| collagen type conservation during metamorphic repatterning of the dermal fibers in salamanders. | the orientation of the fibers in the dermis of the tiger salamander, ambystoma tigrinum, undergoes a dramatic repatterning at metamorphosis. the pre-metamorphic, larval dermis is a tight layer composed of crossed fibers that wind helically around the trunk. this condition is retained by neotenic adults which do not undergo metamorphosis. in contrast, the neotenic adults which do not undergo metamorphosis. in contrast, the metamorphosed adult dermis consists of a superficial, loose network of fib ... | 1991 | 1890686 |
| blockage and permeation of divalent cations through the cyclic gmp-activated channel from tiger salamander retinal rods. | 1. blockage and permeation of divalent cations through channels activated by guanosine 3',5'-cyclic monophosphate (cyclic gmp) were studied in membrane patches excised from retinal rods of the tiger salamander ambystoma tigrinum by rapidly changing the ionic medium bathing the intracellular side of the excised membrane. 2. the na+ current, observed when 110 mm-nacl was present on both sides of the membrane patch, was reduced by the addition of 1 mm of the chloride salts of ca2+, mg2+, sr2+, ba2+ ... | 1991 | 1725182 |
| voltage-dependent ionic currents in taste receptor cells of the larval tiger salamander. | voltage-dependent membrane currents of cells dissociated from tongues of larval tiger salamanders (ambystoma tigrinum) were studied using whole-cell and single-channel patch-clamp techniques. nongustatory epithelial cells displayed only passive membrane properties. cells dissociated from taste buds, presumed to be gustatory receptor cells, generated both inward and outward currents in response to depolarizing voltage steps from a holding potential of -60 or -80 mv. almost all taste cells display ... | 1990 | 1701829 |
| spatial organization of the bipolar cell's receptive field in the retina of the tiger salamander. | 1. the spatial properties of rods, horizontal cells and bipolar cells were studied by intracellular recording in the isolated, perfused retina of the tiger salamander, ambystoma tigrinum. low stimulus intensities were used in order to keep cell responses close to, or within, their linear intensity/response range. 2. spatial properties of bipolar cell receptive fields, measured while perfusing with normal ringer solution, were compared with those measured during exposure to agents that eliminated ... | 1990 | 2348392 |
| transduction noise induced by 4-hydroxy retinals in rod photoreceptors. | new visual pigments were formed with 4-hydroxy retinals in isolated vertebrate rod photoreceptors by exposing bleached rods from the tiger salamander, ambystoma tigrinum, to lipid vesicles containing the analogues. formation of physiologically active pigment was demonstrated by the restoration of sensitivity and by a shift of approximately 50 nm in the peak of both the visual pigment absorptance spectrum and rod spectral sensitivity spectrum from approximately 520 to approximately 470 nm for 11- ... | 1990 | 2297557 |
| depolarization-induced alkalinization in proximal tubules. ii. effects of lactate and sits. | intracellular ph and voltage microelectrodes were used to further characterize the depolarization-induced alkalinization (dia) observed in isolated perfused proximal tubules of the tiger salamander ambystoma tigrinum. tubules were depolarized by raising basolateral [k+] from 2.5 to 50 mm. the solutions were air equilibrated and nominally hco3- free (estimated [hco3-] = 0.2 mm). in the preceding study we showed that the dia is partially blocked by removal of na+ from only the lumen or only the ba ... | 1989 | 2916667 |
| depolarization-induced alkalinization in proximal tubules. i. characteristics and dependence on na+. | we used intracellular ph-sensitive and voltage microelectrodes to examine the effects of depolarization on intracellular ph (phi) in isolated perfused proximal tubules from the tiger salamander ambystoma tigrinum. tubules were depolarized by raising [k+] in the bath (b) or lumen (l), or by adding ba2+ (1 mm) to the bath or lumen, always in nominally hco3-free solutions. increasing [k+]b from 2.5 to 50 mm caused the basolateral membrane to depolarize by an average of 45 mv, and phi to increase by ... | 1989 | 2916666 |
| a comparison of the discriminatory ability and sensitivity of the trigeminal and olfactory systems to chemical stimuli in the tiger salamander. | trigeminal receptors can respond to a wide variety of chemical stimuli, but it is unknown whether these receptors mediate discrimination between chemical stimuli matched for equal perceptual intensity. the present electrophysiological and behavioral experiments address this issue using tiger salamanders, ambystoma tigrinum, and four compounds (amyl acetate, cyclohexanone, butanol, and d-limonene). in addition, the relative sensitivities of the trigeminal and olfactory systems to these compounds ... | 1988 | 3236261 |
| blood flow patterns in the salamander, ambystoma tigrinum, before, during and after metamorphosis. | the patterns of blood flow through the complex circulation of the tiger salamander, ambystoma tigrinum, were investigated during aquatic normoxia and hypoxia by application of the microsphere technique. the distribution of differently labelled microspheres injected into the bloodstream towards the left and right atria, respectively, was used to evaluate the role of the ductus arteriosus in lung perfusion before, during and after metamorphosis, as well as the general contribution of right and lef ... | 1988 | 3209973 |
| electrical coupling between rods and cones in the tiger salamander retina. | electrical coupling between rods and cones was studied in the salamander (ambystoma tigrinum) retina by measuring the light responses and spectral sensitivities of rods and cones and by measuring the voltage responses from a rod to current pulses injected into a cone. a population of 10-20% of the photoreceptors exhibited a mixed-response waveform of the rod and the cone under dark-adapted conditions, and a response waveform closely resembled that of a cone in the presence of background illumina ... | 1988 | 3422423 |
| allometry of red cell oxygen binding and hematology in larvae of the salamander, ambystoma tigrinum. | very few studies have attempted to relate blood characteristics to body mass within, rather than between, species. thus, respiratory and hematological properties of the blood of larval tiger salamanders (ambystoma tigrinum) have been measured in animals ranging in body mass from approximately 2 to 112 g. this amphibian species was chosen because larvae of very different body mass may be of similar developmental stage, minimizing interference from ontogenetic factors. mean corpuscular volume, mea ... | 1987 | 3659611 |
