Publications

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transmission of a strain of rabies virus to the large brown bat (eptesicus fuscus) and to the cave bat (myotis lucifugus). 195114849156
viability of the lansing strain of poliomyelitis virus in the bat (eptesicus fuscus). 195214949015
effect of pseudorabies virus (aujeszky strain) in the large brown bat (eptesicus fuscus). 195313050899
a trypanosome from the big brown bat, eptesicus fuscus fuscus (beauvois), in minnesota. 195513272117
brown fat: thermogenic effect during arousal from hibernation in the bat.in the bat eptesicus fuscus the temperature of brown fat exceeded that of other tissues by about 3 degrees c during the late stages of arousal from hibernation. heat production seems to be a major function of brown fat in the hibernating mammal.196313989313
bats: sensitivity to ddt.big brown bats, eptesicus fuscus, were fed single doses of varying amounts of ddt in corn oil injected into meal worms. all the doses of ddt fed to the bats, 40 milligrams or more per kilogram of body weight, were lethal. within a few hours to 13 days after being dosed, the animals developed convulsions; some bats survived up to 3 days after the oniset of the symptoms of poisoning. bats appear to be far more sensitive to ddt than any other mammal yet tested.196414199722
bat rabies in ontario.rabies has been diagnosed for the first time in the bat population of ontario. in the course of a study involving 72 bats from 24 counties of the province, five big brown bats (e. fuscus) were found to be infected with rabies through the mouse inoculation test. at the present time, it does not look as if bats have been connected with the epizootic of sylvatic rabies in ontario.la rage est apparue pour la première fois chez les chauves-souris en ontario. au cours d'une étude qui a porté sur 72 de ...196417649490
hearing sensitivity in bats.absolute hearing thresholds for two bats were determined by an operant conditioning technique. pure tones rangingfrom 2.5 to 100 kilocycles per second were perceived by a single eptesicus fuscus. its maximum sensitivity was on the order of 68 decibles below 1 dyne per square centimeter and occurred at 20 kc/ sec. maximum sensitivity for a single myotis lucifugus was about 64 db below 1 dyne/ cm2 and occurred at 40 kc/ sec. the myotis clearly heard a tone of120 kc/ sec but gave no evidence of hea ...19655852976
parasites from the big brown bat, eptesicus fuscus (beauvois), in western maryland (acarina and siphonaptera). 196514280484
use of big brown bats (eptesicus fuscus) in biomedical research. 19664225475
studies of arthropod-borne virus infections in chiroptera. iv. the immune response of the big brown bat (eptesicus f. fuscus) maintained at various environmental temperatures to experimental japanese b encephalitis virus infection. 19664287168
hearing and cochlear microphonic potentials in the bat eptesicus fuscus. 19676035688
studies of arthropod-borne virus infections in chiroptera. v. characteristics of lines of japanese b encephalitis virus developed by serial passage in big brown bats (eptesicus f. fuscus) maintained at different environmental temperatures. 19695764191
bat rabies in canada 1963-1967.six hundred and twenty-eight insectivorous bats originating from seven provinces were submitted to this institute for rabies diagnosis between august 1, 1963 and december 31, 1967. brain tissue was examined by the fluorescent antibody technique and the mouse infectivity test was carried out with brain, salivary gland, interscapular adipose tissue and kidney samples. rabies virus was detected in 44 bats, 29 of which were from ontario, 12 from british columbia and three from manitoba. most of the ...19694242773
prolonged incubation period of rabies in a naturally infected insectivorous bat, eptesicus fuscus (beauvois). 19705424435
fine structure of the pancreatic islet cells of normal and alloxan treated bats (eptesicus fuscus). 19704905599
fluctuations in the preoptic-anterior hypothalamic temperature in the bat, eptesicus fuscus. 19714400037
echolocation in bats: signal processing of echoes for target range.echolocating bats eptesicus fuscus and phyllostomus hastatus can discriminate between the nearer and farther of two targets. their errors in discrimination are predicted accurately by the autocorrelation functions of their sonar cries. these bats behave as though they have an ideal sonar system which cross correlates the transmitted cry with the returning echo to extract targetrange information.19715541661
echolocation: discrimination of targets by the bat, eptesicus fuscus. 19715548872
transit time of food through the digestive tract of the bat, eptesicus fuscus. 19715147598
metabolized energy of the big brown bat eptesicus fuscus (chiroptera). 19734145443
populations and distribution of steatonyssus occidentalis (ewing) (acarina: macronyssidae) infesting the big brown bat, eptesicus fuscus (chiroptera: vespertilionidae). 19734779927
sequential changes in regional distribution of blood in eptesicus fuscus (big brown bat) during arousal from hibernation. 19734779820
response at fifteen weeks of the big brown bat (eptesicus fuscus) to intraperitoneal injections of n-2-acetylaminofluorene. 19744472289
reproduction, growth, and mortality of the vespertilionid bat, eptesicus fuscus, in kansas. 19744819591
brightness discrimination thresholds in the bat, eptesicus fuscus. 19744462692
differential in rectal and chest muscle temperature during arousal in eptesicus fuscus and myotis sodalis (chiroptera: vespertilionidae). 19744156236
comparison of regional blood distribution in eptesicus fuscus (big brown bat) during torpor (summer), hibernation (winter), and arousal. 19751116073
canine tooth wear in captive big brown bats (eptesicus fuscus). 19761003049
