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PubMed1987

Changes in Leydig cell activity during the annual testicular cycle of the bat Myotis lucifugus lucifugus: histology and lipid histochemistry.

Changes in Leydig cell histology and testicular sudanophilic lipids were examined in relation to spermatogenic activity in the bat Myotis lucifugus lucifugus (Chiroptera: Vespertilionidae) throughout the annual cycle in the northeastern United States. These changes were correlated with annual variations in plasma testosterone concentrations which have recently been described for this species. Gametogenic activity occurred during the months of May-August when bats were metabolically most active. During hibernation (October-April), when sperm are stored in the epididymides, and accessory glands are hypertrophic, the seminiferous tubules were at rest, and the germinal epithelium was reduced to reserve spermatogonia and Sertoli cells. Based on their structure and cyclic pattern of sudanophilic lipids, Leydig cells exhibited a pattern of activity that closely paralleled that of the seminiferous epithelium. On renewal of spermatogenesis in spring, Leydig cells became hypertrophied and accumulated lipid inclusions. These inclusions, seen as vacuoles in plastic sections and sudanophilic droplets in frozen sections, reached maximal accumulations in late June. In late July and during August, when peak testosterone levels occur in blood, lipid droplets were dramatically depleted, and Leydig cells were weakly sudanophilic. In September, when testosterone titers return to low baseline levels, Leydig cells had regressed but exhibited a marked increase in sudanophilic inclusions which appeared to be mostly lipofuscins. During the ensuing mating and hibernation periods, Leydig cells were involuted and filled with lipofuscins. During the periarousal period, however, Leydig cells became weakly Sudan-positive while many large, intensely sudanophilic cells were scattered throughout the interstitium. In electron micrographs these cells were identified as macrophages. They appear to play an important role in the annual testicular cycle by phagocytizing the residues of Leydig cell involution in preparation for a new steroidogenic cycle. Seasonal changes in lipid inclusions were also observed in the seminiferous tubules. In addition, the relationship of the Leydig cell cycle to androgen action and the accessory organs in this bat is discussed.

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PubMed1987

Annual skeletal changes in the little brown bat, Myotis lucifugus lucifugus, with particular reference to pregnancy and lactation.

Studies of bone from summer-active little brown bats, Myotis lucifugus lucifugus, have demonstrated sex differences in the renewal of skeletal mineral reserves following spring-arousal from hibernation. Patterns of bone remodeling in both sexes of bats indicate that new bone formation does not occur during hibernation: All new bone formation occurs during the summer-active season. Results show that a short period of time elapses after hibernation before the initial demands of a large fetus and rapidly growing neonate are expressed on maternal skeletal reserves. Bone loss in summer-active females was associated with pregnancy and lactation, whereas summer-active males did not show evidence of bone loss but, instead, uninterrupted bone accretion throughout the summer-active season. Osteoclasts and bone-forming osteoblasts, absent during the hibernation period, reappeared on bone surfaces following spring-arousal from hibernation. There was no apparent increase in osteoclast numbers or activity during lactation but resorption cavities were found in deep cortical lamellae distant from bone surfaces. The increase in bone resorption in lactating bats appeared to be by osteocytic osteolysis, suggesting that it might be a significant mechanism of bone/calcium regulation in this hibernating mammal throughout the year.

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PubMed1991

Brain growth and differentiation in two fetal bats: qualitative and quantitative aspects.

The development of the main brain components in two fetal bats (one insectivorous and one frugivorous type) is studied quantitatively and comparatively. The telencephalon, cerebellum, and diencephalon grow faster in the frugivorous bat. The brainstem maintains a greater relative volume throughout in the insectivorous type. The morphology and density of neurons in the cerebellum, caudate nucleus, olfactory mitral stratum, and neocortical layer II suggest that there exists an initial delay in development in the frugivorous bat; through subsequent reordering, however, it becomes more advanced in development, in accordance with the more progressive status of the adult forms in its category. In this there may be a certain ontogenetic recapitulation of a possible chiropteran phylogeny. These comparisons also point to the precociousness of the functional determination of those structures that are related to future behavior in a purely deterministic, non-teleological sense. The qualitative differentiation appears to be more significant than might be expected in comparison with the quantitative proliferation. Technical problems involved in the study of brain morphogenesis are discussed, especially the difficulty of distinguishing the respective effects of cell multiplication, cell death, and artificial increase in cell density through tissue shrinkage.

