eimeria from bats of the world. ii. a new species in tadarida femorosacca from sonora, mexico.between 1979 and 1980, 104 bats representing 13 species in 4 families were collected in california and new mexico, u.s.a., and baja california and sonora, mexico, and were examined for coccidia; only 3 (3%) had oocysts in their feces. bats examined and their infection rates were: molossidae: 0 of 12 tadarida brasiliensis, 1 of 18 (6%) t. femorosacca; natalidae: 0 of 1 natalus stramineus; phyllostomatidae: 0 of 1 choeronycteris mexicana, 0 of 2 leptonycteris sanborni, 0 of 1 macrotus californicus ...19883357122
the primary structure of the pallid bat (antrozous pallidus, chiroptera) hemoglobin.the complete primary structure of the hemoglobin from the pallid bat (antrozous pallidus, microchiroptera) is presented. this hemoglobin consists of two components with identical amino-acid sequences, differing, however, in the n-terminus which is formylated in 12.5% of the beta-chains. the alpha- and beta-chains were separated by reversed phase high performance liquid chromatography. the sequences of both chains were established by automatic edman degradation with the film technique or gas phas ...19873675871
the primary structure of the hemoglobin from the lobe-lipped bat (chalinolobus morio, microchiroptera).the hemoglobin of the lobe-lipped bat (chalinolobus morio, vespertilionidae) is composed of 45% hbi and 55% hbii. both components show identical alpha-chains but differ at the following three positions of their beta-chains: beta i/beta ii 21: glu/asp, 70: ser/ala, and 135: gln/leu. high performance liquid chromatography revealed pure alpha-chains and a mixture of only partly separated beta-chains. based on this material, the primary structures of all three globin chains could be achieved by auto ...19958590629
monaural and binaural spectral cues created by the external ears of the pallid bat.the acoustic properties of external ears transform the spectra of incident sound in a location-dependent manner, and provide monaural and binaural spectral information used in 2-dimensional localization. human studies suggest that binaural spectral differences, and spectral peaks and notches in monaural transfer functions, may all provide spatial information. this study examined the acoustic properties of the pallid bat ear to determine directionality, interaural intensity differences spectral p ...19968793503
eimeria from bats of the world: two new species from myotis spp. (chiroptera: vespertilionidae).between 1986 and 1995, 548 fecal samples were collected from 41 species of bats (molossidae, mormoopidae, phyllostomidae, thyropteridae, and vespertilionidae) from new mexico, california, baja california sur (mexico), and bolivia. of these, the feces of 28 (5%) bats, including antrozous pallidus, myotis ciliolabrum, myotis lucifugus, and myotis yumanensis (vespertilionidae), contained oocysts representing at least 3 species of eimeria. a new species of eimerian from m. lucifugus (3/27, 11%) and ...19979194833
six new eimeria species from vespertilionid bats of north america.twenty species of bats (molossidae, vespertilionidae) were collected from california, new mexico, oregon, south carolina, utah, and baja california norte (mexico), and 29 of 404 (7%) animals, including antrozous pallidus, eptesicus fuscus, myotis auriculus, myotis californicus, myotis ciliolabrum, myotis evotis, myotis lucifugus, myotis thysanodes, myotis vivesi, myotis volans, myotis yumanensis, and nycticeius humeralis were infected with eimeria spp., which represent 6 new species. sporulated ...199910386443
bat ectoparasites from the trans-pecos region of texas, including notes from big bend national park.ectoparasites of 13 species of molossid, mormoopid, and vespertilionid bats from the trans-pecos region of texas were studied, as follows: antrozous pallidus (leconte), corynorhinus townsendii (cooper), eptesicus fuscus (palisot de beauvois), lasiurus cinereus (palisot de beauvois), mormoops megalophylla (peters), myotis thysanodes g. s. miller, myotis velifer (j. a. allen), myotis volans (h. allen), myotis yumanensis (h. allen), nyctinomops femorosaccus (merriam), nyctinomops macrotis (gray), p ...200111372965
smooth muscle in the annulus fibrosus of the tympanic membrane in bats, rodents, insectivores, and humans.the annulus fibrosus and its attachment to the bony tympanic ring were studied in a series of mammals. in the pallid bat, antrozous pallidus, there is an extensive plexus of large interconnected blood sinuses in the part of the annulus that borders the tympanic bone. the spaces between the sinuses are packed with smooth muscle cells. most of the cells have a predominately radial orientation; they extend from the bony tympanic sulcus to a dense collagenous matrix (apical zone) where radially orie ...200515668036
neural mechanisms underlying selectivity for the rate and direction of frequency-modulated sweeps in the auditory cortex of the pallid bat.frequency-modulated (fm) sweeps are common in vocalizations, including human speech. selectivity for fm sweep rate and direction is present in the auditory cortex of many species. the present study sought to determine the mechanisms underlying fm sweep selectivity in the auditory cortex of pallid bats. in the pallid bat inferior colliculus (ic), two mechanisms underlie selectivity for fm sweep rate. the first mechanism depends on duration tuning for tones that arises as a consequence of early in ...200616775213