organochlorine residues in three bat species from four localities in maryland and west virginia, 1973.in 1973, 119 bats of three species were collected from four localities in maryland and west virginia. the collection included 43 big brown bats (eptesicus fuscus), 43 little brown brown bats (myotis lucifugus), and 33 eastern pipistrelles (pipistrellus subflavus). the bats were collected from round top mountain, washington co., md.; trout cave, pendleton co., w. va.; montpelier barn, prince georges co., md. residues of sigmaddt were highest in carcasses of bats from round top mountain, which is ...1976826874
[histoplasma capsulatum: isolation from bats in cuba].a mycologic-serologic study of 169 bats of species artibeus jamaicensis parvipos, brachyphyllanana, eptesicus fuscus dutertreus, tadarida brasiliensis muscula and mormoops blainvillei which were catched in a cave of havana province is presented. histoplasma capsulatum were isolated from the lungs, liver and spleen, in four out of the five species studied. all species were serologically negative.1976802802
sodium pentobarbital induced alterations in regional distribution of blood in peromyscus maniculatus (deer mouse) and eptesicus fuscus (big brown bat). 1977606346
naturally occurring rabies virus and neutralizing antibody in two species of insectivorous bats of new york state.seven colonies of eptesicus fuscus , the big brown bat, and five colonies of myotis lucifugus , the little brown bat, in new york state were sampled for rabies virus and virus-neutralizing antibody. eight of 278 e. fuscus were found to have virus, while 18 of 187 had antibody titers of ≥1:8. one of 333 m. lucifugus yielded virus, while three of 127 had antibody. these data demonstrate the presence of rabies virus as well as immunity to rabies in some insectivorous bats of new york state. evaluat ...197724228955
echo detection and target-ranging neurons in the auditory system of the bat eptesicus fuscus.some of the neurons in the nucleus intercollicularis and auditory cortex of the echolocating bat eptesicus fuscus respond selectively to sonar echoes occurring with specific echo delays or pulse-echo intervals. they do not respond for a wide range of other types of sounds or for sonar echoes at longer or shorter pulse-echo intervals; they may, therefore, be specialized for detection and ranging of sonar targets.1978705350
perception of echo phase information in bat sonar.echolocating bats (eptesicus fuscus) can detect changes as small as 500 nanoseconds in the arrival time of sonar echoes when these changes appear as jitter or alternations in arrival time from one echo to the next. the psychophysical function relating the bat's performance to the magnitude of the jitter corresponds to the half-wave rectified cross-correlation function between the emitted sonar signals and the echoes. the bat perceives the phase or period structure of the sounds, which cover the ...1979451543
ultrastructure of the atrioventricular node of the big brown bat, eptesicus fucus.this investigation describes the ultrastructure of the atrioventricular node of eptesicus fuscus. two conducting cells types (nodal and transitional) are indentified which differ in location, myofibrillar content, and types of intercellular junctions. centrally located nodal cells display variable staining intensity and contain disorganized myofibrils which rarely form sarcomeres. desmosomes and nexus-like junctions connect the nodal cells. transitional cells, situated peripherally, exhibit dist ...1979532545
electrical response of bat retina to spectral stimulation: comparison of four microhiropteran species.electrical responses of the retinas of 4 species of microchiropteran bats stimulated by spectrally restricted light flashes were found to diverge systematically from the rhodopsin absorption spectrum. the divergence was progressively greater across the 4 species. the results appeared explainable by assuming a second photoreceptor class and photopigment which was present in progressively greater numbers in the retinas of eptesicus fuscus, desmodus rotundus, artibeus jamaicensis and carollia persp ...1979488274
neurons in the cerebellum of echolocating bats respond to acoustic signals.single neurons responding to auditory stimuli (40 msec duration, 0.5 msec rise-decay time) could be isolated from rather large areas of the cerebellar vermis and hemispheres of an echolocating bat, eptesicus fuscus. these neurons had latencies between 4 and 13 msec and best frequencies between 22 and 77 khz. the q10-db values of their tuning curves were between 1.4 and 16.6. when acoustic stimuli were delivered though the earphones, tuning curves measured from each ear alone were nearly identica ...19807397541
characteristics of bat rabies in alberta.rabies in bats was monitored in alberta from 1971 to 1978 big brown bats replaced silver-haired bats as the species most frequently reported rabid during these years. rabies infection was comparatively high among little brown bats in central alberta in 1973 and has subsequently declined. only one rabid little brown bat was discovered in southern alberta which is populated by a different subspecies. outbreaks of rabies in little brown and big brown bat colonies tended to be brief events. observat ...19807397600
a mathematical model describing the effect of temperature and substrate concentration on the activities of m4 and h4 lactate dehydrogenase from the big brown bat (eptesicus fuscus). 19817325684
bats in the belfry: an outbreak of histoplasmosis.the belfry and attic of a 100-year-old school building located in central illinois were infested with a colony of big brown bats (eptesicus fuscus). during the week of april 14, 1980, four workers disturbed the piles of bat droppings in the attic, causing dust to become airborne. seven to 10 days later, all four workers developed symptoms and chest x-ray findings compatible with acute pulmonary histoplasmosis. their sera had complement fixation (cf) titers of greater than or equal to 1:32 with f ...19827137434