| voltage gain of signal transfer from retinal rods to bipolar cells in the tiger salamander. | 1. intracellular recordings of the voltage responses of rods and both functional classes of bipolar cell were made in the isolated, perfused retina of the tiger salamander, ambystoma tigrinum. 2. brief, dim flashes of 519 nm light delivered to the receptive-field centres were used to measure the flash sensitivities of twenty-one on-centre bipolar cells and thirty-six off-centre cells. in each experiment the flash sensitivity of a rod was also measured using diffuse illumination of the same durat ... | 1987 | 3443944 |
| generalization in olfactory detection of chemical cues containing carbonyl functions by tiger salamanders (ambystoma tigrinum). | tiger salamanders generalize behaviorally between carbonyl-containing odorants (e.g., aldehydes or cycloalkanones). however, responding does not generalize from such odorants to stimulus compounds with comparable molecular shapes and dimensions but different functional groups. discrimination between aldehydes and a ketone is temporarily impaired by two-step covalent modification of the olfactory epithelium. two-step modification of the olfactory epithelia also impairs, but does not obliterate, o ... | 1987 | 24301355 |
| effect of microhabitat on fitness components of larval tiger salamanders, ambystoma tigrinum nebulosum. | survivorship and growth of larval tiger salamanders, ambystoma tigrinum nebulosum, in the white mountains of east-central arizona were compared in six microhabitats using field enclosures during summers, 1983-85. microhabitats were vegetated and nonvegetated shallows, surface, middle, and bottom horizontal layers of limnetic areas, and the vertical limnetic water column. initial enclosure densities (0.025 larvae per 1) were identical among microhabitats. three enclosures were placed in each micr ... | 1986 | 28312097 |
| photoreceptors of the larval tiger salamander retina. | six morphological types of photoreceptor were identified with electron microscopy in radial sections of the retina of the larval tiger salamander, ambystoma tigrinum. in order of predominance these six types are: red rods, large single cones, double cones composed of principal and accessory members, small single cones, and green rods. the different types of photoreceptor can be distinguished by a number of morphological and cytological characteristics. the identification of the small single cone ... | 1986 | 2873578 |
| olfactory responses of aquatic and terrestrial tiger salamanders to airborne and waterborne stimuli. | electro-olfactograms (eogs) were used to assess olfactory responding by aquatic larval and terrestrial adult tiger salamanders (ambystoma tigrinum) to airborne volatile compounds, and volatile and non-volatile compounds in aqueous solution. both forms of salamander showed saturation effects to presentations of airborne stimuli (fig. 2). saturation was not observed, however, to stimulus presentations in aqueous solution (figs. 2, 3). when threshold values and concentration-response curve paramete ... | 1986 | 3723439 |
| antagonistic effects of prolactin and oxytocin on tail fin regression and acid phosphatase activity in metamorphosing ambystoma tigrinum. | we have found that the inhibition of thyroxine-induced tail fin regression by prolactin in larval tiger salamanders is antagonized by oxytocin. other workers have shown that prolactin blocks the rise in activity of several hydrolytic enzymes that occurs in regressing tissue during metamorphosis. here, we examine the effects of prolactin and oxytocin--given alone and in combination--on tail fin regression and acid phosphatase specific activity in this tissue. both long-term (12-day) and short-ter ... | 1986 | 3956990 |
| electrical properties of the light-sensitive conductance of rods of the salamander ambystoma tigrinum. | the light-sensitive conductance of isolated rods from the retina of the tiger salamander was studied using a voltage-clamp method. the membrane current of the outer segment was collected with a suction electrode while the internal voltage was measured and controlled with a pair of intracellular electrodes. saturating light blocked the outer segment current at all potentials, the residual conductance usually becoming less than 20 ps. this suggests that light-sensitive channels comprise the main i ... | 1986 | 2422346 |
| banding differences between tiger salamander and axolotl chromosomes. | the hoechst 33258 - giemsa banding patterns were compared on axolotl (ambystoma mexicanum shaw) and axolotl - tiger salamander (ambystoma tigrinum green) species hybrid prophase chromosomes. approximately 369 bands per haploid chromosome set were seen in the axolotl and about 344 bands in the tiger salamander. in the haploid set of 14 chromosomes, chromosome 3 has a constant short or q-arm terminal constriction at the location of the nucleolar organizer. chromosomes 14 z and w carry the sex dete ... | 1985 | 4063874 |
| cyclic gmp increases photocurrent and light sensitivity of retinal cones. | like retinal rods, cone photoreceptors contain cyclic gmp and light-activated phosphodiesterase. the cgmp phosphodiesterase cascade is thought to mediate phototransduction in rods. biochemical assays of nucleotide content in cone-dominant retinas, however, have failed to demonstrate light-induced changes in cgmp. changes in cyclic amp following light exposure have been reported, leading to the suggestion that in cone phototransduction camp assumes a role analogous to that played by cgmp in rods. ... | 2016 | 2993915 |
| a practical method for staging metamorphosis in the tiger salamander ambystoma tigrinum. | the aim of this study was to develop a set of practical metamorphic stages for the tiger salamander ambystoma tigrinum that would 1) provide an early and quantifiable marker of the onset of metamorphosis and 2) not be dependent on knowledge of maximal values of gill length or tail height. twenty morphological parameters were obtained from ambystoma tigrinum larvae as they progressed through laboratory-induced metamorphosis (21 degrees c, continuous light). these parameters included measures of b ... | 1985 | 3985374 |
| adrenoceptor types in the respiratory vasculature of the salamander gill. | adrenoreceptor types were determined in the branchial respiratory vasculature of the neotenic tiger salamander, ambystoma tigrinum. phenoxybenzamine antagonized increases in branchial vascular resistance caused by both epinephrine and norepinephrine. propranolol antagonized both epinephrine- and norepinephrine-induced dilation of this vascular bed. isoproterenol produced solely vasodilation, phenylephrine had no effect, and methoxamine caused constriction only at a very high dose. it is conclude ... | 1985 | 3837030 |