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PubMed1976

Reproductive biology of the male leaf-nosed bat, Macrotus waterhousii in Southwestern United States.

The reproductive biology of the bat Macrotus waterhousii was investigated anatomically and physiologically several times monthly throughout the year. The male spermatogenic cycle is initiated in June; sperm are available in August. Testicular hypertrophy is accompanied by increased levels of testicular ascorbic acid and circulating plasma testosterone. Sperm are present in the seminiferous tubules and later the epididymides from August to early December. Regression in testicular size begins in late September and testes are involuted by early December. Levels of testicular ascorbic acid and plasma testosterone decline at this time, although detectable amounts of both are present year-round. Mature sperm are absent from the male tract after late November or early December. The accessory sex gland complex and Cowper's glands undergo an annual cycle in synchrony with the testicular cycle. The accessory complex contains fructose, the concentration of which varies seasonally in direct proportion to glandular hypertrophy. Only trace levels of fructose are elaborated by Cowper's glands undergo an annual cycle in synchrony with the testicular cycle. The accessory complex contains fructose, the concentration of which varies seasonally in direct proportion to glandular hypertrophy. Only trace levels of fructose are elaborated by Cowper's glands. In contrast to vespertilionid bats, where the accessory glands remain enlarged and active when testes involute, those in Macrotus regress. The penis differs structurally from that of other temperate North American bats, primarily by lacking a bony baculum and specialized erectile accessory corpus cavernosus bodies. Males are not reproductively active in their first autumn.

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PubMed1983

Distribution and size of Boettcher cells in the little brown bat, rabbit, and other species.

The distribution and size of Boettcher cells were determined from serial sections of the temporal bones of four little brown bats and six rabbits. In addition, one harp seal and one two-toed sloth were examined. In the little brown bat, the heights of the Boettcher cells measured 4-8 micron and they were found throughout much of the length of the cochlea. There were four rows in most of the lower basal coil, five rows in the upper basal coil, and four rows in the middle coil. In the rabbit there were nine rows in the basal coil and 12 rows in the middle coil. The heights of the Boettcher cells were approximately 14 micron in the rabbit. In the two-toed sloth, Boettcher cells were sparsely distributed along the basal coil; similarly, in the harp seal, Boettcher cells were confined solely to the basal coil, where there were only three rows, which measured approximately 18 micron in height. The distribution and size of Boettcher cells in the rabbit and the little brown bat were compared to those in other mammalian species.

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PubMed1994

Mucous droplets with multiple membranes in the accessory submandibular glands of long-winged bats.

BACKGROUND: Certain species of bats possess two sets of submandibular glands, namely, principal and accessory. The ultrastructure and histochemistry of the accessory submandibular gland was examined in three species of long-winged bats. METHODS: Specimens of Miniopterus schreibersi and M. magnator were live-trapped in Thailand, and of M. inflatus were live-trapped in Kenya. For electron microscopy, accessory submandibular lands were initially fixed in triple aldehyde-DMSO, postfixed in osmium tetroxide, and embedded in Epon-Maraglas. A portion of the glands collected in Thailand (M. schreibersi and M. magnator) was fixed in buffered formalin and embedded in paraffin. Sections of the latter material were subjected to a battery of histochemical tests for glycoconjugates. RESULTS: Although in all three species the accessory submandibular glands have normal histological structure, the glands in two, M. schreibersi and M. magnator, were distinguished by possessing mucous droplets of unusual morphology. These droplets, whose identity as mucous was confirmed by histochemical tests for glygoconjugates, are delimited by manifold membranes: up to 10 in M. schreibersi and fewer, but still multiple, in M. magnator. In both species, the entire array of surface membranes may fold inward in the fashion of mitochondrial cristae, forming packets of membranes, many of which have the spurious appearance of floating free in the droplet matrix. These multipartite limiting membranes appear to originate simply by Golgi saccules and moderately large, flattened Golgi vesicles repeatedly wrapping themselves around the surface of nascent mucous droplets. During exocytosis, the outermost membrane of each mucous droplet contacts the luminal membrane, this barrier ruptures, then the remainder of the droplet--multiple membranes and matrix--either flow into the lumen or are cast out in toto. In either case, a great deal of membrane phospholipid is added to the saliva. This salivary lipid may permit these bats to consume insects that normally are able to repel predators with chemical defenses that make them unpalatable. The third species that we studied, M. inflatus, has mucous droplets of normal appearance, i.e., they have only one limiting membrane. CONCLUSIONS: The varying structure of mucous secretory products among the species of Miniopterus provides important clues as to the evolution of this genus as well as to the evolution of secretory cells in general.