application of local heat induces capillary recruitment in the pallid bat blood flow increases in response to local heat due to sensorineural and nitric oxide (no)-mediated dilation. it has been previously demonstrated that arteriolar dilation is inhibited with no synthase (nos) blockade. flow, nonetheless, increases with local heat. this implies that the previously unexamined nonarteriolar responses play a significant role in modulating flow. we thus hypothesized that local heating induces capillary recruitment. we heated a portion (3 cm2) of the pallid bat wing ...200717332157
experience is required for the maintenance and refinement of fm sweep selectivity in the developing auditory cortex.frequency modulated (fm) sweeps are common components of vocalizations, including human speech. how developmental experience shapes neuronal selectivity for these important signals is not well understood. here, we show that altered developmental experience with fm sweeps used in echolocation by the pallid bat leads to either a loss of sideband inhibition or millisecond delays in the timing of inhibitory inputs, both of which lead to a reduction in rate and direction selectivity in auditory corte ...200818334643
microvascular control of capillary pressure during increases in local arterial and venous pressure.the extent to which capillary hydrostatic pressure might be protected from increases in local arterial and venous pressure was examined in the wing microcirculation of unanesthetized pallid bats (antrozous pallidus). arterial inflow and venous outflow pressures to the wing were elevated using a box technique to increase pressure around the body of the animal in steps of 12 mmhg between 0 and +60 mmhg for 3-min periods. during this time, hydrostatic pressure, diameter, and red cell velocity in si ...20113354702
matched behavioral and neural adaptations for low sound level echolocation in a gleaning bat, antrozous active sensing, animals make motor adjustments to match sensory inputs to specialized neural circuitry. here, we describe an active sensing system for sound level processing. the pallid bat uses downward frequency-modulated (fm) sweeps as echolocation calls for general orientation and obstacle avoidance. the bat's auditory cortex contains a region selective for these fm sweeps (fm sweep-selective region, fmsr). we show that the vast majority of fmsr neurons are sensitive and strongly selectiv ...201728275715
parvalbumin and calbindin expression in parallel thalamocortical pathways in a gleaning bat, antrozous pallidus.the pallid bat (antrozous pallidus) listens to prey-generated noise to localize and hunt terrestrial prey while reserving echolocation to avoid obstacles. the thalamocortical connections in the pallid bat are organized as parallel pathways that may serve echolocation and prey localization behaviors. thalamic inputs to the cortical echolocation call- and noise-selective regions originate primarily in the suprageniculate nucleus (sg) and ventral division of medial geniculate body (mgbv), respectiv ...201424435957
seasonal reliance on nectar by an insectivorous bat revealed by stable isotopes.many animals have seasonally plastic diets to take advantage of seasonally abundant plant resources, such as fruit or nectar. switches from insectivorous diets that are protein rich to fruits or nectar that are carbohydrate rich present physiological challenges, but are routinely done by insectivorous songbirds during migration. in contrast, insectivorous bat species are not known to switch diets to consume fruit or nectar. here, we use carbon stable isotope ratios to establish the first known c ...201424276770
insectivorous bat pollinates columnar cactus more effectively per visit than specialized nectar bat.plant-pollinator interactions are great model systems to investigate mutualistic relationships. we compared pollinator effectiveness between facultative and obligate nectar-feeding bats to determine how foraging specialization influences mutualistic interactions in a bat-adapted cactus. we predicted that a specialized nectarivorous bat would deliver more pollen than an opportunistic nectar-feeding bat because of specialized adaptations to nectar feeding that indicate close association with their ...201323234851
development of auditory thalamocortical connections in the pallid bat, antrozous pallidus.auditory thalamocortical connections are organized as parallel pathways originating in various nuclei of the medial geniculate body (mgb). the development of these pathways has not been studied. therefore it remains unclear whether thalamocortical connections segregate before the onset of hearing or whether refinement of exuberant thalamocortical connections occurs following hearing onset. we studied this issue in the pallid bat. in adult pallid bats, parallel thalamocortical pathways represent ...200919412955
parallel thalamocortical pathways for echolocation and passive sound localization in a gleaning bat, antrozous pallidus.we present evidence for parallel auditory thalamocortical pathways that serve two different behaviors. the pallid bat listens for prey-generated noise (5-35 khz) to localize prey, while reserving echolocation [downward frequency-modulated (fm) sweeps, 60-30 khz] for obstacle avoidance. its auditory cortex contains a tonotopic map representing frequencies from 6 to 70 khz. the high-frequency (bf > 30 khz) representation is dominated by fm sweep-selective neurons, whereas most neurons tuned to low ...200717111376