| location and function of voltage-sensitive conductances in retinal rods of the salamander, ambystoma tigrinum. | the functional role and spatial location of voltage-sensitive conductances that modify the light-evoked electrical signals were studied in retinal rods of the tiger salamander. an isolated rod was drawn into a suction electrode for recording membrane current and impaled with an intracellular electrode for recording membrane potential and passing current. a bright flash gave a rapid initial hyperpolarization that relaxed to a smaller plateau. simultaneously the dark current of the outer segment w ... | 1984 | 6481634 |
| pressure injection of 3',5'-cyclic gmp into solitary rod photoreceptors of the tiger salamander. | the outer segments of solitary rods of large neotenic ambystoma tigrinum were impaled with double-barrel micropipettes. one barrel was used to record membrane voltage and the other barrel was used both to pass voltage-clamp current and to pressure-inject cyclic gmp. injections of cyclic gmp induced inward currents in normal cells that were bathed in ringer's solution and studied at the dark, resting voltage. these cyclic gmp-induced currents reversed sign for voltages 25-40 mv more positive than ... | 1984 | 6331582 |
| topographic coding of odorant quality is maintained at different concentrations in the salamander olfactory epithelium. | in a recent study in the tiger salamander, ambystoma tigrinum, were demonstrated topographic patterns of responsivity across the olfactory epithelium which were characteristic for each odorant. the present study was initiated to investigate whether these patterns remain constant when odorant concentration is varied. odorant-induced electro- olfactograms were recorded from at least 12 sites on each epithelium. the odorants used were pinene, amyl acetate and propanol. each epithelium was tested wi ... | 1984 | 6722540 |
| temperature sensitivity of the renin-angiotensin system in ambystoma tigrinum. | the presence of a renin-angiotensin system was demonstrated in the poikilotherm ambystoma tigrinum, commonly called the tiger salamander. standard radioimmunoassay techniques were employed to measure the intrarenal renin activity (ira) and the plasma renin activity (pra) of a. tigrinum kept at either 5 or 20 degrees c. basal ira and pra values were not affected by the temperature at which the animals were maintained. intraperitoneal injection of the beta-adrenergic agonist isoproterenol, however ... | 1984 | 6372514 |
| absorptance and spectral sensitivity measurements of rod photoreceptors of the tiger salamander, ambystoma tigrinum. | the spectral sensitivity of the extracellularly-recorded photoresponse of isolated rods of the tiger salamander, ambystoma tigrinum, was compared to the absorptance spectrum. both measurements were made with the same optical system on the same portion of each cell to avoid errors that could occur when the two kinds of measurement were made under different conditions. the relative spectral sensitivity and absorptance spectrum were found to be in excellent agreement between 450 and 700 nm. | 1984 | 6533990 |
| regional differences in cell density and cell genesis in the olfactory epithelium of the salamander, ambystoma tigrinum. | the olfactory epithelium undergoes continuous regeneration. the present quantitative study uses tritiated thymidine autoradiography to investigate regional differences in the rate of olfactory epithelial cell genesis in the tiger salamander. there was a significant gradient in the incorporation of thymidine from the posterior to the anterior in the nasal cavity: the posterior epithelium underwent cell genesis much faster than the anterior. additionally, the posterior epithelium was thinner and c ... | 1984 | 6519235 |
| the projection from the olfactory epithelium to the olfactory bulb in the salamander, ambystoma tigrinum. | odor quality may be represented as a "topographic" code of responses of receptor cells throughout the olfactory epithelium, with this code conveyed to the central nervous system by a topographic projection from the olfactory epithelium to the olfactory bulb. there is good evidence for topographic differences in odor-induced receptor cell activity in the tiger salamander but there is no evidence for a topographic epithelium-to-bulb projection in this species. in the present study 3h-leucine autor ... | 1984 | 6089611 |
| intracellular ph regulation in the renal proximal tubule of the salamander. basolateral hco3- transport. | we have used ph-, na-, and cl-sensitive microelectrodes to study basolateral hco3- transport in isolated, perfused proximal tubules of the tiger salamander ambystoma tigrinum. in one series of experiments, we lowered basolateral ph (phb) from 7.5 to 6.8 by reducing [hco3-]b from 10 to 2 mm at a constant pco2. this reduction of phb and [hco3-]b causes a large (approximately 0.35), rapid fall in phi as well as a transient depolarization of the basolateral membrane. returning phb and [hco3-]b to no ... | 1983 | 6833997 |
| intracellular ph regulation in the renal proximal tubule of the salamander. na-h exchange. | using ph-sensitive microelectrodes to measure intracellular ph (phi) in isolated, perfused proximal tubules of the tiger salamander ambystoma tigrinum, we have found that when cells are acid-loaded by pretreatment with nh+4 in a nominally hco3--free ringer, phi spontaneously recovers with an exponential time course. this phi recovery, which is indicative of active (i.e., uphill) transport, is blocked by removal of na+ from both the luminal and basolateral (i.e., bath) solutions. re-addition of n ... | 1983 | 6833996 |
| distribution of monoamine oxidase activity in tissues of the urodeles ambystoma tigrinum (tiger salamander) and necturus maculosus (mudpuppy). | 1. monoamine oxidase (mao) activity was determined fluorometrically in tissues of adult mudpuppies, and pre- (young) and post- (adult) metamorphic tiger salamanders. 2. from responses to specific inhibitors it was determined that 95% activity was mao type a in all tissues. 3. in young salamanders mao activity was greater in brain and intestine of males than of females, and was considerably higher in kidney of both sexes and in intestine of males compared to adults. 4. mao activity was distribute ... | 1983 | 6132771 |
| mechanisms of underwater hearing in larval and adult tiger salamanders ambystoma tigrinum. | 1. a standing wave tube apparatus was used to determine the biophysical basis of underwater hearing in ambystoma tigrinum. 2. a. tigrinum responds to the pressure component of underwater sound, and the mouth cavity appears responsible for transduction of sound pressure. 3. near-field displacements produced by pulsations of the air-filled mouth cavity apparently stimulate the inner ear. 4. salamander head preparations with no air-filled mouth cavity respond to the particle motion component of und ... | 1983 | 6132703 |