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PubMed1995

Patella of selected bats: patterns of occurrence or absence and associated modifications of the quadriceps femoris tendon.

BACKGROUND: Having observed the apparent absence of a bony patella in a Madagascar flying fox (Pteropus sp.), other species from the two suborders of bats (Megachiroptera and Microchiroptera) were examined to determine the presence or absence of a bony patella and the distribution of this feature among bats. METHODS: Gross, radiographic, and histologic examination of seven megachiropteran species representing four genera, as well as six microchiropteran species representing six genera, was performed. RESULTS: A bony patella was observed in all six microchiropteran and in three megachiropteran species. The tendon of the quadriceps femoris muscle in Microchiropteran species was composed mainly of dense regular connective tissue. The quadriceps tendon in Megachiropteran species with a patella contained an abundance of fibrocartilage and hyaline cartilage, unlike the quadriceps femoris tendon of the Microchiroptera or a laboratory mouse examined for comparison. CONCLUSIONS: Four species of the megachiropteran genus Pteropus lacking a bony patella displayed a similar occurrence and distribution of fibrocartilage and hyaline cartilage within the quadriceps tendon as seen in the other bats. In reference to this singular feature, Pteropus is unique among the representatives of megachiropteran and microchiropteran genera examined here.

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PubMed1981

The connections of the inferior colliculus and the organization of the brainstem auditory system in the greater horseshoe bat (Rhinolophus ferrumequinum).

The connections of the inferior colliculus, the mammalian mid-brain auditory center, were determined in the greater horseshoe bat (Rhinolophus ferrumequinum), using the horseradish peroxidase method. In order to localize the auditory centers of this bat, brains were investigated with the aid of cell and fiber-stained material. The results show that most auditory centers are highly developed in this echolocating bat. However, the organization of the central auditory system does not generally differ from the mammalian scheme. This holds also for the organization of the superior olivary complex where a well-developed medial superior olivary nucleus was found. In addition to the ventral and dorsal nuclei of the lateral lemniscus a third well-developed nucleus has been defined which projects ipsilaterally to the inferior colliculus and which was called the intermediate nucleus of the lateral leminiscus. All nuclei of the central auditory pathway project ipsi-, contra-, or bilaterally to the central nucleus of the inferior colliculus with the exception of the medial nucleus of the trapezoid body and the medial geniculate body. The tonotopic organization of these projections and their possible functions are discussed in context with neurophysiological investigations.

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PubMed1985

Topology of the central nucleus of the mustache bat's inferior colliculus: correlation of single unit properties and neuronal architecture.

The central nucleus of the mustache bat's inferior colliculus was studied in Golgi, Nissl, and fiber stained preparations; the neuronal organization and cytoarchitecture were correlated with the tonotopic maps revealed by single cell recordings. Three divisions of the central nucleus were defined by anatomical and physiological criteria: the anterolateral, medial, and dorsoposterior divisions. In horizontal sections, the anterolateral division has pronounced, semicircular fibrodendritic laminae. The dendritic fields of adjacent neurons form rostro-caudally-oriented laminae related to the tonotopic sequence. The neurons in the medial division are similar in size and arrangement, but here the laminar orientation follows the lateral-to-medial axis, with less curvature. The dorsoposterior division has many small disc-shaped and stellate neurons and a different, somewhat less fully expressed, laminar orientation. Each division has a unique frequency representation and tonotopic organization which conform to the pattern of dendritic orientation. In the anterolateral division, frequencies from about 10 kHz to about 59 kHz are represented, whereas the frequency representation in the medial division ranges from about 65 kHz to 110 kHz, and higher. The dorsoposterior division has an isofrequency organization in which the best frequency is characteristic for each bat, ranging from 60 to 64 kHz and varying by only +/- 300 Hz. This frequency corresponds to the dominant echo frequency of the bat's echolocation signals. We suggest that the dorsoposterior division is a hypertrophied isofrequency lamina, with many neurocytological features comparable to the isofrequency laminae in the central nucleus of other mammals.

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PubMed1991

Pattern of retinotectal projection in the megachiropteran bat Rousettus aegyptiacus.