echolocation in bats: the external ear and perception of the vertical positions of targets.echolocating bats (eptesicus fuscus) can perceive changes of as little as 3 degrees of arc in the vertical angles separating pairs of horizontal rods. this acuity depends upon modification of sounds entering the external ear canal by the structures of the external ear. deflection of the tragus degrades the acuity of vertical-angle perception from 3 degrees to about 12 degrees to 14 degrees. the pinna-tragus structure produces a strong secondary echo of sounds entering the external ear canal, and ...19827123247
concentrations of lactate and pyruvate and temperature effects on lactate dehydrogenase activity in the tissues of the big brown bat (eptesicus fuscus) during arousal from hibernation.1. the rectal temperatures, steady state concentrations of lactate and pyruvate, and the ldh isoenzyme composition in the heart, liver, and pectoral muscle of hibernating and arousing eptesicus fuscus were measured. 2. bat rectal temperature increased from 8.86 to 33.1 degrees c during arousal. 3. during arousal, steady state concentrations of pyruvate and lactate increased significantly in the tissues, however they remained generally below the level necessary to saturate ldh at the respective t ...19827151414
neurons in the superior colliculus of echo-locating bats respond to ultrasonic signals.using conventional electrophysiological techniques, we demonstrate that neurons in the superior colliculus of the big brown bat (eptesicus fuscus) respond to ultrasonic signals. most response properties of these neurons are very similar to neurons of the inferior colliculus in the same bat.19836626974
unmasking in neurons of the inferior colliculus of eptesicus fuscus with binaural stimulation.171 single inferior colliculus neurons displaying basic auditory properties similar to those described previously were sampled, and 118 of those were tested to determine whether monaurally masked responses (band passed noise of +/- 5 khz around the best frequency of the pure tone) could be recovered if the masking noise was presented binaurally. 26% of the units tested showed such an improvement in signal detection, i.e. what is called masking level difference (mld) by psychoacousticians. signal ...19836874604
a comparison of milk composition in myotis lucifugus and eptesicus fuscus (chiroptera: vespertilionidae).milk composition in two species of insectivorous bats (myotis lucifugus and eptesicus fuscus) was determined. no significant differences in fat, lactose, protein, or energy content were evident during the lactation period for m. lucifugus. the percentage of fat, lactose, and protein averaged 13.5, 3.3, 7.4, respectively, for m. lucifugus, and 16.4, 2.5, 6.2, respectively, for e. fuscus. energy content of milk averaged 7.32 kj/g for m. lucifugus and 8.37 kj/g for e. fuscus. the percentage of lact ...19836830940
biochemical and morphometric studies of heart, liver and skeletal muscle from the hibernating, arousing and aroused big brown bat, eptesicus fuscus.heart, liver, pectoralis major, and plasma of hibernating, arousing and aroused bats were studied. the activities of four mitochondrial enzymes and three morphometric parameters of mitochondria did not change in the heart. mitochondrial enzyme activities in the liver and pectoralis major did not change. lactate dehydrogenase activity and isoenzyme content in heart, liver and pectoralis major did not change. heart lipid content determined morphometrically decreased transiently after 30 min arousa ...19836641165
maseria vespertilionis n.g., n.sp. (dorylaimina : muspiceidae), a nematode from nearctic bats (vespertilionidae).maseria vespertilionis n. g., n. sp. (dorylaimina : muspiceidae) is described from nearctic bats (vespertilionidae). in addition to the type host, eptesicus fuscus (p. de beauvois), in oregon, m. vespertilionis was recorded from myotis volans (allen) in oregon, and from m. lucifugus (le conte) in oregon and alaska. the nematode was found only in subcutaneous tissues near the plantar surface of the rear feet of the host. the genus maseria is distinguished from other genera in muspiceidae by vario ...19836638790
reservoir of st. louis encephalitis virus in ohio bats.inoculation of the big brown bat (eptesicus fuscus) with a small dose of a st. louis encephalitis (sle) virus strain isolated in ohio indicated that the big brown bat was susceptible to infection. the virus was maintained in the bats through hibernation (70 days), and the bats developed a viremia within 4 days of arousal from hibernation (105 days after inoculation). a field survey of 390 big brown bats and little brown bats (myotis lucifugus) conducted in 5 regions of ohio during 1979 to 1981 r ...19836638648
auditory space representation in the superior colliculus of the big brown bat, eptesicus fuscus.the auditory response areas of 123 superior collicular (sc) units of eptesicus fuscus were studied under free-field acoustic stimulus conditions. a stimulus was delivered from a loudspeaker placed 14 cm in front of a bat. the best frequency of a unit was determined by changing the stimulus frequency until the minimum threshold was measured. a best frequency stimulus was then delivered as the loud-speaker was moved across the auditory space to determine the response center of the auditory respons ...19846498487
preference of a revolving target to a stationary one by the big brown bat, eptesicus fuscus.utilizing a three-ramp platform, we studied the detection of a revolving and a stationary target in the presence of background clutter by trained eptesicus fuscus. during the test, the mean amplitude of echo from either target was always larger than that of the background echoes at the bat-to-target distance of 30, 70 and 100 cm. the amplitude of the echo reflected back from a revolving target was modulated between a maximum and a minimum value. an electric motor was used to revolve a target. th ...19846571589