neural mechanisms underlying selectivity for the rate and direction of frequency-modulated sweeps in the inferior colliculus of the pallid bat.this study describes mechanisms that underlie neuronal selectivity for the direction and rate of frequency-modulated sweeps in the central nucleus of the inferior colliculus (icc) of the pallid bat (antrozous pallidus). this icc contains a high percentage of neurons (66%) that respond selectively to the downward sweep direction of the bat's echolocation pulse. some (19%) are specialists that respond only to downward sweeps. most neurons (83%) are also tuned to sweep rates. a two-tone inhibition ...200616790604
role of urea in the postprandial urine concentration cycle of the insectivorous bat antrozous pallidus.insectivorous bats, which feed once daily, produce maximally concentrated urine only after feeding. the role of urea as an osmolyte in this process was investigated in pallid bats (antrozous pallidus) in the laboratory. following a 24-h fast, plasma and urine were sampled before and 2 h after feeding in postprandial (pp) animals and before and 2 h after similar treatment without feeding in nonfed (nf) animals. food consumption by pp animals and handling of nf animals had no effect on blood water ...200415123201
can two streams of auditory information be processed simultaneously? evidence from the gleaning bat antrozous pallidus.a tenet of auditory scene analysis is that we can fully process only one stream of auditory information at a time. we tested this assumption in a gleaning bat, the pallid bat (antrozous pallidus) because this bat uses echolocation for general orientation, and relies heavily on prey-generated sounds to detect and locate its prey. it may therefore encounter situations in which the echolocation and passive listening streams temporally overlap. pallid bats were trained to a dual task in which they h ...200314564468
projection to the inferior colliculus from the basal nucleus of the amygdala.this report describes a projection from the amygdala, a forebrain center mediating emotional expression, to the inferior colliculus (ic), the midbrain integration center of the ascending auditory system. in the ic of mustached bats (pteronotus parnellii) and pallid bats (antrozous pallidus), we placed deposits of retrograde tracers at physiologically defined sites and then searched for retrogradely labeled somata in the forebrain. labeling was most sensitive in experiments using cholera toxin b- ...200212451144
phylogenetic position of eimeria antrozoi, a bat coccidium (apicomplexa: eimeriidae) and its relationship to morphologically similar eimeria spp. from bats and rodents based on nuclear 18s and plastid 23s rdna sequences.partial plastid 23s and nuclear 18s rdna genes were amplified and sequenced from 2 morphologically similar eimeria species. e. antrozoi from a bat (antrozous pallidus) and e. arizonensis from deer mice (peromyscus spp.), as well as some other eimeria species from bats and rodents. the phylogenetic trees clearly separated e. antrozoi from e. arizonensis. the phylogenies based on plastid 23s rdna data and combined data of both plastid and nuclear genes grouped 2 bat eimeria and 3 morphologically s ...200111695377
tick (acari) infestations of bats in new mexico.a total of 278 bats belonging to 16 species was examined for ticks from various sites in new mexico from 1994 to 1998. seven species of bats were parasitized by ticks: larvae of ornithodoros kelleyi cooley & kohls, ornithodoros rossi kohls, sonenshine & clifford (argasidae), or both. both species of ticks are reported from new mexico for the first time. infestation prevalences for parasitized bats ranged from 2 to 25% on different host species for o. kelleyi and from 7 to 25% for o. rossi. the p ...200111476346
algorithms for the generation of complex sounds for auditory physiology studies.the pallid bat (antrozous pallidus) is a member of a small class of bats known as gleaners. these bats use echolocation to avoid obstacles in flight while using passive listening to localize terrestrial prey. the echolocation pulses are 60-30 khz downward frequency modulated sweeps that last 3-5 milliseconds. the prey-generated sounds are broadband noise transients in the 5-35 khz range [1]. the frequency components of these sounds are beyond the range of commonly available sound cards, but the ...200111347447
acute sensitivity to interaural time differences in the inferior colliculus of a bat that relies on passive sound localization.gleaning bats rely on passive hearing to detect and localize terrestrial prey, and display remarkable accuracy in their passive sound localization. this study examines binaural processing in the inferior colliculus (ic) of the pallid bat (antrozous pallidus), a gleaner that attends to prey-generated noise transients to locate prey. the primary focus is to determine whether neurons in its lateral ic, a region that appears dedicated to passive localization, possess a level of sensitivity to intera ...19979259235
multicentric malignant lymphoma in a pallid bat.a 2.5-year-old, female pallid bat (antrozous pallidus) was captured in oregon (usa) in 1990 and later died in 1992. at the time of death, abdominal distension due to ascites, splenomegaly, and hepatomegaly, and a cheek mass were noted. based on histologic examination of these tissues, a diagnosis of multicentric lymphoma was made. retroviral particles were not found on electron microscopic examination.19968827686