| temporary and selective anosmia in tiger salamanders (ambystoma tigrinum) caused by chemical treatment of the olfactory epithelium. | tiger salamanders (ambystoma tigrinum) were trained to respond to two dissimilar odorants (i.e., cyclohexanone, dimethyl disulfide) but not to a third odorant (n-butanol). when the training criterion was met, the animals were anesthetized and given nasal lavages of saline or odorants in saline. lavage with cyclohexanone decreased responding to cyclohexanone but not dimethyl disulfide, and vice-versa, in later behavioral tests. likewise, ethyl acetoacetate lavage produced selective response decre ... | 1982 | 7178276 |
| voltage-activated and calcium-activated currents studied in solitary rod inner segments from the salamander retina. | 1. solitary rod inner segments were obtained by enzymatic dissociation of the tiger salamander (ambystoma tigrinum) retina. their membrane currents were studied with the single-pipette voltage-clamp technique. individual currents were isolated with the aid of pharmacological agents.2. extracellular caesium blocked a current activated by hyperpolarization from -30 mv. changing external sodium and potassium concentrations altered the value of the reversal potential in a manner consistent with the ... | 1982 | 7153904 |
| heterogeneity in the distal nephron of the salamander (ambystoma tigrinum): a correlated structure function study of isolated tubule segments. | studies on isolated perfused tubules of the tiger salamander (ambystoma tigrinum) have shown that the distal nephron is heterogeneous with respect to function (stoner, 1977). in this study, the initial portion of the distal tubule (diluting segment) exhibited a voltage, positive in the lumen, and a net absorption of chloride. since the chloride was transported against an electro-chemical gradient, its transport was active. more distad, the junctional segment exhibited a lumen-negative voltage an ... | 1982 | 7149280 |
| allozyme heterozygosity and growth in the tiger salamander, ambystoma tigrinum. | statistically significant, positive correlations were found between individual heterozygosity at seven protein polymorphisms and size in five natural populations of tiger salamanders. when these same populations were sampled later in the same year, the positive associations between heterozygosity and size were no longer evident. a pair mating was conducted in the laboratory, and offspring were distributed randomly to four replicate populations maintained in the laboratory. in two to these four r ... | 2006 | 7108182 |
| spatial pattern of sensory cell terminals in the olfactory sac of the tiger salamander. i. a scanning electron microscope study. | the olfactory sac of adult tiger salamanders (ambystoma tigrinum) was assessed by scanning electron microscopy and the hitherto unknown variety of the olfactory sac cells has been documented. regional differences in respect to the composition of the apical epithelial surface border in the olfactory sac have been recorded. transitions between the olfactory epithelium proper and epithelia with different surface structures have been described. it has been shown that both the roof and the floor of t ... | 1982 | 7130039 |
| diurnal and seasonal variations in thyroid function of neotenic tiger salamanders (ambystoma tigrinum). | | 1981 | 7197245 |
| discrimination and generalization among reagent grade odorants by tiger salamanders (ambystoma tigrinum). | | 1981 | 7267751 |
| allopurinol-induced melanism in the tiger salamander (ambystoma tigrinum nebulosum). | the enzyme, xanthine dehydrogenase (xdh), has been examined in ambystoma tigrinum nebulosum with respect to its role in pigmentation. it now seems probable that the melanoid gene (m) either codes directly for xdh or is somehow intimately connected with the normal function of this enzyme. inhibition of xdh using the drug, allopurinol, results in animals which appear to be phenocopies of melanoid mutants as described for the mexican axolotl (ambystoma mexicanum). the effects of allopurinol in term ... | 1979 | 490138 |
| reduction of sodium dependent stump currents disturbs urodele limb regeneration. | we have asked the question whether the natural electric currents which leave urodele limb stumps are in any way needed for their regeneration. as an initial test, we have greatly reduced such currents in the tiger salamander, ambystoma tigrinum, by applying 0.5 mm amiloride to the stump skin or by immersion of the animals in sodium depleted media. we have also reduced such currents in the red spotted newt, notophthalmus viridescens, by such immersion. limb regeneration in half of the amiloride-t ... | 1979 | 490133 |
| plasma melatonin in the neotenic tiger salamander (ambystoma tigrinum): effects of photoperiod and pinealectomy. | | 1979 | 573224 |
| the relationship of a monoamine fiber system to a somatosensory tectal projection in the salamander ambystoma tigrinum. | after hemisection of the spinal cord and medulla oblongata, a projection has been traced to the inner half of the tectal white of the tiger salamander, using fink-heimer degeneration staining. by microelectrode recording it was found that the tectal projection forms a topographic somatosensory map of the contralateral half of the body. this map is in register with the overlying retino-tectal visual projection. using the falck-hillarp technique, it was found that the somatosensory tectal input is ... | 1978 | 691065 |
| responses to light of solitary rod photoreceptors isolated from tiger salamander retina. | single, isolated rod photoreceptors were obtained by enzymatic dissociation of the tiger salamander (ambystoma tigrinum) retina. these solitary cells retained the morphological features of rods of the intact retina and could be maintained in culture for several days. when impaled with micropipettes for electrophysiological recording, dark-adapted solitary rods had during darkness a resting potential of approximately -45 mv and a steady-state slope resistance of 500 momega at rest. the current-vo ... | 1978 | 277954 |
| thyroid function in pre- and postspawning neotenic tiger salamanders (ambystoma tigrinum). | | 1977 | 598694 |