pinna orientation determines the maximal directional sensitivity of bat auditory neurons.the auditory response areas of 192 inferior collicular neurons (ic) of eptesicus fuscus were studied under free field acoustic stimulation. the boundary of the auditory response area of a neuron expands with stimulus intensity (fig. 1). however, there is a response center within each neuron's response area at which the neuron has the maximal sensitivity. all response centers of the 192 neurons are located within a limited space of the bat's contralateral auditory space. the position of the respo ...19846733486
automatic gain control in the bat's sonar receiver and the neuroethology of echolocation.the sensitivity of the echolocating bat, eptesicus fuscus, to sonar echoes at different time delays after sonar emissions was measured in a two-choice echo detection experiment. since echo delay is perceptually equivalent to target range, the experiment effectively measured sensitivity to targets at different ranges. the bat's threshold for detecting sonar echoes at a short delay of only 1.0 msec after emissions (corresponding to a range of 17 cm) was 36 db spl (peak to peak), but the threshold ...19846502201
sonar tracking of horizontally moving targets by the big brown bat eptesicus fuscus.when following a moving target, echolocating bats (eptesicus fuscus) keep their heads aimed at the target's position. this tracking behavior seems not to involve predicting the target's trajectory, but is achieved by the bat's pointing its head at the target's last known position. the bat obtains frequent position updates by emitting sonar signals at a high rate. after the lag between head and target positions and the nonunity tracking gain were corrected for, bats' tracking accuracy in the hori ...19854001947
bat rabies in alberta 1979-1982.the infection rate among eight species of bats submitted for rabies diagnosis in alberta during 1979-82 was 4.6%. prevalence of rabies was greatest (24%) for hoary bats lasiurus cinereus, while the big brown bat eptesicus fuscus was the species in which rabies was most commonly diagnosed, and the species submitted most frequently for rabies diagnosis was the little brown bat myotis lucifugus. the rabies infection rate among male hoary bats was significantly greater than in either sex of all othe ...198517422507
retinofugal projections of the big brown bat, eptesicus fuscus and the neotropical fruit bat, artibeus jamaicensis.retinal connections were studied in eptesicus fuscus and artibeus jamaicensis using anterograde axonal degeneration and autoradiographic techniques following unilateral enucleations and uniocular injections of radioactive amino acids. although each retina projected bilaterally to the brainstem, the number of silver grains in the emulsion of autoradiographs indicated that nearly all fibers in the optic nerve entered the contralateral optic tract. ipsilaterally, a major portion of the projection e ...19852983524
major antigenic groups of rabies virus in canada determined by anti-nucleocapsid monoclonal antibodies.a total of 123 rabies virus isolates from various geographical areas in canada were characterized by a panel of 43 anti-nucleocapsid monoclonal antibodies. four major antigenic groups are found in terrestrial mammals: "canadian arctic" from ontario, quebec and the northwest territories; "south-eastern georgian bay" from ontario; "south mid-central skunk" from alberta, saskatchewan and manitoba; and "brook's, alberta skunk" from a restricted area in alberta. bat isolates can be divided into 4 maj ...19863769442
rabies in insectivorous bats of western canada, 1979 to 1983.a total of 1,745, 362, and 536 bats collected in alberta, british columbia, and saskatchewan, respectively, was tested for rabies virus between 1979 and 1983. only one (0.1%) of 769 bats collected at random from buildings was infected with rabies virus in contrast to 95 (5%) of 1,874 symptomatic, rabies-suspect bats submitted for testing. the pattern of infection in the rabies-suspect bats was similar in alberta and saskatchewan, but differed in british columbia. rabies was diagnosed in four spe ...19863735577
experimentally induced rabies in four cats inoculated with a rabies virus isolated from a bat.four cats were inoculated im with rabies virus isolated from the salivary gland of a naturally infected big brown bat (eptesicus fuscus). the 4 cats developed clinical signs of rabies after a median incubation period of 42 days. the median duration of clinical illness was 5 days. results of fluorescent antibody evaluation, mouse inoculation, and tissue culture isolation indicated large differences in virus concentrations in various areas of the cns of individual cats. these differences also were ...19863516030
connectional basis for frequency representation in the nuclei of the lateral lemniscus of the bat eptesicus fuscus.to study the role of the lateral lemniscus as a link in the ascending auditory pathway, injections of neuronal tracers were placed in the anteroventral cochlear nucleus (avcn) and in the inferior colliculus of the bat eptesicus fuscus. to correlate the anatomical results with tonotopic organization, the characteristic frequency of cells at each injection site was determined electrophysiologically. pathways from avcn diverge to 3 major targets in the lateral lemniscus, the intermediate nucleus an ...19863020188
accuracy of distance measurement in the bat eptesicus fuscus: theoretical aspects and computer simulations.behavioral experiments of simmons [j. acoust. soc. am. 54, 157-173 (1973) and science 204, 1336-1338 (1979)] on the ranging accuracy in the bat eptesicus fuscus have led to far-reaching postulates on the existence of optimal and phase-conserving processing mechanisms in the bat. in this paper, the results of computer simulations of these experiments are presented. two receiver types are investigated: the fully coherent cross-correlation receiver and the cross-correlation receiver with envelope p ...19863950192