predation pressure on an imperfect batesian micicry complex in the presence of alternative prey.differential predation pressure and the probability of predation on a batesian mimicry complex and on alternative prey were estimatedin a field experiment. the mimicry complex was composed of a noxious model (eleodes obscura (say)) and a palatable mimic (stenomorpha marginata (leconte)). house crickets (acheta domesticus) (linn.) were used as alternative prey. the experiment was conducted for 23 nights in august and september to approximate the peak seasonal activity time period during which bot ...198828312410
metabolic strategies of pallid bats (antrozous pallidus) during reproduction.both lactating and non-lactating pallid bats defend a high body temperature in a cool ambient temperature during the summer months by increasing their metabolism. metabolism decreased between august and september in captive females maintained under constant conditions and melatonin implants accelerated this shift from homeothermy to heterothermy. there appears to be an endogenous change in metabolism which can be accelerated by a rise in circulating melatonin levels.19863952176
photoperiod influences the annual reproductive cycle of the male pallid bat (antrozous pallidus).adult pallids bats collected in april or may, were maintained in short or long photoperiods (10 or 14 h light/day) for 3-6 months. in august, the short-day bats had regressed testes, epididymal spermatozoa and fully developed accessory sex glands, corresponding to the autumnal reproductive condition of field animals; long-day bats had testes undergoing spermatogenesis, few epididymal spermatozoa and undeveloped accessory sex glands (summer reproductive condition). bats in each photoperiod manife ...19846699816
postnatal changes in hematology of the bat antrozous pallidus.blood oxygen capacity increases with growth as the result of increasing hemoglobin concentration, which is accompanied by increasing red blood cell count and hematocrit. hematological profile of the postnatal bat approaches that of the adult by 42 days of age when the animal begins to fly. hematological development in the bat is similar to that in other altricial small mammals.19846149046
social effects of roosting on the metabolism of the pallid bat (antrozous pallidus). 19761003044
vocal communication in the pallid bat, antrozous pallidus.the communication sounds of the pallid bat, antrozous pallidus, wre studied in the laboratory. adult pallid bats communicate via four main types of sound emissions: directives, squabble notes, irritation buzzes, and fm orientation pulses. newborn bats emit only isolation calls. these calls evolve into the adult directive by the twentieth day. ultrasonic orientation pulses do not appear until 7--9 days postnatally. these appear to arise de novo or may be derived from a shortened isolation call. i ...1976961121
repeated homing exhibited by a female pallid bat.a pallid bat (antrozous pallidus) returned home from eight consecutive releases from six distinctly different directions and from distances ranging from 21 to 68 miles. this performance indicates that chance alone cannot be a major factor in homing, and that certain abilities possessed by this bat, and not simply randomness, must have been in operation.196217740812
arizona bark scorpion venom resistance in the pallid bat, antrozous pallidus.the pallid bat (antrozous pallidus), a gleaning bat found in the western united states and mexico, hunts a wide variety of ground-dwelling prey, including scorpions. anecdotal evidence suggests that the pallid bat is resistant to scorpion venom, but no systematic study has been performed. here we show with behavioral measures and direct injection of venom that the pallid bat is resistant to venom of the arizona bark scorpion, centruroides sculpturatus. our results show that the pallid bat is stu ...201728854259
functional segregation of monaural and binaural selectivity in the pallid bat auditory cortex.different fields of the auditory cortex can be distinguished by the extent and level tolerance of spatial selectivity. the mechanisms underlying the range of spatial tuning properties observed across cortical fields are unclear. here, this issue was addressed in the pallid bat because its auditory cortex contains two segregated regions of response selectivity that serve two different behaviors: echolocation for obstacle avoidance and localization of prey-generated noise. this provides the unique ...201627233917
mechanisms of sound localization in two functionally distinct regions of the auditory cortex.the auditory cortex is necessary for sound localization. the mechanisms that shape bicoordinate spatial representation in the auditory cortex remain unclear. here, we addressed this issue by quantifying spatial receptive fields (srfs) in two functionally distinct cortical regions in the pallid bat. the pallid bat uses echolocation for obstacle avoidance and listens to prey-generated noise to localize prey. its cortex contains two segregated regions of response selectivity that serve echolocation ...201526658863
development of echolocation calls and neural selectivity for echolocation calls in the pallid bat.studies of birdsongs and neural selectivity for songs have provided important insights into principles of concurrent behavioral and auditory system development. relatively little is known about mammalian auditory system development in terms of vocalizations or other behaviorally relevant sounds. this review suggests echolocating bats are suitable mammalian model systems to understand development of auditory behaviors. the simplicity of echolocation calls with known behavioral relevance and stron ...201525142131