| position discrimination in the salamander, ambystoma tigrinum. | twenty larval tiger salamanders (ambystoma tigrinum) were collected from a playa lake in west texas and maintained in the laboratory for 7 days prior to the beginning of position training. ten subjects in the larval state were trained on a position problem in a t-maze for 5 trials per day to a criterion of 80% correct responses, using a self-correction procedure. following metamorphosis to the adult stage, these subjects were tested for retention. the remaining 10 subjects were allowed to metamo ... | 1977 | 873065 |
| telencephalic efferents of the tiger salamander ambystoma tigrinum tigrinum (green). | the efferent projections of the telencephalon in the tiger salamander were examined by the nauta and fink-heimer methods following unilateral hemispherectomies, rostral hemispheric ablations and pallial lesions. the cerebral hemisphere connects with most areas of the contralateral hemisphere via the pallial, anterior and habenular commissures. the descending fibers travel in the medial and lateral forebrain bundles and in the tracts comprising the stria medullaris. degenerating fibers and termin ... | 1977 | 864026 |
| neoplastic and possibly related skin lesions in neotonic tiger salamanders from a sewage lagoon. | tiger salamanders (ambystoma tigrinum) inhabiting a sewage sedimentation lagoon become neotenic, and approximately one-third develop neoplastic skin lesions including cancer. circumstances suggest a chemical etiology for the neoplasms. | 1977 | 847473 |
| histological, histochemical and electron microscopical studies on the nervous apparatus of the pineal organ in the tiger salamander, ambystoma tigrinum. | 150-190 photoreceptor cells form a basic structural component of the pineal organ of ambystoma tigrinum. most of the outer and inner segments of these cells project into the lumen horizontally. only 10% of the total number of photoreceptor cells are located within the pineal roof which is composed of a single cell layer. the photoreceptor cells are connected with nerve cells by synapses displaying characteristic ribbons. different types of synaptic contacts, i.e. simple, tangential, dyad, triad ... | 1976 | 1000587 |
| olfactory epithelium of necturus maculosus and ambystoma tigrinum. | the morphological study presented here provides a general description of the elements of the olfactory epithelium in the mud puppy and tiger salamander,, and gives evidence about their dynamic activity and interrelationships. there are morphological indications of local bursts of reduplication and a continual line of differentiation of receptor cells from basal cell progenitors through stages of mature development to senescence (indicated by the accumulation of pigment granules) and cell death a ... | 1976 | 1249589 |
| tumorous growths of the tiger salamander, ambystoma tigrinum, associated with treated sewage effluent. | | 1976 | 981691 |
| adaptation of the tiger salamander, ambystoma tigrinum, to arid habitats. | | 1973 | 4148158 |
| neurotransmitter synthesis in the tectum of the tiger salamander ambystoma tigrinum. | | 1973 | 4149307 |
| effects of pituitary hormones, melatonin, and thyroidal inhibitors on radioiodide uptake by the thyroid glands of larval and adult tiger salamanders, ambystoma tigrinum (amphibia: caudata). | | 1973 | 4753365 |
| spatial orientation by salamanders using plane-polarized light. | tiger salamanders (ambystoma tigrinum) can perceive the plane of polarization in linearly polarized light and can learn to use that e-vector direction for spatial orientation in indoor orientation tests. | 1973 | 4719070 |
| optic fiber projections of the tiger salamander ambystoma tigrinum. | | 1973 | 4791442 |
| coccidia from the tiger salamander, ambystoma tigrinum, in northeastern colorado and in northern new mexico. | | 1972 | 5032222 |
| retinal projections in the tiger salamander, ambystoma tigrinum. | | 1972 | 4121311 |
| spiroxys utahensis sp. n. (nematoda: spiruridae) from the tiger salamander, ambystoma tigrinum nebulosum. | | 1969 | 5813532 |
| polydactyly and limb duplication occurring naturally in the tiger salamander, ambystoma tigrinum. | | 1947 | 17741555 |
| incidence of serum sickness after the administration of australian snake antivenom (asp-22). | serum sickness is a delayed immune reaction resulting from the injection of foreign protein or serum. antivenom is known to cause serum sickness but the incidence and characteristics are poorly defined. | 2016 | 26490786 |
| health and rapid economic change in the late twentieth century. | rapidly expanding economies, such as the post-war tiger economies, are associated with increasing health and rapidly contracting economies, such as central and eastern europe in the early 1990s, are associated with declining health. in central and eastern europe health decline in association with economic contraction has been mediated by changes in income distribution and, also, by health-determining aspects of civil society. the nations of central and eastern europe are an example of swift econ ... | 2000 | 10972426 |
| binturong (arctictis binturong) and kinkajou (potos flavus) digestive strategy: implications for interpreting frugivory in carnivora and primates. | exclusive frugivory is rare. as a food resource, fruit is temporally and spatially patchy, low in protein, and variable in terms of energy yield from different carbohydrate types. here, we evaluate the digestive physiology of two frugivorous carnivora species (potos flavus, arctictis binturong) that converge with primates in a diversity of ecological and anatomical traits related to fruit consumption. we conducted feeding trials to determine mean digestive retention times (mrt) on captive animal ... | 2014 | 25157614 |
| some like it hot: thermal tolerance and oxygen supply capacity in two eurythermal crustaceans. | thermal sensitivity of the cardiorespiratory oxygen supply capacity has been proposed as the cardinal link underlying the upper boundary of the temperature niche in aquatic ectotherms. here we examined the evidence for this link in two eurythermal decapods, the giant tiger shrimp (penaeus monodon) and the european crayfish (astacus astacus). we found that both species have a temperature resistant cardiorespiratory system, capable of maintaining oxygen delivery up to their upper critical temperat ... | 2015 | 26030412 |
| species composition of by-catch from milkfish (chanos chanos) fry fishery in selected sites in the philippines as determined by dna barcodes. | milkfish fry fishery, an important industry in the philippines, uses non-selective fishing gears and push nets in coastal areas which lead to the capture of other non-targeted juvenile aquatic species. unfortunately, information on the amount and the identity of by-catch species is lacking thus the extent of impact of the fry fishery is not known. in this study, the species composition of milkfish fry fishery by-catch sampled from selected coastal areas that are known to be fry collection sites ... | 2016 | 25329278 |