phase evaluation in hypothetical receivers simulating ranging in bats.echo delay discrimination by the bat eptesicus fuscus had been investigated in an experiment with simulated targets jittering in range (simmons 1979). the dip in the resulting psychometric curve was used by simmons to suggest the neuronal implementation of a coherent cross-correlation receiver in the auditory system of bats. by computer simulation it is shown here that the dip may be even more pronounced and less susceptible to noise with alternative receiver configurations which not necessarily ...19863755621
auditory space representation in the inferior colliculus of the fm bat, eptesicus fuscus.the auditory spatial response areas of 333 inferior collicular (ic) neurons of eptesicus fuscus were studied under free-field acoustic stimulus conditions. a stimulus was delivered from a loudspeaker placed 14 cm in front of a bat and the best frequency of an encountered neuron was determined. then a best frequency (bf) stimulus was delivered as the loudspeaker was moved across the frontal auditory space to determine the response center of the neuron. at the response center, the neuron had the l ...19873676742
auditory spatial response areas of single neurons and space representation in the cerebellum of echo locating bats.using free-field acoustic stimulation conditions, we studied the auditory spatial response areas of 242 cerebellar neurons of eptesicus fuscus. a best frequency stimulus was delivered from a loudspeaker which was moved across the frontal auditory space in order to determine the response center of each cerebellar neuron. at the response center, the neuron had its lowest minimum threshold. the stimulus was then raised 5-15 db above the lowest minimum threshold of each neuron and the spatial respon ...19873620934
pinna position affects the auditory space representation in the inferior colliculus of the fm bat, eptesicus fuscus.using free-field acoustic stimulus conditions, we studied the auditory space representation in the inferior colliculus (ic) of the big brown bat, eptesicus fuscus, under different pinna positions. stimuli were delivered from a loudspeaker placed 14 cm in front of the bat to determine the best frequency (bf) of an isolated neuron. a bf stimulus was then delivered as the loudspeaker was moved across the frontal auditory space of the bat to locate the response center of the neuron. at the response ...19873610849
anatomical study of neural projections to the superior colliculus of the big brown bat, eptesicus fuscus.auditory inputs to the intermediate and deep layers of the superior colliculus of the bat, eptesicus fuscus, were studied by iontophoretic injection of horseradish peroxidase (hrp) into the superior colliculus. hrp was injected into the recording sites of superior collicular neurons that responded to acoustic stimuli (4 ms duration, 0.5 ms rise-decay times). the results showed that the superior colliculus received its auditory projections mainly from the inferior colliculus bilaterally, but with ...19873620966
pathogenesis of rabies virus from a danish bat (eptesicus serotinus): neuronal changes suggestive of spongiosis.rabies virus strains isolated from a european bat (eptesicus serotinus) in denmark (dbv), a north american big brown bat (eptesicus fuscus) in new york state (ny-bat), and a human in south africa (duvenhage strain (duv-1) were studied by using a panel of monoclonal antibodies and by inoculating mice, cats, and dogs. the ten danish virus isolates from the same bat species reacted identically with a panel of monoclonal antibodies. immunofluorescence, monoclonal antibody, and histopathologic studie ...19883369944
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
bat rabies in british columbia 1971-1985.rabies virus was demonstrated in 99 of 1154 bats submitted from british columbia between 1971 and 1985. rabies was diagnosed in seven species including big brown bats (eptesicus fuscus), the latter accounting for 51% of all positive cases. colonial species represented 92.9% of all identified bats and 87.7% of all rabid cases. most bats were submitted from the more densely populated areas of the province, and submissions and positive cases both peaked in the month of august. daytime activity and ...198817422945
clutter interference along the target range axis in the echolocating bat, eptesicus fuscus.the sensitivity of the echolocating bat, eptesicus fuscus, for detection of a sonar target is impaired by the presence of additional targets located at similar distances. at a range of 54 cm, sensitivity to one target declines if the range separation to other targets is smaller than 8-9 cm. this loss of sensitivity is an example of clutter interference along the range axis, created by simultaneous masking of one set of echoes by another. echoes that fall within an experimentally defined critical ...19883170946
intracellular labeling of afferents to the lateral superior olive in the bat, eptesicus fuscus.an in vitro tissue slice preparation of the bat brain stem was used to label intracellularly individual axons projecting to the lateral superior olive from two different sources: the medial nucleus of the trapezoid body (mntb) and the anteroventral cochlear nucleus (avcn). the tracing of individually labeled mntb axons into the lateral superior olive reaffirms the long accepted indirect route by which information from the contralateral ear reaches the lateral superior olive. while the mntb appea ...19883170356
a view of the world through the bat's ear: the formation of acoustic images in echolocation.echolocating bats perceive objects as acoustic images derived from echoes of the ultrasonic sounds they emit. they can detect, track, identify, and intercept flying insects using sonar. many species, such as the big brown bat, eptesicus fuscus, emit frequency-modulated sonar sounds and perceive the distance to targets, or target range, from the delay of echoes. for eptesicus, a point-target's image has a sharpness along the range axis that is determined by the acuity of echo-delay perception, wh ...19892691182