detecting and quantifying topography in neural maps.topographic maps are an often-encountered feature in the brains of many species, yet there are no standard, objective procedures for quantifying topography. topographic maps are typically identified and described subjectively, but in cases where the scale of the map is close to the resolution limit of the measurement technique, identifying the presence of a topographic map can be a challenging subjective task. in such cases, an objective topography detection test would be advantageous. to addres ...201424505279
effects of sound intensity on temporal properties of inhibition in the pallid bat auditory cortex.auditory neurons in bats that use frequency modulated (fm) sweeps for echolocation are selective for the behaviorally-relevant rates and direction of frequency change. such selectivity arises through spectrotemporal interactions between excitatory and inhibitory components of the receptive field. in the pallid bat auditory system, the relationship between fm sweep direction/rate selectivity and spectral and temporal properties of sideband inhibition have been characterized. of note is the tempor ...201323761762
multiple mechanisms shape fm sweep rate selectivity: complementary or redundant?auditory neurons in the inferior colliculus (ic) of the pallid bat have highly rate selective responses to downward frequency modulated (fm) sweeps attributable to the spectrotemporal pattern of their echolocation call (a brief fm pulse). several mechanisms are known to shape fm rate selectivity within the pallid bat ic. here we explore how two mechanisms, stimulus duration and high-frequency inhibition (hfi), can interact to shape fm rate selectivity within the same neuron. results from extrace ...201222912604
mechanisms underlying azimuth selectivity in the auditory cortex of the pallid bat.this study focused on mechanisms underlying azimuth selectivity in the primary auditory cortex (a1) of pallid bats. the pallid bat listens to prey-generated noise (5-35 khz) to localize and hunt terrestrial prey. the region of a1 tuned between 5 and 35 khz consists of two clusters of neurons distinguished by interaural intensity difference (iid) selectivity: binaurally inhibited (ei) and peaked. the first aim of this study was to use sequential dichotic/free-field stimulation to test the hypothe ...201222641192
mechanisms underlying intensity-dependent changes in cortical selectivity for frequency-modulated sweeps.frequency-modulated (fm) sweeps are common components of species-specific vocalizations. the intensity of fm sweeps can cover a wide range in the natural environment, but whether intensity affects neural selectivity for fm sweeps is unclear. bats, such as the pallid bat, which use fm sweeps for echolocation, are suited to address this issue, because the intensity of echoes will vary with target distance. in this study, fm sweep rate selectivity of pallid bat auditory cortex neurons was measured ...201222279192
systematic representation of sound locations in the primary auditory cortex.the primary auditory cortex (a1) is involved in sound localization. a consistent observation in a1 is a clustered representation of binaural properties, but how spatial tuning varies within binaural clusters is unknown. here, this issue was addressed in a1 of the pallid bat, a species that relies on passive hearing (as opposed to echolocation) to localize prey. evidence is presented for systematic representations of sound azimuth within two binaural clusters in the pallid bat a1: the binaural in ...201121957247
differential roles of gabaergic and glycinergic input on fm selectivity in the inferior colliculus of the pallid bat.multiple mechanisms have been shown to shape frequency-modulated (fm) selectivity within the central nucleus of the inferior colliculus (ic) in the pallid bat. in this study we focus on the mechanisms associated with sideband inhibition. the relative arrival time of inhibition compared with excitation can be used to predict fm responses as measured with a two-tone inhibition paradigm. an early-arriving low-frequency inhibition (lfi) prevents responses to upward sweeps and thus shapes direction s ...201121775712
development of parallel auditory thalamocortical pathways for two different behaviors.auditory thalamocortical connections are organized as parallel pathways that originate in different divisions of the medial geniculate body (mgb). these pathways may be involved in different functions. surprisingly little is known about the development of these connections. here we review studies of the organization and development of auditory thalamocortical pathways in the pallid bat. the pallid bat depends primarily on passive hearing of prey-generated noise for localizing prey, while reservi ...201020941327
experience-dependent development of vocalization selectivity in the auditory cortex.vocalization-selective neurons are present in the auditory systems of several vertebrate groups. vocalization selectivity is influenced by developmental experience, but the underlying mechanisms are only beginning to be understood. evidence is presented in this review for the hypothesis that plasticity of timing and strength of inhibition is a mechanism for plasticity of vocalization selectivity. the pallid bat echolocates using downward frequency modulated (fm) sweeps. nearly 70% of neurons wit ...201020815478
facilitatory mechanisms shape selectivity for the rate and direction of fm sweeps in the inferior colliculus of the pallid bat.the inferior colliculus (ic) of the pallid bat has a large percentage of neurons that respond selectively to the rate and direction of the bat's echolocation pulse, a downward fm sweep. three underlying mechanisms have been previously described. here we describe a fourth mechanism, facilitation, that shapes selectivity for both sweep rate and direction. the neurons studied are termed fm specialists, because they do not respond to tones. most were selective for the downward sweep direction, and t ...201020631213