| detection of venom-antivenom (vav) immunocomplexes in vitro as a measure of antivenom efficacy. | the measurement of free venom with enzyme immunoassay in serum of patients with snake envenoming is used to confirm snake identification and to determine if sufficient antivenom has been given. recent studies with russell's viper (rv; daboia russelii) envenoming have detected free venom post-antivenom despite recovery of coagulopathy. this raises the question as to whether this assay also measures venom-antivenom (vav) complexes. in this study we developed an assay to measure vav complexes and i ... | 2014 | 24252422 |
| responses of mitral/tufted cells to orthodromic and antidromic electrical stimulation in the olfactory bulb of the tiger salamander. | 1. responses evoked by electrical stimulation of the olfactory nerve and olfactory tracts were analyzed in 46 output cells of the salamander olfactory bulb, in vivo. labeling of several cells with horseradish peroxidase indicated that they were mitral and/or tufted neurons. the responses contained reproducible sequences of depolarizing and hyperpolarizing potentials, which changed with increases in stimulus intensity. 2. stimulation of the nerve with intensities subthreshold for evoking spikes i ... | 1988 | 3404202 |
| contacts between receptors and electrophysiologically identified neurones in the retina of the larval tiger salamander. | 1. following the intracellular recording of bipolar and horizontal cell responses, each unit was injected with horseradish peroxidase and a histochemical staining used to identify it at the level of the light and electron microscopes.2. centre-depolarizing bipolar cells made contact with rods and cones at basal and ribbon junctions, the latter being fewer. centre-hyperpolarizing bipolar cells made the same types of contacts with the receptors, but ribbon junctions predominated.3. it appears, the ... | 1978 | 217992 |
| density and carrying capacity in the forgotten tigerland: tigers in understudied nepalese churia. | while there are numerous wildlife ecology studies in lowland areas of nepal, there are no in-depth studies of the hilly churia habitat even though it comprises 7,642 km(2) of potential wildlife habitat across the terai arc. we investigated tiger, leopard, and prey densities across this understudied habitat. our camera trapping survey covered 536 km(2) of churia and surrounding areas within chitwan national park (cnp). we used 161 trapping locations and accumulated 2,097 trap nights in a 60-day s ... | 2016 | 27734629 |
| effect of human disturbance on the prey of tiger in the chitwan national park--implications for park management. | chitwan national park is surrounded by large settlements of people who exploit the areas where tigers and their prey occur. in this study, we measured the associations between the abundance of the prey of tiger with habitat, topographic, predator and human disturbance variables, using canonical correspondence analysis. we show that the abundance of hog deer is closely associated with areas of tall grassland and floodplains, while that of other ungulate species is associated with that of forests ... | 2013 | 24211382 |
| influence of dietary fiber type and amount on energy and nutrient digestibility, fecal characteristics, and fecal fermentative end-product concentrations in captive exotic felids fed a raw beef-based diet. | little nutritional or metabolic information has been collected from captive exotic cats fed raw diets. in particular, fiber types and concentrations for use in raw meat-based diets for captive exotic felids have not been well studied. our objective was to evaluate the effects of fiber type and concentration on apparent total tract energy and macronutrient digestibility, fecal characteristics, and fecal fermentative end-products in captive exotic felids. four animals of each captive exotic specie ... | 2013 | 23463568 |
| skin lipid structure controls water permeability in snake molts. | the role of lipids in controlling water exchange is fundamentally a matter of molecular organization. in the present study we have observed that in snake molt the water permeability drastically varies among species living in different climates and habitats. the analysis of molts from four snake species: tiger snake, notechis scutatus, gabon viper, bitis gabonica, rattle snake, crotalus atrox, and grass snake, natrix natrix, revealed correlations between the molecular composition and the structur ... | 2014 | 24157843 |
| effects of developmental temperature on gametocysts and oocysts of two species of gregarines blabericola migrator and blabericola cubensis (apicomplexa: eugregarinida: blabericolidae) parasitizing blaberid cockroaches (dictyoptera: blaberidae). | abiotic environmental conditions, especially temperature and humidity, have profound effects on the growth and development of gregarines, but these effects remain largely undocumented. quantifying the effects of environmental conditions on the growth and development of exogenous gregarine ontogenetic stages is an important first step in understanding the transmission, population dynamics, and environmental persistence of gregarine infection. in this study, we examined the effect of 6 environment ... | 2015 | 26248890 |
| biological aspects of sharks caught off the coast of pernambuco, northeast brazil. | one hundred seventeen specimens of sharks were caught along the coast of pernambuco state, northern brazil, between may 2004 and may 2007, among which 86 were blacknose sharks, carcharhinus acronotus, enabling a more detailed study of the species. blacknose sharks were caught in the 2 study areas along the boa viagem/piedade and paiva beaches, accounting for the highest relative abundance among the species caught (73.5% of total). potentially dangerous sharks, tiger and bull sharks, were also ca ... | 2009 | 19967190 |
| functional nonredundancy of elephants in a disturbed tropical forest. | conservation efforts are often motivated by the threat of global extinction. yet if conservationists had more information suggesting that the local extirpation of individual species could lead to undesirable ecological effects, conservationists might more frequently attempt to protect or restore such species across their range even if they are not in danger of global extinction. scientists have seldom measured or quantitatively predicted the functional consequences of species loss, even for larg ... | 2017 | 28218805 |
