【作者】 王智超；

【导师】 鲁亚平；

【作者基本信息】 安徽师范大学 ， 动物学， 2006， 硕士

【摘要】 生物的许多生化、生理和行为指标都呈现昼夜性的波动,这种接近24小时周期变化的生物节律称为昼夜节律。生物体的昼夜节律性受昼夜节律钟(circadian clock)控制。以往的观点认为爬行动物昼夜节律钟最重要的中枢是松果体及视网膜,所以研究者主要把精力放在松果体和视网膜上。近年的研究表明,同时损伤侧眼(视网膜)、松果体(腺)后,多数蜥蜴类爬行动物的生理功能及行为等仍具有明显昼夜节律性(Innocenti,1993;Berk and Heath,1975;Tosini and Menaker,1998),而损伤下丘脑的某些核团可以完全破坏某些爬行动物的昼夜节律,因此多数学者认为下丘脑可能也是爬行动物昼夜节律钟重要的震荡器。垂体后叶激素是一类广泛存在于脊椎动物各等级类群的古老激素,在哺乳动物中目前认为精氨酸加压素(arginine vasopressin ,AVP)为生物钟的重要而稳定的输出信号和整合信号(Hofman,2003; Dunlap,1999; Hastings et al,2003; Maria,2003),在不同光周期下其在视交叉上核均呈现特征性的昼夜节律性表达。那么精氨酸加压催产素(arginine vasotocin,AVT)作为精氨酸加压素在爬行动物的同源物,其在无蹼壁虎(Gekko swinhonis)下丘脑是否表达?其表达是否呈现昼夜节律性?不同的光周期及不同温度下其表达是否有变化呢?运用免疫组织化学和数学形态学方法,我们发现在无蹼壁虎全脑AVP免疫阳性细胞主要分布在鲁卡斜角带核、视上核、室旁核,在室周视前区、终纹床核,下丘脑外侧区、前脑外侧束、室周核出现零散的几个细胞;阳性细胞形态多样,呈圆形、梨形、或双极形,但多以圆形为主,免疫染色主要位于细胞质和细胞突起,细胞核不着色或浅着色。而AVP免疫阳性纤维除了在嗅球、嗅束、大脑皮层、视叶、小脑皮层未见外,几乎贯穿全脑其他部位。在进行全脑AVP免疫阳性细胞定位和纤维投射观察的基础上,我们选取了在所有报道的爬行动物均有AVT表达的两个核团(视上核与室旁核)进行更多还原

【Abstract】 Many biochemical, physiological, and behavioral parameters exhibited by organisms show daily fluctuations, and most of these fluctuations persist when the organisms are maintained in constant environmental conditions, thus demonstrating that they are driven by an endogenous oscillator. Rhythms that persist in constant conditions with a period close to 24-h are called circadian. In reptiles and other nonmammalian vertebrates the importance usually ascribed to the pineal gland and the eyes in the circadian organization and sustainment. But during the last decade the suprachiasmatic nucleus(SCN) have also been recognized to play a role in the circadian system of lizards and the SCN of lizards are topographically similar to the SCN of rodents. Furthermore, the fact that some circadian rhythm of behavior is not definitely abolished after both parietalectomy and pinealectomy suggested that the SCN or neighboring hypothalamic areas may also be involved in driving this rhythm. Arginine vasopressin belonging to Neurohypophyseal hormones which occurs within the various classes of vertebrates and nonvertebrates, is an ancient hormone of animal. AVP, that is expressed with a circadian rhythm in DD is considered as an important candidate for output signal and modulator of the SCN of mammalians. Arginine-vasotocin(AVT) is known to be the homologous form of AVP in reptiles, then what is the role of AVT in reptilian circadian rhythms?The present investigation was carried out in our model animal Gekko swinhonis, and was aimed at testing whether AVT be used as marker(s) of circadian oscillation of the lizard . For this purpose, by using immunohistochemistry and morphometry we examined the distribution of AVT in the brain and the circadian changes of AVT expression in the hypothalamus of更多还原