multiple mechanisms shape selectivity for fm sweep rate and direction in the pallid bat inferior colliculus and auditory cortex.the inferior colliculus and auditory cortex of the pallid bat contain a large percentage of neurons that are highly selective for the direction and rate of the downward frequency modulated (fm) sweep of the bat's echolocation pulse. approximately 25% of neurons tuned to the echolocation pulse respond exclusively to downward fm sweeps. this review focuses on the finding that this selectivity is generated by multiple mechanisms that may act alone or in concert. in the inferior colliculus, selectiv ...201120596868
gaba shapes a systematic map of binaural sensitivity in the auditory cortex.a consistent organizational feature of auditory cortex is a clustered representation of binaural properties. here we address two questions. what is the intrinsic organization of binaural clusters and to what extent does intracortical processing contribute to binaural representation. we address these issues in the auditory cortex of the pallid bat. the pallid bat listens to prey-generated noise transients to localize and hunt terrestrial prey. as in other species studied, binaural clusters are pr ...201020484524
gaba shapes selectivity for the rate and direction of frequency-modulated sweeps in the auditory the pallid bat auditory cortex and inferior colliculus (ic), the majority of neurons tuned in the echolocation range is selective for the direction and rate of frequency-modulated (fm) sweeps used in echolocation. such selectivity is shaped mainly by spectrotemporal asymmetries in sideband inhibition. an early-arriving, low-frequency inhibition (lfi) shapes direction selectivity. a delayed, high-frequency inhibition (hfi) shapes rate selectivity for downward sweeps. using iontophoretic blocka ...200919553486
venomotion modulates lymphatic pumping in the bat skin, it is believed that lymph must be pumped by intrinsic contraction of lymphatic muscle, since investigators have not considered that cyclical dilation of venules could compress adjacent lymphatic microvessels. because lymphatic vessels are sensitive to stretch, we hypothesized that venomotion not only can cause extrinsic pumping of lymph in nearby lymphatic vessels, but also can stimulate intrinsic contractions. bat wing venules have pronounced venomotion and are in close proximity to ly ...200919329767
facilitatory mechanisms underlying selectivity for the direction and rate of frequency modulated sweeps in the auditory cortex.neurons selective for frequency modulated (fm) sweeps are common in auditory systems across different vertebrate groups and may underlie representation of species-specific vocalizations. studies on mechanisms of fm sweep selectivity have primarily focused on sideband inhibition. here, we present the first evidence for facilitatory mechanisms of fm sweep selectivity. facilitatory interactions were found in 46 of 264 (17%) neurons tuned in the echolocation range (25-60 khz) in the auditory cortex ...200818815265
development of functional organization of the pallid bat auditory cortex.the primary auditory cortex is characterized by a tonotopic map and a clustered organization of binaural properties. the factors involved in the development of overlain representation of these two properties are unclear. we addressed this issue in the auditory cortex of the pallid bat. the adult pallid bat cortex contains a systematic relationship between best frequency (bf) and binaural properties. most neurons with bf<30 khz are binaurally inhibited (eo/i), while most neurons with bf>30 khz ar ...200717321705
development of inhibitory mechanisms underlying selectivity for the rate and direction of frequency-modulated sweeps in the auditory cortex.although it is known that neural selectivity for species-specific vocalizations changes during development, the mechanisms underlying such changes are not known. this study followed the development of mechanisms underlying selectivity for the direction and rate of frequency-modulated (fm) sweeps in the auditory cortex of the pallid bat, a species that uses downward fm sweeps to echolocate. in the adult cortex, direction and rate selectivity arise as a result of different spectral and temporal pr ...200717301184
local heat produces a shear-mediated biphasic response in the thermoregulatory microcirculation of the pallid bat wing.investigators report that local heat causes an increase in skin blood flow consisting of two phases. the first is solely sensory neural, and the second is nitric oxide mediated. we hypothesize that mechanisms behind these two phases are causally linked by shear stress. because microvascular blood flow, endothelial shear stress, and vessel diameters cannot be measured in humans, bat wing arterioles (26.6 +/- 0.3, 42.0 +/- 0.4, and 58.7 +/- 2.2 microm) were visualized noninvasively on a transparen ...200616675627
inhibition has little effect on response latencies in the inferior colliculus.the inferior colliculi of all mammals are characterized by a wide range of first-spike response latencies that can greatly exceed the minimum time required for the transmission of input through the lower brainstem. the mechanisms that account for long response latencies of up to 50 ms are unclear, but one hypothesis is that an early inhibition plays a role in shaping latency. to test this hypothesis, response latencies were measured in the inferior colliculi of the pallid and mustached bats befo ...200312183767