the acoustic basis for target discrimination by fm echolocating bats.past experiments show that echolocating bats of the species myotis lucifugus and eptesicus fuscus can discriminate among airborne sonar targets presented in the context of pursuit maneuvers for the interception of prey. these bats distinguish between edible mealworms and inedible spheres of various sizes. myotis can distinguish between disks and mealworms similar enough in size that the bat's performance requires the ability to perceive the acoustic equivalent of target shape. previously observe ...19892808908
clutter interference and the integration time of echoes in the echolocating bat, eptesicus fuscus.the ability of the echolocating bat, eptesicus fuscus, to detect a sonar target is affected by the presence of other targets along the same axis at slightly different ranges. if echoes from one target arrive at about the same delay as echoes from another target, clutter interference occurs and one set of echoes masks the other. although the bat's sonar emissions and the echoes themselves are 2 to 5 ms long, echoes (of approximately equal sensation levels--around 15 db sl) only interfere with eac ...19892808907
range estimation by echolocation in the bat eptesicus fuscus: trading of phase versus time cues.bats of the species eptesicus fuscus have been trained to discriminate a stationary simulated target from a target with a virtual distance that jitters from sound to sound. similar to simmons [science 207, 1336-1338 (1979)], a jitter-detection threshold below 1 microsecond was found. however, simmons' decreased performance at a time delay jitter of 30 microseconds could not be replicated, a critical feature used to postulate the idea that bats employ a coherent cross-correlation receiver for ran ...19892745884
frequency and space representation in the primary auditory cortex of the frequency modulating bat eptesicus fuscus.1. frequency and space representation in the auditory cortex of the big brown bat, eptesicus fuscus, were studied by recording responses of 223 neurons to acoustic stimuli presented in the bat's frontal auditory space. 2. the majority of the auditory cortical neurons were recorded at a depth of less than 500 microns with a response latency between 8 and 20 ms. they generally discharged phasically and had nonmonotonic intensity-rate functions. the minimum threshold, (mt) of these neurons was betw ...19892585357
bat rabies in illinois: 1965 to 1986.from 1968 to 1986, illinois (usa) citizens and agencies submitted 4,272 bats to the illinois department of public health for rabies testing. of this number, 6% tested positive, a rate comparable to similar studies from other parts of north america. due to sampling biases, the true infection rate among bats in illinois is probably lower than 6%. additional analysis relied on a subsample (n = 2,433) of the specimens collected from 1965 to 1986. prevalences were significantly different among years, ...19892915390
nigrotectal projection to the inferior colliculus: horseradish peroxidase transport and tyrosine hydroxylase immunohistochemical studies in rats, cats, and bats.the present study investigated descending projections from the substantia nigra to the auditory tectum. small (0.02-0.05 microliters) injections of a 30-60% aqueous solution of horseradish peroxidase (hrp) were made unilaterally into the inferior colliculus in rats, cats, and bats (eptesicus fuscus). tissue blocks including the substantia nigra, superior colliculus, and inferior colliculus were removed, sectioned, and processed for visualization of hrp. results show that the substantia nigra, pa ...19892565350
discrimination of jittered sonar echoes by the echolocating bat, eptesicus fuscus: the shape of target images in echolocation.1. behavioral experiments with jittering echoes examined acoustic images of sonar targets in the echolocating bat, eptesicus fuscus, along the echo delay or target range axis. echo phase, amplitude, bandwidth, and signal-to-noise ratio were manipulated to assess the underlying auditory processes for image formation. 2. fine delay acuity is about 10 ns. calibration and control procedures indicate that this represents temporal acuity rather than spectral discrimination. jitter discrimination curve ...19902074548
auditory response properties and directional sensitivity of cerebellar neurons of the echolocating bat, eptesicus fuscus.auditory response properties and directional sensitivity of cerebellar neurons of eptesicus fuscus were studied under free-field stimulation conditions. the best frequency (bf) and minimum threshold (mt) of a recorded neuron were first determined with a sound delivered in front of the bat. discharge pattern and mt were studied with both bf stimuli and one-octave downward and upward sweep fm (frequency-modulated) stimuli. the directional sensitivity of cerebellar neurons was then studied by deter ...19902245329
convergence of temporal and spectral information into acoustic images of complex sonar targets perceived by the echolocating bat, eptesicus fuscus.1. fm echolocating bats (eptesicus fuscus) were trained to discriminate between a two-component complex target and a one-component simple target simulated by electronically-returned echoes in a series of experiments that explore the composition of the image of the two-component target. in experiment i, echoes for each target were presented sequentially, and the bats had to compare a stored image of one target with that of the other. the bats made errors when the range of the simple target corres ...19902332837