The retinotopic organisation of the superior colliculus (SC) in the megachiropteran bat Rousettus aegyptiacus was examined with single and multi-unit recordings and by tracing the retrograde and anterograde transport of horseradish peroxidase (HRP) between the retina and the SC. The pattern of projection of the visual field onto the SC in Rousettus resembles the pattern found in most mammals. The whole of the contralateral visual field is represented and, in addition, a region of the ipsilateral visual field extending 25 degrees beyond the vertical 0 degree meridian. The ipsilateral visual field is represented binocularly in the most anterior 300-500 microns of the rostral pole of the SC. The contralateral visual field up to 25 degrees from the vertical meridian is represented through both eyes for the next 500-800 microns. The peripheral part of the contralateral visual field, 25 degrees-110 degrees from the vertical meridian is seen only by the nasal retina (the monocular crescent) of the contralateral eye and is represented in the caudal part of the SC. Following multiple injections of HRP into one SC, ganglion cells were labeled in both the nasal and temporal hemiretina of the contralateral eye. In the retina ipsilateral to the injection site, labeled cells were restricted to the temporal hemiretina. After injections of HRP into one eye, labeled terminals were found all over the contralateral SC, but in the ipsilateral SC they were restricted to a band that begins 300-500 microns caudal from the rostral pole and extends to the middle of the SC. These results suggest that in Rousettus, unlike the megachiropteran bats described by Pettigrew, Jamieson, Robson, Hall, McAnally, and Cooper (Philosophical Transactions of the Royal Society of London Series B 325:489-559, 1989), the retinotopic organisation of the SC is not primate-like, but follows the general mammalian scheme. As the retinotopic organisation of the SC is not consistent among the megachiropteran bats, the pattern of this projection may not be a useful indicator of their phylogenetic origins.

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PubMed1992

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 surface of the forebrain from the olfactory bulbs to the prepiriform cortex and the interpeduncular fossa. A concentration of peripheral LHRH-ir perikarya and fibers was found at the caudalmost part of the olfactory bulbs, near the medioventral forebrain sulcus; obviously these cells mediate between the bulbs and the remaining forebrain. Within the central nervous system (CNS), LHRH-ir perikarya and fibers were distributed throughout the olfactory tubercle, diagonal band, preoptic area, suprachiasmatic and supraoptic nuclei, the bed nuclei of stria terminalis and stria medullaris, the anterior lateral and posterior hypothalamus, and the tuber cinereum. The highest concentration of cells was found within the arcuate nucleus. Fibers were most concentrated within the median eminence, infundibular stalk, and the medial habenula. The data obtained suggest that this distribution of LHRH immunoreactivity may be characteristic for microchiropteran (insectivorous) bats. The strong projections of LHRH-containing nuclei in the basal forebrain (including the arcuate nucleus) to the habenula, may indicate close functional contact between these brain areas via feedback loops, which could be important for the processing of thermal and other environmental stimuli correlated with hibernation.

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PubMed1994

Cytoarchitecture of the medial geniculate body in the mustached bat (Pteronotus parnellii).

The cytoarchitectonic organization of the medial geniculate body and adjoining thalamic nuclei was analyzed in the mustached bat (Pteronotus parnellii). These subdivisions provide a reference for structural, physiological, connectional, and neurochemical work. Most nuclei recognized in other mammals exist in the mustached bat, although the relative volume of the three divisions was species specific. The ventral division contains medium-sized neurons and a few smaller cells and is well developed. Neurons in the lateral part lie in regularly aligned rows corresponding to the laminae in Golgi material; in the medial part, these laminae are obscured by fibers. The dorsal division has at least four nuclei, each with a unique cytoarchitecture and myeloarchitectonic organization. The suprageniculate nucleus is prominent and has many large radiate neurons. Cells in the superficial dorsal nucleus have weekly laminated dendrites, while dorsal nucleus neurons have spherical dendritic fields. There is a wide range of neuropil patterns within the dorsal division. The suprageniculate nucleus has thick myelinated axons, while the fibers in the superficial and dorsal nuclei are much thinner. The rostral pole nucleus becomes prominent in the anterior one-half of the auditory thalamus; its architectonic affiliation is equivocal, and connectional and immunocytochemical studies suggest that it may belong to the dorsal division. The medial division is one nucleus with many types of neurons, and it has coarse axons without laminar orientation. It is the smallest of the divisions and is present throughout the medial geniculate complex, except at the caudal tip and at the rostral pole. Many features of medial geniculate body organization evident in other mammals are recognized in the mustached bat. These include a prominent ventral division, some of whose neurons have a laminar organization, and a comparatively small medial division that is devoid of fibrodendritic laminae. Other features, such as the presence of a large rostral pole nucleus, whose homologue in other species is uncertain, or the sparse number or small cells that may participate in local circuits, set it apart from carnivores and primates and suggest that there are species specific patterns of medial geniculate body organization.