functional organization of the pallid bat auditory cortex: emphasis on binaural organization.this report maps the organization of the primary auditory cortex of the pallid bat in terms of frequency tuning, selectivity for behaviorally relevant sounds, and interaural intensity difference (iid) sensitivity. the pallid bat is unusual in that it localizes terrestrial prey by passively listening to prey-generated noise transients (1-20 khz), while reserving high-frequency (<30 khz) echolocation for obstacle avoidance. the functional organization of its auditory cortex reflects the need for s ...200211784731
a systematic representation of interaural intensity differences in the auditory cortex of the pallid bat.the current model of cortical processing of auditory spatial information is based on an orthogonal representation of frequency and binaural response properties, but how this arrangement leads to representation of space in the auditory cortex is unclear. this study describes the first evidence of a cortical substrate for the systematic representation of space in a region of primary auditory cortex of the pallid bat that subserves passive sound localization. the organizational feature of this regi ...200011006966
neuronal sensitivity to interaural time differences in the sound envelope in the auditory cortex of the pallid bat.interaural time differences in the envelope of a sound (envelope itds) can potentially provide spatial information at high frequencies where interaural phase differences (ipds) are not available. interaural intensity differences (iids) also provide important spatial information at high frequencies. both iids and envelope itds can influence spatial perception at high frequencies, but behavioral and physiological studies suggest that iids dominate perception. this study examines envelope itd sensi ...200010771183
sound duration selectivity in the pallid bat inferior colliculus.neurons selective for sound duration have been reported in the auditory midbrain and cortex of several specialized vertebrate species that process behaviorally relevant signals of stereotypic duration. this study examines duration selectivity in the inferior colliculus (ic) of the pallid bat to determine if this selectivity is limited to regions that serve echolocation, or if it extends to low-frequency regions that serve passive listening. it also focuses on the temporal response properties of ...199910545641
single cortical neurons serve both echolocation and passive sound localization.the pallid bat uses passive listening at low frequencies to detect and locate terrestrial prey and reserves its high-frequency echolocation for general orientation. while hunting, this bat must attend to both streams of information. these streams are processed through two parallel, functionally specialized pathways that are segregated at the level of the inferior colliculus. this report describes functionally bimodal neurons in auditory cortex that receive converging input from these two pathway ...199910085371
role of gaba in shaping frequency tuning and creating fm sweep selectivity in the inferior colliculus.1. we examined the role of gamma-aminobutyric acid (gaba)-mediated inhibition in shaping excitatory tuning curves and creating selectivity for frequency-modulated (fm) sweeps in 29 neurons in the central nucleus of the inferior colliculus (icc) of the pallid bat, with the use of single-unit recording coupled with the iontophoretic application of bicuculline methiodide (bic), an antagonist of gabaa receptors. 2. bic increased response magnitude 2 to 6 times over pretreatment levels in > 80% of ne ...19968871220
response selectivity for multiple dimensions of frequency sweeps in the pallid bat inferior colliculus.1. while hunting, the pallid bat uses passive sound localization at low frequencies to find terrestrial prey, and echolocation for general orientation. it must therefore process two different types of acoustic input at the same time. the pallid bat's echolocation pulse is a downward frequency-modulated (fm) sweep from 60 to 30 khz. this study examined the response selectivity of single neurons in the pallid bat's central nucleus of the inferior colliculus (icc) for fm sweeps, comparing the respo ...19947807196
spontaneous contractions of isolated bat wing venules are inhibited by luminal flow.the hypothesis that spontaneous contractions of bat wing venules could be modulated by luminal flow was tested. single venules (114 +/- 5 microns diam) from the wings of anesthetized pallid bats were dissected, cannulated, and pressurized in vitro. a dual reservoir system was used to independently control luminal pressure and flow. in the absence of flow, and with pressure set to 10 cmh2o, all venules contracted spontaneously at rates between 20 and 40 cycles/min. pressure elevation over the ran ...19938476096
passive sound localization of prey by the pallid bat (antrozous p. pallidus).the pallid bat (antrozous p. pallidus) uses passive sound localization to capture terrestrial prey. this study of captive pallid bats examined the roles of echolocation and passive sound localization in prey capture, and focused on their spectral requirements for accurate passive sound localization. crickets were used as prey throughout these studies. all tests were conducted in dim, red light in an effort to preclude the use of vision. hunting performance did not differ significantly in red lig ...19938441123