| wild versus domestic prey in the diet of reintroduced tigers (panthera tigris) in the livestock-dominated multiple-use forests of panna tiger reserve, india. | grazing livestock in openly accessible areas is a common practice in the multiple-use forests of india; however, its compatibility with the reintroduction of tigers to these areas requires examination. here, we investigated the diet of tigers in a livestock-dominated multiple-use buffer zone of the panna tiger reserve, india. we hypothesised that the presence of feral cattle, along with open-access grazing practices in multiple-use forests, would increase the incidence of predation on livestock ... | 2017 | 28379997 |
| pioneer identification of fake tiger claws using morphometric and dna-based analysis in wildlife forensics in india. | the illegal trade in wildlife is a serious threat to the existence of wild animals throughout the world. the short supply and high demand for wildlife articles have caused an influx of many different forms of fake wildlife articles into this trade. the task of identifying the materials used in making such articles poses challenges in wildlife forensics as different approaches are required for species identification. claws constitute 3.8% of the illegal animal parts (n=2899) received at the wildl ... | 2016 | 27322503 |
| integrating occupancy models and structural equation models to understand species occurrence. | understanding the drivers of species occrrece s a fundamenal goal in basic and applied ecology. occupancy models have emerged as a popular approach for inferring species occurrence because they account for problems associated with imperfect detection in field surveys. current models, however, are limited because they assume covariates are independent (i.e., indirect effects do not occur). here, we combined structural equation and occupancy models to investigate complex influences on species occu ... | 2016 | 27197402 |
| [comparative analysis five kinds of serological detection methods about brucella]. | to evaluation the specificity and sensitivity of 5 kinds of serological detection methods about brucellosis. | 2016 | 26926728 |
| expression of penaeus monodon ortholog of niemann-pick type c-2 in the spermatic tract, and its role in sperm cholesterol removal. | protein and lipid composition of sperm plasma membrane are modified as these gametes continue to mature during their transit along the spermatic tract. our previous study revealed that during its journey through the spermatic duct of the black tiger prawn, penaeus monodon, sperm cholesterol content decreases through the action of lipid-binding proteins within the luminal environment. in this study, the full cdna sequence of epididymal secretory protein e1 (he1), or niemann-pick c2 (npc2), was cl ... | 2016 | 26822874 |
| in the elephant's seed shadow: the prospects of domestic bovids as replacement dispersers of three tropical asian trees. | as populations of the world's largest animal species decline, it is unclear how ecosystems will react to their local extirpation. due to the unique ecological characteristics of megaherbivores such as elephants, seed dispersal is one ecosystem process that may be affected as populations of large animals are decimated. in typically disturbed south asian ecosystems, domestic bovids (cattle, bosprimigenius, and buffalo, bubalus bubalis) may often be the species most available to replace asian eleph ... | 2015 | 26405735 |
| endoparasites in cattle nearby tribal areas of free-ranging protected areas of tamil nadu state. | fresh dung samples from cattle nearby and tribal areas of free-ranging regions, mudumalai tiger reserve, anamalai tiger reserve and forest divisions of sathyamangalam-erode of tamil nadu state were examined for identification of endoparasitic infection. a total of 50 dung samples were collected and examination of samples revealed the presence of eggs of strongyle, strongyloides sp., amphistomes, toxocara sp. and oocysts of eimeria sp. the risk of parasitic disease transmission from domestic live ... | 2014 | 25320498 |
| [effects of the periodical spread of rinderpest on famine, epidemic, and tiger disasters in the late 17th century]. | this study clarifies the causes of the repetitive occurrences of such phenomena as rinderpest, epidemic, famine, and tiger disasters recorded in the joseon dynasty chronicle and the seungjeongwon journals in the period of great catastrophe, the late 17th century in which the great gyeongsin famine (1670~1671) and the great eulbyeong famine (1695~1696) occurred, from the perspective that they were biological exchanges caused by the new arrival of rinderpest in the early 17th century. it is an obj ... | 2014 | 24804681 |
| the implications of habitat management on the population viability of the endangered ohlone tiger beetle (cicindela ohlone) metapopulation. | despite their role in providing ecosystem services, insects remain overlooked in conservation planning, and insect management approaches often lack a rigorous scientific basis. the endangered ohlone tiger beetle (cicindela ohlone) occurs in a 24-km(2) area in santa cruz county, california. the once larger metapopulation now consists of subpopulations inhabiting five patches of coastal prairie where it depends on bare ground for mating, foraging, and oviposition. human activities have eliminated ... | 2013 | 23951067 |
| patterns of top-down control in a seagrass ecosystem: could a roving apex predator induce a behaviour-mediated trophic cascade? | 1. the loss of large-bodied herbivores and/or top predators has been associated with large-scale changes in ecosystems around the world, but there remain important questions regarding the contexts in which such changes are most likely and the mechanisms through which they occur, particularly in marine ecosystems. 2. we used long-term exclusion cages to examine the effects of large grazers (sea cows, dugong dugon; sea turtles chelonia mydas) on seagrass community structure, biomass and nutrient d ... | 2013 | 23730871 |
| the coagulation of blood by snake venoms and its physiologic significance. | nine of the 17 venoms here tested were found capable of coagulating citrated blood or plasma. as has been believed by most workers in the field, 7 of these 9 coagulant venoms convert fibrinogen to an insoluble modification resembling fibrin (bothrops atrox, bothrops jararaca, bothrops nummifera, crotalus adamanteus, crotalus horridus, crotalus terrificus basiliscus, crotalus terrificus terrificus). the optimum ph for this coagulation was determined for 3 of these, and was found in each case to b ... | 1937 | 19870622 |
| successful use of camelid (alpaca) antivenom to treat a potentially lethal tiger snake (notechis scutatus) envenomation in a dog. | this report describes a confirmed clinical case of tiger snake (notechis scutatus) envenomation in a domestic dog that was successfully treated with a novel polyvalent camelid (alpaca; llama pacos) antivenom. samples collected from the dog were assayed for tiger snake venom (tsv) using a highly sensitive and specific elisa. the tsv concentration in serum and urine at initial presentation was 365 ng/ml and 11,640 ng/ml respectively. at the time of initial presentation whole blood collected from t ... | 2016 | 26930223 |
