分离出一个主要的NPY免疫反应性峰，该峰与青蛙NPY共洗脱。肺鱼和青蛙大脑中含NPY神经元的分布与免疫反应性肽的生化特性之间的相似性强烈支持了肺鱼和两栖动物之间密切的系统发育关系。
