大壁虎与嗅觉相关的学习记忆

壁虎科动物鼻腔较大,化学感觉系统发达,类似于对化学信息敏感的舌端游离的蜥蜴目动物（Malan,1946),并且嗅黏膜面积很大,感觉器神经元多,嗅神经系统十分完善（Gabe and Saint,1976).     

Complete mitochondrial genome of the red-spotted tokay gecko (Gekko gecko, Reptilia: Gekkonidae): comparison of red- and black-spotted tokay geckos

Here, we sequenced the complete mitochondrial genome of the red-spotted tokay gecko (Squamata: Gekkonidae). The genome is 16,590 bp in size. Its gene arrangement pattern was identical with that of black-spotted tokay gecko. We compared the mitochondrial genome of red-spotted tokay gecko with that of the black-spotted tokay gecko. Nucleotide sequence of the two whole mitochondrial genomes was 97.99% similar, and the relatively high similarity seems to indicate that they may be separated at the subspecies level. The information of mitochondrial genome comparison of the two morphological types of tokay gecko is discussed in detail.     

Structure of the larynx of the tokay gecko (Gekko gecko), with particular reference to the vocal cords and glottal lips

The ability to vocalize is well-known in gekkonid lizards but relatively little attention has been paid to the structure of the vocal apparatus. In this study we briefly review the structure of the larynx and associated musculature of the tokay gecko as a baseline for a comparative survey of the family. The cricoid and arytenoid cartilages form the skeleton of the larynx and are controlled by constrictor and dilator muscles. The gross morphology of the vocal cords and glottal lips is then described, the structure being elucidated by way of dissection, histology, and scanning electron microscopy. The vocal cords run between the arytenoid and cricoid cartilages, are highly elastic, and bear a highly folded mucosa. The lips of the glottis have a structure reminiscent of erectile tissue. The respiratory mucosa of the larynx varies according to position and may be related to the tonal aspects of sound production. The structure of the larynx is compared with that of other vertebrates, and the relationship between morphology and phonation is considered.     

Interaction between thermal environments and hormones affecting skin-shedding frequency in the tokay (Gekko gecko) (Gekkonidae, Lacertilia)

Effects of thyroidectomy and/or hypophysectomy on the skin-shedding frequency (SF) in the tokay Gekko gecko and of thyroid hormones on the oxygen consumption (OCR) at various temperature regimes have been determined. Surgery invariably protracted the cycle length, thus decreasing SF; the extent of these changes was temperature dependent, the higher the temperature, the less the difference. Effects of hypophysectomy on cycle length were expressed in two phases; an extended first post-operative cycle was followed by a further extended second post-operative cycle, with cycle length forming a plateau thereafter. With time, the operated tokays would die without shedding during a greatly protracted cycle. OCRs in the tokay were temperature dependent, but between 28 and 34 degrees C, no significant difference could be seen. Effects of thyroid hormones on OCR were also temperature dependent. Furthermore, tokays having higher OCR were shown to have shorter cycles and vice versa. Results showed that whatever effect hormone(s) have on SF is indirect through general metabolic changes. SF is merely a reflection of the general metabolic status of the animal. It is proposed that the role of hormone(s), those of the thyroid in particular, is to act as "fine-tuning" devices in the regulation of metabolism and, as such, of the viability of the animal.     

Gas exchange morphometry of the lungs of the tokay,Gekko gecko L. (Reptilia: Squamata: Gekkonidae)