| fatal presumed tiger snake (notechis scutatus) envenomation in a cat with measurement of venom and antivenom concentration. | a fatal outcome of a presumed tiger snake (notechis scutatus) envenomation in a cat is described. detectable venom components and antivenom concentrations in serum from clotted and centrifuged whole blood and urine were measured using a sensitive and specific elisa. the cat presented in a paralysed state with a markedly elevated serum ck but with normal clotting times. the cat was treated with intravenous fluids and received two vials of equine whole igg bivalent (tiger and brown snake) antiveno ... | 2016 | 26836396 |
| serologic survey of trichinellosis in wild mammals kept in a mexico city zoo. | a serologic survey of trichinella infection was carried out to determine the prevalence of this parasitosis among wild mammals kept in captivity at the chapultepec zoo. this was prompted by the necropsy finding of a heavy trichinella infection in a canadian polar bear (ursus maritimus) that had been kept at the zoo for more than 11 years. the parasites recovered were identified as t. nativa (t2). a serologic study based on elisa and western blot analysis was performed in serum samples from two p ... | 1996 | 9017871 |
| molecular detection of tick-borne bacterial agents in brazilian and exotic captive carnivores. | the present study aims to detect and characterize by molecular techniques, the presence of tick-borne pathogens in wild captive carnivore blood samples from brazil. blood was collected from 76 brazilian felids, 23 exotic felids, 3 european wolves (canis lupus), and 97 brazilian canids maintained in captivity in zoos located in são paulo and mato grosso states, brazil. dna of each sample was used in pcr reactions for ehrlichia, anaplasma, and rickettsia identification. the blood from 10/100 (10%) ... | 2012 | 22749737 |
| the predatory behaviour of the thylacine: tasmanian tiger or marsupial wolf? | the extinct thylacine (thylacinus cynocephalus) and the extant grey wolf (canis lupus) are textbook examples of convergence between marsupials and placentals. craniodental studies confirm the thylacine's carnivorous diet, but little attention has been paid to its postcranial skeleton, which would confirm or refute rare eyewitness reports of a more ambushing predatory mode than the pack-hunting pursuit mode of wolves and other large canids. here we show that thylacines had the elbow morphology ty ... | 2011 | 21543392 |
| pennsylvania's hcccc (health care cost containment council): cost/quality watchdog or paper tiger? | | 1991 | 10115135 |
| prey depletion as a threat to the world's large carnivores. | large terrestrial carnivores are an ecologically important, charismatic and highly endangered group of species. here, we assess the importance of prey depletion as a driver of large carnivore endangerment globally using lists of prey species for each large carnivore compiled from the literature. we consider spatial variation in prey endangerment, changes in endangerment over time and the causes of prey depletion, finding considerable evidence that loss of prey base is a major and wide-ranging th ... | 2016 | 27853599 |
| tiger blood and goat milk. | | 2016 | 27348384 |
| carnivore fecal chemicals suppress feeding by alpine goats (capra hircus). | the efficacy of carnivore and ungulate fecal chemicals in suppressing the feeding behavior of alpine goats (capra hircus) was examined. in the first four experiments, goats were offered food covered with paper strips treated with fecal extracts of the bengal tiger, siberian tiger, african lion, and brown bear, respectively; food covered with solvent-treated and untreated (plain) papers served as controls in each experiment. goats made fewer head entries into, and ate less food from, buckets cont ... | 1993 | 24248787 |
| mercury contamination in commercial fresh and salt water fish of the zabol chahnimeh reservoirs and the gulf of oman (iran). | in order to investigate bioaccumulation of mercury in iranian coastal waters fish, tiger tooth croaker (otolithes ruber) and yellowspotted trevally (carangoides fulvoguttatus) from the gulf of oman and grass carp (ctenopharyngodon idella) and silver carp (hypophthalmichthys molitrix) from zabol chahnimeh reservoirs were sampled in may 2012. in these ecosystems, total mercury concentrations were measured in muscle and gill of these four fish species. both regions did not reveal a significant diff ... | 2013 | 24779901 |
| isolation and characterization of eight microsatellite loci from galeocerdo cuvier (tiger shark) and cross-amplification in carcharhinus leucas, carcharhinus brevipinna, carcharhinus plumbeus and sphyrna lewini. | the tiger shark galeocerdo cuvier (carcharhinidae) is a large elasmobranch suspected to have, as other apex predators, a keystone function in marine ecosystems and is currently considered near threatened (red list iucn). knowledge on its ecology, which is crucial to design proper conservation and management plans, is very scarce. here we describe the isolation of eight polymorphic microsatellite loci using 454 gs-flx titanium pyrosequencing of enriched dna libraries. their characteristics were t ... | 2016 | 27231661 |
| relative abundance and size of coastal sharks derived from commercial shark longline catch and effort data. | in the north-west atlantic ocean, stock assessments conducted for some commercially harvested coastal sharks indicate declines from 64 to 80% with respect to virgin population levels. while the status of commercially important species is available, abundance trend information for other coastal shark species in the north-west atlantic ocean are unavailable. using a generalized linear modelling (glm) approach, a relative abundance index was derived from 1994 to 2009 using observer data collected i ... | 2012 | 22497406 |
| a comparison of the heart and muscle total lipid and fatty acid profiles of nine large shark species from the east coast of south africa. | we have assessed the fatty acid profiles of the hearts and different muscle tissues from nine large shark species (carcharhinus limbatus (blacktip), carcharhinus obscurus (dusky), carcharhinus brevipinna (spinner), carcharhinus leucas (zambezi/bull), galeocerdo cuvier (tiger), sphyrna lewini (scalloped hammerhead), sphyrna zygaena (smooth hammerhead), carcharodon carcharias (great white) and carcharias taurus (raggedtooth/grey nurse/sand tiger)) found off the east coast of south africa. while th ... | 2011 | 20694746 |