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PubMed1994

Nature and origin of cerebrovascular nerves with substance P immunoreactivity in bats (Mammalia: Microchiroptera), with special reference to species differences.

Double staining immunohistochemistry was used to investigate the origin and projection of nerves with substance P (SP) immunoreactivity (-IR) in the walls of the major cerebral arteries in two microchiropteran species. In the greater horseshoe bat, most of the cerebral perivascular nerves with SP-IR did not exhibit calcitonin gene-related peptide (CGRP)-IR, but emitted bright immunofluorescence for vasoactive intestinal polypeptide (VIP). In this species, a large number of cell bodies with both SP- and VIP-IR were observed in many cranial ganglia along various branches of the facial and glossopharyngeal nerves. There were no cell bodies immunoreactive for either SP and VIP in the two sensory (trigeminal and upper cervical dorsal root), two sympathetic (superior cervical and stellate), or two vagal (superior and jugular) ganglia. In addition, several thick fiber bundles with both SP- and VIP-IR were present in the wall of the cerebral carotid artery, and descended progressively reaching as far as the middle part of the basilar artery (BA). These and other findings suggest that SP-immunoreactive nerves with VIP-IR but not CGRP-IR, which contribute to the rich innervation of the vertebrobasilar system in the greater horseshoe bat, originate from neurons with the same combination of peptide-IR in the major or local facial or glossopharyngeal parasympathetic ganglia, and enter the cranial cavity along the internal carotid artery. In the bent-winged bat, however, cerebral perivascular SP-immunoreactive nerves, as well as SP-immunoreactive neurons within the trigeminal and upper cervical dorsal root ganglia (uCDRG), showed neither CGRP-IR nor VIP-IR, and were mostly confined to the caudal BA and the vertebral artery (VA). These observations, in addition to the projection of this nerve type to the BA via the VA as fiber bundles, or through the meninges, indicate that the principal source of the cerebrovascular SP-immunoreactive innervation in this species is the uCDRG.

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PubMed1995

GABA and glycine in the central auditory system of the mustache bat: structural substrates for inhibitory neuronal organization.

The distribution and morphology of neurons and axonal endings (puncta) immunostained with antibodies to gamma-aminobutyric acid (GABA) and glycine (Gly) were analyzed in auditory brainstem, thalamic, and cortical centers in the mustache bat. The goals of the study were (1) to compare and contrast the location of GABAergic and glycinergic neurons and puncta, (2) to determine whether nuclei containing immunoreactive neurons likewise have a similar concentration of puncta, (3) to assess the uniformity of immunostaining within a nucleus and to consider regional differences that were related to or independent of cytoarchitecture, and (4) to compare the patterns recognized in this bat with those in other mammals. There are nine major conclusions. (1) Glycinergic immunostaining is most pronounced in the hindbrain. (2) In the forebrain, GABA alone is present. (3) Some nuclei have GABAergic or glycinergic neurons exclusively; a few have neither. (4) Although there is sometimes a close relationship between the relative number of immunopositive neurons and the density of the puncta, just as often there is no particular correlation between them; this reflects the fact that many GABAergic and glycinergic neurons project beyond their nucleus of origin. (5) Even nuclei devoid of or with few GABAergic or glycinergic neurons contain relatively abundant numbers of puncta; some neurons receive axosomatic terminals of each type. (6) In a few nuclei there are physiological subregions with specific local patterns of immunostaining. (7) The patterns of immunostaining resemble those in other mammals; the principal exceptions are in nuclei that, in the bat, are hypertrophied (such as those of the lateral lemniscus) and in the medial geniculate body. (8) Cellular colocalization of GABA and Gly is specific to only a few nuclei. (9) GABA and glutamic acid decarboxylase (GAD) immunostaining have virtually identical distributions in each nucleus. Several implications follow. First, the arrangements of GABA and Gly in the central auditory system represent all possible patterns, ranging from mutually exclusive to overlapping within a nucleus to convergence of both types of synaptic endings on single neurons. Second, although both transmitters are present in the hindbrain, glycine appears to be dominant, and it is often associated with circuitry in which precise temporal control of aspects of neuronal discharge is critical. Third, the auditory system, especially at or below the level of the midbrain, contains significant numbers of GABAergic or glycinergic projection neurons. The latter feature distinguishes it from the central visual and somatic sensory pathways.