The tokay lizard (Gekko gecko) possesses singlechambered lungs, eacch of which is a mirror image of the other reflected in the midsagittal body plane. When standard techniques are employed for instilling 2% phosphate-buffered glutaraldehyde to three-quarters of the total lung capacity, neither the left nor the right lung is consistently larger. Internally, the lungs are characterized by a row of 11 dorsomedial niches and by honeycomb-like (faveolar) gas exchange tissue, which is deeper cranially than caudally. Based upon mean values for all experimental animals, a 100-g tokay would have an overall anatomical diffusion factor (respiratory surface area divided by the appropriate _ht) of 203 cm²·m^-1·100 g^-1, 61% of which is located on the interfaveolar septa. Of the total septal anatomical diffusion factor, 94% is evenly divided between the anterior and middle thirds of the lung, with 6% in the posterior third. The 39% of the anatomical diffusion factor located on the inner lung wall is predominantly (76%) in the middle and posterior lung thirds, with only 24% in the anterior region. These tendencies toward heterogeneous distribution of anatomical diffusion factor were most pronounced in a 55 g juvenile animal. In this animal the total anatomical diffusion faxtor/body mass was 3.6 times that of a 197 g adult. This difference was attributable to a greater body massspecific lung volume and respiratory surface area as well as to a greater surface-to-volume ratio in the parenchyma and to a thinner air-blood diffusion barrier in the juvenile animal.Abbreviations ADF anatomical diffusion factor - %AR percentage of potential respiratory surface area which makes up S_AR - DtO₂ diffusing capacity for air-blood tissue barrier - IUR isotropic uniform randomly distributed - bm body mass - %P percentage of lung volume devoted to parenchyma - S _A potential respiratory surface area (S _L minus the surface area of the trabeculae) - S _ANR non-respiratory surface area - S _AR respiratory surface area - S _L total internal surface area of the lung - S _v surface area-to-volume ratio in parenchyma - _ht harmonic mean thickness of the air-blood tissue barrier - V _L morphometrically determined volume of both lungs, fixed at 0.75· V _Lm - V _Lm maximal lung volume, similar to total lung capacity in mammals - V _Lr resting lung volume, similar to functional residual capacity in mammals - VP morphometrically determined volume of parenchyma of both lungs, fixed at three-quarters of V_Lm     

The effects of androgens on the β-glands of the tokay (Gekko gecko): Modification of an hypothesis

Study of the posterior abdominal epidermis in hypophysectomized/thyroidectomized male and female tokays following surgery, and subsequent androgen therapy, indicates that, contrary to a previous model, all aspects of β-gland differentiation are under direct androgenic control. On the other hand, another epidermal specialization, the digital foot-pad, shows a pattern of histogenesis directly comparable to that of β-glands, but is unaffected by androgens. These data are discussed with respect to the evolution of glandular epidermal specializations in gekkonid lizards and the possible role of androgens in modifying the control of cell differentiation in lizard epidermis.     

Mesotocin and vasotocin in the brain of the lizard Gekko gecko

Summary The distribution of mesotocin and vasotocin was studied in the brain of the lizard Gekko gecko with antisera specific for either peptide. Both mesotocinergic and vasotocinergic perikarya are found in the paraventricular and supraoptic nuclei of the hypothalamus, whereas vasotocinergic neurons are exclusively present in the bed nucleus of the stria terminalis and in a cell group of the rhombencephalon. The distributional pattern of the mesotocinergic fibers corresponds closely to that of the vasotocinergic fibers. However, throughout the entire brain the mesotocinergic innervation is less dense than the vasotocinergic innervation. No sex differences are present in the mesotocinergic fiber system.Abbreviations acc nucleus accumbens - bst bed nucleus of the stria terminalis - bv blood vessel - dB diagonal band of Broca - dc dorsal cortex - dth dorsolateral thalamic nucleus - lc lateral cortex - me median eminence - oc optic chiasma - ot optic tract - pag periaqueductal grey - pvn paraventricular nucleus - rc rhombencephalic cell group - sep septum - son supraoptic nucleus - tect mesencephalic tectum - vth ventrolateral thalamus     

广西弄岗国家级自然保护区蛤蚧分布与种群数量

2008年5～6月,采用访问调查和样线法,对弄岗国家级自然保护区蛤蚧Gekko gecko的分布和种群数量进行了调查.结果表明,弄岗片蛤蚧分布较多,陇山片和陇呼片分布较少;用样线法重点对弄岗片蛤蚧数量进行调查,根据统计数据计算出种群密度为13.45对/km2.     

Viscoelastic features of adhesive setae of the tokay gecko (<Emphasis Type="Italic">Gekko gecko</Emphasis> L.)

Deformations of particular setae of adhesive toe pad of the tokay gecko were investigated by atomic-force microscopy. The effective elastic modulus of the investigated setae varying within 0.34–19 GPa, a pronounced hysteresis was observed during reversible bending of setae. The hysteresis-related energy losses may be as high as 98% of the total bending work. The pronounced viscous features of the setae contradict the hypothesis of dynamic self-cleaning of the gecko adhesive cover, according to which the setae are considered as absolutely elastic cantilever beams.     