frequency and space representation in the inferior colliculus of the fm bat, eptesicus fuscus.the tonotopic organization and spatial sensitivity of 217 inferior collicular (ic) neurons of eptesicus fuscus were studied under free field stimulation conditions. acoustic stimuli were delivered from a loudspeaker placed 21 cm ahead of the bat to determine the best frequency (bf) and minimum threshold (mt) of isolated ic neurons. a bf stimulus was then delivered as the loudspeaker was moved horizontally across the frontal auditory space of the bat to locate the best azimuthal angle (baz) at wh ...19902311706
influence of monaural plugging on postnatal development of auditory spatial sensitivity of inferior collicular neurons of the big brown bat, eptesicus fuscus.postnatal development of auditory sensitivity in the big brown bat, eptesicus fuscus, was studied by determining the auditory spatial sensitivity of inferior collicular (ic) neurons of juvenile bats which were raised under normal (control) or monaurally plugged conditions. the auditory spatial sensitivity of each ic neuron was determined by measuring its variation in number of impulses and minimum threshold to a best frequency sound delivered from different azimuthal angles under free field stim ...19902269023
encoding repetition rate and duration in the inferior colliculus of the big brown bat, eptesicus fuscus.1. encoding of temporal stimulus parameters by inferior collicular (ic) neurons of eptesicus fuscus was studied by recording their responses to a wide range of repetition rates (rrs) and durations at several stimulus intensities under free field stimulus conditions. 2. the response properties of 424 ic neurons recorded were similar to those reported in previous studies of this species. 3. ic neurons were classified as low-pass, band-pass, and high-pass according to their preference for rrs and/o ...19911941720
arctiid moth clicks can degrade the accuracy of range difference discrimination in echolocating big brown bats, eptesicus fuscus.four big brown bats (eptesicus fuscus) born and raised in captivity were trained using the yes/no psychophysical method to report whether a virtual sonar target was at a standard distance or not. at threshold bats were able to detect a minimum range difference of 6 mm (a delta t of 36 microseconds). following threshold determinations, a click burst 1.8 ms long containing 5 pulses from the ruby tiger moth, phragmatobia fuliginosa (arctiidae), was presented randomly after each phantom echo. the so ...19911920158
discrimination of wingbeat motion by bats, correlated with echolocation sound pattern.bats of the species rhinolophus rouxi, hipposideros lankadiva and eptesicus fuscus were trained to discriminate between two simultaneously presented artificial insect wingbeat targets moving at different wingbeat rates. during the discrimination trials, r. rouxi, h. lankadiva and e. fuscus emitted long-cf/fm, short-cf/fm and fm echolocation sounds respectively. r. rouxi, h. lankadiva and e. fuscus were able to discriminate a difference in wingbeat rate of 2.7 hz, 9.2 hz and 15.8 hz, respectively ...19912046046
encoding of acoustic stimulus intensity by inferior collicular neurons of the big brown bat, eptesicus fuscus.using bats as a model system, we studied the isointensity and isofrequency discharge rate functions of inferior collicular (ic) neurons under free field stimulation conditions in order to understand how the midbrain auditory neurons encode stimulus intensity. for each encountered ic neuron, the best frequency (bf), minimum threshold (mt), tuning curve and intensity rate function for the bf were first determined. then at a fixed stimulus intensity, the number of impulses was measured for several ...19911959436
directional sensitivity of bat inferior collicular neurons determined under normal and monaurally plugged ear conditions.in an effort to further understand the combined effect of binaural intensity difference and pinna position on the directional sensitivity of an auditory neuron, we used free field stimulation to study the directional sensitivity of inferior collicular (ic) neurons of the big brown bat, eptesicus fuscus, under the following three ear conditions: normal ears, monaurally plugged ear and monaurally plugged plus pinna bending backward. the best frequency (bf) and minimum threshold (mt) of each neuron ...19911820843
nutritional implications for nitrogen and mineral budgets from analysis of guano of the big brown bat eptesicus fuscus (chiroptera: vespertilionidae).1. analysis of nitrogen, sodium, calcium, magnesium, iron, and potassium levels in big brown bat guano throughout much of the summer roosting period was performed. 2. based on the tenet that low, non-variable levels of an element in feces indicate dietary inadequacy for that element, female big brown bats are routinely and severely stressed for calcium and may become stressed for iron by the end of the summer. similar elemental stresses, although not as severe, exist for males.19911685367
the monaural nuclei of the lateral lemniscus in an echolocating bat: parallel pathways for analyzing temporal features of sound.in echolocating bats, three cell groups in the lateral lemniscus are conspicuous for their large size and high degree of differentiation. these cell groups are the intermediate nucleus (inll), columnar nucleus (vnllc), and multipolar cell area (vnllm). all receive projections from the contralateral cochlear nucleus. previous anatomical studies suggest the hypothesis that these nuclei are important for analyzing the temporal structure of sound. to investigate this possibility, we recorded respons ...19911941092
auditory response properties and spatial response areas of single neurons in the pontine nuclei of the big brown bat, eptesicus fuscus.using free-field acoustic stimulation conditions, we studied the response properties and spatial sensitivity of 146 pontine neurons of the big brown bat, eptesicus fuscus. the best frequency (bf) and minimum threshold (mt) of a pontine neuron were first determined with a sound broadcast from a loudspeaker placed ahead of the bat. a bf sound was delivered from the loudspeaker as it moved across the frontal auditory space in order to locate the response center at which the neuron had its lowest mt ...19921571779