circannual cycles of body mass food intake and reproductive condition in male pallid bats.gonadectomy did not eliminate circannual cycles of body mass and food intake in male pallid bats maintained for up to 30 months in short or long photoperiods at a constant temperature of 23 +/- 2 degrees c. generation and expression of circannual rhythms is independent of the annual testicular cycle. initial peak body and testicular masses were recorded within one month of each other but the peak in food intake occurred approximately eight months after animals attained peaks in body mass. increa ...19863823185
interspecific comparison of subcutaneous tissue fluid pressure in the bat wing.tissue fluid pressures were recorded from subcutaneous tissues of three bat species by means of an improved servo-micropipet pressure recording system. experimental animals were restrained but unanesthetized during the procedure by methods which avoided vascular occlusion. tissue fluid pressures averaged +0.46 +/- 2.08 mm hg (n = 12) in the mexican free-tailed bat, +0.21 +/- 0.63 mm hg (n = 14) in the pallid bat, and -0.31 +/- 1.01 mm hg (n = 12) in the little brown bat. none of the average valu ...19854021839
circannual rhythms of body weight in pallid bats.body weights of pallid bats collected in the field were substantially greater during october and december than between april and september. when maintained in the laboratory under constant conditions of photoperiod and temperature, bats manifested circannual rhythms in body weight. these endogenous cycles were observed in adult and juvenile individuals of both sexes and in bats housed in long or short photoperiods (14 or 10 h of light/day). the period of the cycle averaged 10 mo. photoperiod inf ...19846742175
melatonin influences the reproductive physiology of male pallid male pallid bats collected in july were maintained in photoperiods that provided 14 or 10 h of light/day (long or short days) and implanted subcutaneously with empty or melatonin-filled silastic capsules. by early september, long-day bats treated with melatonin had smaller testes, larger accessory gland complexes and were more likely to have epididymal sperm than long-day bats which received empty capsules. in addition, in september, melatonin-treated animals weighed more than untreated an ...19846704467
bile duct adenocarcinoma in a pallid bat (antrozeous pallidus). 19826290689
binaural response properties and sensitivity to interaural difference of neurons in the auditory cortex of the big brown bat, eptesicus fuscus.this study examines binaural response properties and sensitivity to interaural level difference of single neurons in the primary auditory cortex (ac) of the big brown bat, eptesicus fuscus under earphone stimulation conditions. contralateral sound stimulation always evoked response from all 306 ac neurons recorded but ipsilateral sound stimulation either excited, inhibited or did not affect their responses. high best frequency (bf) neurons typically had high minimum threshold (mt) and low bf neu ...202031785358
mesquite bugs, other insects, and a bat in the diet of pallid bats in southeastern arizona.the pallid bat (antrozous pallidus) is a species of western north america, inhabiting ecoregions ranging from desert to oak and pine forest. they are primarily insectivorous predators on large arthropods that occasionally take small vertebrate prey, and are at least seasonally omnivorous in certain parts of their geographic range where they take nectar from cactus flowers and eat cactus fruit pulp and seeds. until recently, mesquite bugs were primarily tropical-subtropical inhabitants of mexico ...201830533321
accurate sound localization behavior in a gleaning bat, antrozous pallidus.acute auditory processing in bats is typically associated with echolocation. a subset of bats, called gleaners, listens to prey-generated noise to hunt surface-dwelling prey. gleaners depend less on echolocation to hunt and, therefore, accurate localization of prey-generated noise is necessary for foraging success. here we studied azimuth sound localization behavior in the pallid bat, a gleaning bat in which spatial encoding has been studied extensively. we tested pallid bats on a relatively dif ...201830194319
adaptations for substrate gleaning in bats: the pallid bat as a case study.substrate gleaning is a foraging strategy in which bats use a mixture of echolocation, prey-generated sounds, and vision to localize and hunt surface-dwelling prey. many substrate-gleaning species depend primarily on prey-generated noise to hunt. use of echolocation is limited to general orientation and obstacle avoidance. this foraging strategy involves a different set of selective pressures on morphology, behavior, and auditory system organization of bats compared to the use of echolocation fo ...201829874652
topography of sound level representation in the fm sweep selective region of the pallid bat auditory cortex.sound level processing is a fundamental function of the auditory system. to determine how the cortex represents sound level, it is important to quantify how changes in level alter the spatiotemporal structure of cortical ensemble activity. this is particularly true for echolocating bats that have control over, and often rapidly adjust, call level to actively change echo level. to understand how cortical activity may change with sound level, here we mapped response rate and latency changes with s ...201829853324
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