A scanning electron microscope study of the papilla basilaris of Gekko gecko

Summary The sensory hair cells of the ventral 2/3 of the papilla basilaris of Gekko gecko are divided into anterior (pre-axial) and posterior (post-axial) portions by a mid-axial gap or hiatus where there are no hair cells. There is no separation of the hair cells in the dorsal third of the papilla. There are three tectorial membrane modifications: an attached thickened membrane covering the pre-axial hair cells, sallets covering the post-axial hair cells, and an attached filamentous membrane covering the dorsal hair cells. The number of hair cells is greatest ventrally and decreases dorsally. There are approximately 2000 to 2100 hair cells. The kinocilia of the hair cells of the anterior halves of both the pre- and the post-axial vertical hair-cell rows are oriented posteriorly, while the kinocilia of the posterior halves are oriented anteriorly. The kinocilia of the hair cells of the dorsal third of the papilla are mostly oriented posteriorly. Thus, kinocilial orientation of the ventral 2/3 of the papilla is doubly bidirectional, and the dorsal 1/3, largely unidirectional.I would like to thank Ms. Maria Maglio for her skill in handling the technical aspects of the scanning electron microscopy as well as her artistry in achieving photographic excellence on the scope, David Akers for expert photographic assistance, and Wayne Emery for the drawings. Research sponsored by United States Public Health Service Grant NS-09231.     

蛤蚧与中国石龙子顶盖组织结构的比较

通过对蛤蚧与中国石龙子顶盖细胞形态及细胞在顶盖不同层次间的比较,研究两种不同习性动物视觉结构之间的差异.用尼氏(Nissl)染色法进行顶盖组织染色,辣根过氧化物酶(horseradish peroxidase,HRP)进行顶盖注射,测量和记录顶盖细胞的面积、形态及树突走向并作统计分析.结果显示两种动物顶盖层次间的投射方式及细胞在各层次的比较存在相似之处,而中国石龙子顶盖C层细胞面积显著大于蛤蚧,其S层细胞树突分枝比蛤蚧的要广泛,而且这两种动物不同大小和不同形态顶盖细胞所占比例在顶盖内部三层间也存在差别.这些结果表明夜行性蛤蚧和昼行性中国石龙子的视觉系统中,其顶盖结构存在差异.     

蜣螂与壁虎刚毛的比较及改形对其功能的影响

脱附与粘附是工程作业的两个相互矛盾的难题,土壤和物料的粘附严重降低了机械的作业效率和质量,没有粘附又使某些机械无法工作或运行。目前世界流行的脱附技术,包括向界面注入空气的充气法、向界面注入溶液的充液法、利用机械或超声波的振动法、施加电场的电渗法、施加磁场的磁     

蛤蚧视觉神经核团的细胞形态结构及功能的研究

本研究发现,蛤蚧视觉神经核团有视顶盖（OT）、峡核（NI）、基底视束核（nBOR）、豆状核（LM）、中脑深部核（NPM）、圆核（NR）、前背侧室嵴（ADVR）和皮质加厚区（Pth）等,其中NI和ADVR两核团的体积最大。视觉核团中有各种形状的细胞形态,其中梨形和梭形细胞占的比例较大。神经核团的细胞直径为6～30μm,其中以15～28μm最多。在ADVR和Pth核团中有细胞丛簇存在,其它核团尚未发现有这样的结构。各神经核团问和核团内有广泛而复杂的纤维联系。蛤蚧有关视觉神经核团除具有视觉功能外,可能还与听觉、触觉、嗅觉和平衡感觉等功能有关。     

Molecular evolution of the cone visual pigments in the pure rod-retina of the nocturnal gecko, Gekko gekko

We have isolated a full-length cDNA encoding a putative ultraviolet (UV)-sensitive visual pigment of the Tokay gecko (Gekko gekko). This clone has 57 and 59% sequence similarities to the gecko RH2 and MWS pigment genes, respectively, but it shows 87% similarity to the UV pigment gene of the American chameleon (Anolis carolinensis). The evolutionary rates of amino acid replacement are significantly higher in the three gecko pigments than in the corresponding chameleon pigments. The accelerated evolutionary rates reflect not only the transition from cones to rods in the retina but also the blue-shift in the absorption spectra of the gecko pigments.     