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PubMed1975

Experimental studies of the ontogeny of ultrasonic vocalizations in bats.

The ontogeny of FM pulses emitted by bats is a process of maturation that is not easily altered by experimental manipulation during early development. Infants that were hand-raised and infants that were raised by mothers with altered voices (the superior laryngeal nerves were cauterized pre- and postpartum) emitted normal adult calls. Effects of pinching the superior laryngeal nerves of young bats with a cold forcepts on their vocalizations suggest that the development of this nerve and its associated musculature occurs early in the bat's postnatal life.

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PubMed2004

Use of the wings in manipulative and suspensory behaviors during feeding by frugivorous bats.

Frugivory evolved independently in Old and New World fruit bats (Families Pteropodidae and Phyllostomidae, respectively) and anecdotal reports state that these bats use their wings in different ways for manipulating food items and postural support during feeding. However, these often-cited behavioral differences have not been documented systematically. Here we report observations of manipulative and suspensory behavior collected from 41 individuals representing five phyllostomid and six pteropodid species. During feeding, phyllostomids used both feet to suspend themselves and invariably manipulated food with the wrists and thumbs of both wings. Most pteropodids in our sample used their thumbs for suspension during feeding and none manipulated fruit with their wings. The suspensory and feeding behaviors of pteropodids varied widely and there were significant differences between species. Discrepancies between phyllostomids and pteropodids in the use of the wings during feeding are associated with previously reported differences in wrist morphology. Based on examination of manipulative and suspensory behaviors in a phylogenetic context, we suggest that differences between pteropodids and phyllostomids reflect the distinct ancestral conditions from which these bats evolved.

Animals↗
PubMed1979

A morphometric study of the cochlea of the little brown bat (Myotis lucifugus).

A detailed morphometric study of the basilar membrane was made from serial sections and graphic reconstructions of the cochlea of three little brown bats. Four distinct morphometric changes were observed within the basilar membrane. First, between 0-1.4 mm from the basal end of the cochlea, there is a rapid increase in width and cross-sectional area of the basilar membrane. Secondly, between 1.4-2.5 mm, there is little change in width of the basilar membrane (its cross-sectional area is at its greatest in this region). Thirdly, between 2.7-3.1 mm, there is a sudden decrease in cross-sectional area concomitant with an increase in the width of the basilar membrane. Finally, between 3.1 mm and the apex, there is a gradual decrease in cross-sectional area concomitant with an increase in the width of the basilar membrane. The magnitudes of the cross-sectional areas of the scalae media and vestibuli decrease from base to apex, but this is not true for the scala tympani. The cross-sectional area of the scala tympani appears to decrease from the base to 0.7 mm, then it increases up to 1.4 mm, and then it decreases to the apex. These morphometric changes in the basilar membrane of the little brown bat are compared to those in other echolocating and non-echolocating mammals. The significance of these changes is discussed in relation to the range of hearing in the little brown bat.

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PubMed2003

Case report: isolation of a European bat lyssavirus type 2a from a fatal human case of rabies encephalitis.

A 55-year-old bat conservationist was admitted to Ninewells Hospital, Dundee, Scotland, on November 11, 2002, with an acute haematemesis. He gave a 5-day history of pain and paraesthesia in the left arm, followed by increasing weakness of his limbs with evidence of an evolving encephalitis with cerebellar involvement. The patient had never been vaccinated against rabies and did not receive postexposure treatment. Using a hemi-nested reverse transcriptase-polymerase chain reaction (RT-PCR), saliva samples taken intravitam from different dates proved positive for rabies. A 400-bp region of the nucleoprotein gene was sequenced for confirmation and identified a strain of European bat lyssavirus (EBLV) type 2a. The diagnosis was confirmed using the fluorescent antibody test (FAT) and by RT-PCR on three brain samples (cerebellum, medulla, and hippocampus) taken at autopsy. In addition, a mouse inoculation test (MIT) was performed. Between 13 and 17 days postinfection, clinical signs of a rabies-like illness had developed in all five inoculated mice. Brain smears from each infected animal were positive by the FAT and viable virus was isolated. This fatal incident is only the second confirmed case of an EBLV type-2 infection in a human after exposure to bats.

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