sonar gain control and echo detection thresholds in the echolocating bat, eptesicus fuscus.the echolocating bat, eptesicus fuscus, detects sonar echoes with a sensitivity that changes according to the time elapsed between broadcasting of each sonar signal and reception of echoes. when tested in an electronic target simulator on a two-choice echo-detection task, the bat's threshold improved by 11.5 db as echo delay changed from 2.3 to 4.6 ms (target ranges of 40 and 80 cm). earlier experiments measured the change in detection threshold for delays from 1 to 6.4 ms (target ranges from ab ...19921556314
stabilization of perceived echo amplitudes in echolocating bats. ii. the acoustic behavior of the big brown bat, eptesicus fuscus, when tracking moving prey.big brown bats, eptesicus fuscus, can be trained to use echolocation to track a small microphone with a food reward attached when it is moved rapidly toward them. this situation mimics prey interception in the wild while allowing very precise recording of the sonar pulses emitted during tracking behavior. the results show that e. fuscus intensity compensates, reducing emitted intensity by 6 db per halving of target range so that the intensity incident upon the target is constant and echo intensi ...19921556313
stabilization of perceived echo amplitudes in echolocating bats. i. echo detection and automatic gain control in the big brown bat, eptesicus fuscus, and the fishing bat, noctilio leporinus.previous research on echo detection in bats has suggested that the effective threshold is a function of the acoustic clutter in the experimental environment, as might be expected given the low ambient noise levels typical of such psychophysical research. this paper demonstrates that theory of signal detectability (tsd) methodology is applicable to bats and uses it to show that an important element of clutter limiting in eptesicus fuscus and noctilio leporinus is backward masking of phantom targe ...19921313464
apneic oxygen uptake in the torpid bat, eptesicus fuscus.like many mammalian heterotherms, the big brown bat, eptesicus fuscus, breathes intermittently during torpor. by exploiting this bat's preference to roost in crevices, we could separately measure o2 uptake during ventilatory bouts and apneic periods using a flow-through metabolic chamber with a small dead space volume and short time constant. oxygen uptake was measured during apneas ranging from 10 to 150 min duration at body temperatures of 20, 10 and 5 degrees c. the fraction of total o2 uptak ...19921487714
frequency tuning properties of neurons in the inferior colliculus of an fm bat.we examined frequency tuning characteristics of single neurons in the inferior colliculus of the echolocating bat, eptesicus fuscus, in order to determine whether there are different classes of spectral selectivity at this level and to relate frequency tuning properties to the design of the echolocation signal. in unanesthetized but tranquilized animals, we recorded responses from 363 single units to pure tones, frequency-modulated (fm) sweeps, or broad-band noise. most units were selective for ...19921592904
pulse repetition rate and duration affect the responses of bat auditory cortical neurons.under free field stimulation conditions, we studied the effect of pulse repetition rate and duration on the responses of auditory cortical neurons of the big brown bat, eptesicus fuscus. the best frequency (bf) and minimum threshold (mt) of each recorded neuron were first determined with a 4 ms pulse delivered from a specific point of the bat's frontal auditory space at which the neuron had maximal spatial sensitivity. then a 4 ms pulse was delivered repetitively at different rates with an inten ...19921308731
immunocytochemical localization of luteinizing hormone-releasing hormone (lhrh) in the nervus terminalis and brain of the big brown bat, eptesicus fuscus.little is known about the immunohistochemistry of the nervous system in bats. this is particularly true of the nervus terminalis, which exerts strong influence on the reproductive system during ontogeny and in the adult. luteinizing hormone-releasing hormone (lhrh) was visualized immunocytochemically in the nervus terminalis and brain of juvenile and adult big brown bats (eptesicus fuscus). the peripheral lhrh-immunoreactive (ir) cells and fibers (nervus terminalis) are dispersed along the basal ...19921740548
ectoparasitic mites (acari) of sympatric brazilian free-tailed bats and big brown bats in alabama.seven species of mites were recovered from 133 brazilian free-tailed bats, tadarida brasiliensis, and 94 big brown bats, eptesicus fuscus, from february through november 1990 in colonies that shared roosting space in east-central alabama. the macronyssid chiroptonyssus robustipes (ewing) was the most common mite on t. brasiliensis (964 mites, 87% of bats infested) and on e. fuscus (109 mites, 29% of bats infested). however, c. rubustipes normally is a specific parasite of t. brasiliensis. the ma ...19921625301
rabid bat diagnosed in hawaii.since 1966, the hawaii state government has been conducting fluorescent rabies antibody (fra) testing on animal brains as part of a statewide rabies-surveillance program. on april 3, 1991, the department of health (doh) laboratory diagnosed the first case of rabies detected in the state. a large brown bat, eptesicus fuscus fuscus, captured in a transport container that had just been off-loaded from a ship at honolulu harbor, was caught. it's brain was examined and showed typical fluorescent stai ...19921517074
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