Review: mapping proteins localized in adhesive setae of the tokay gecko and their possible influence on the mechanism of adhesion

The digital adhesive pads that allow gecko lizards to climb vertical surfaces result from the modification of the oberhautchen layer of the epidermis in normal scales. This produces sticky filaments of 10–100 μm in length, called setae that are composed of various proteins. The prevalent types, termed corneous beta proteins (CBPs), have a low molecular weight (12–20 kDa) and contain a conserved central region of 34 amino acids with a beta-conformation. This determines their polymerization into long beta-filaments that aggregate into corneous beta-bundles that form the framework of setae. Previous studies showed that the prevalent CBPs in the setae of Gekko gecko are cysteine-rich and are distributed from the base to the tip of adhesive setae, called spatulae. The molecular analysis of these proteins, although the three-dimensional structure remains undetermined, indicates that most of them are charged positively and some contain aromatic amino acids. These characteristics may impede adhesion by causing the setae to stick together but may also potentiate the van der Waals interactions responsible for most of the adhesion process on hydrophobic or hydrophilic substrates. The review stresses that not only the nanostructural shape and the high number of setae present in adhesive pads but also the protein composition of setae influence the strength of adhesion to almost any type of substrate. Therefore, formulation of dry materials mimicking gecko adhesiveness should also consider the chemical nature of the polymers utilized to fabricate the future dry adhesives in order to obtain the highest performance.     

蛤蚧前背侧室嵴(ADVR)的分区及细胞形态学研究

采用解剖学方法和绀织学方法仔细观察,分析蛤蚧（Gekko gecko）前背侧室嵴（ADVR）的形态学分区,发现以ADVR表面的浅沟为标记,参照细胞着色深浅,细胞密度分布特征以及细胞形态大小,可将ADVR分为内侧区（ma）、嘴外侧区（rla）和尾外侧区（cla）等3个部分,为ADVR的结构功能的深入研究提供了形态学依据。     

Mitochondrial Diversity and Phylogeographic Patterns of Gekko gecko(Squamata: Gekkonidae) in Thailand

The Tokay Gecko, Gekko gecko(Linnaeus, 1758) is widely distributed in Asia and there have been concerns regarding locally decreasing populations due to overexploitation for traditional Chinese medicine. Previous studies of the genetic relationships of G. gecko populations included few populations from Thailand. Here we investigated the phylogeographic patterns of G. gecko from different regions in Thailand using mitochondrial cytochrome b sequences. Phylogenetic analyses revealed two lineages: one(Lineage A) comprising populations from Laos, Vietnam, and Thailand; and a second(Lineage B) comprising three genetically distinct groups within Thailand alone. Some Thai populations were found to have both lineages represented within them. Highly significant genetic differentiation(FST) showed geographic population structuring in Lineage B, indicating limited gene flow among groups in Thailand. Although G. gecko has a wide distribution and is well adapted to human habitation, the observed genetic structure could potentially be explained by geographic barriers such as mountain ranges. In Lineage A, our study provided primary phylogeographic evidence for lineage mixture that might be a result of human-mediated transport. Future research should include more extensive sampling across the geographic distribution of G. gecko and a landscape genetics approach could be applied for conservation planning.     

电刺激大壁虎中脑诱发相反方向脊柱侧弯的研究

深入探索大壁虎Gekko gecko中脑运动调控功能,通过对头部固定的大壁虎(n=10)中脑脑区采用不锈钢微电极施加电刺激,发现对中脑不同深度脑区的电刺激能诱发出脊柱侧弯、四肢动等运动反应.在实验过程中,一些刺激针道在中脑围脑室灰质诱发出脊柱同侧弯曲反应,而在中脑腹侧被盖诱发出脊柱对侧弯曲反应.通过对刺激脑区的组织学检验,确定了大壁虎中脑内控制相反方向脊柱侧弯运动核团分布的大致区域.