The cytoarchitecture of the cochlear nuclear complex of two species of bats: Carollia perspicillata and Phyllostomus hastatus (original) (raw)
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European Journal of Lipid Science and Technology, 2013
The study was done to document and compare the cytoarchitectural details of the cochlear nuclear complex (CNC) in two species of bats with different forage strategies, Carollia perspicillata (fruit eating) and Phyllostomus hastatus (carnivorous/omnivorous). The CNC was larger and the subdivisions were distinct in P.hastatus than the C.perspillata. The CNC of both bats comprised of two main divisions: dorsal cochlear nucleus (DCN) and ventral cochlear nucleus (VCN). The DCN of both bats was further subdivided into two subdivisions: dorsomedial and ventromedial whereas the VCN was subdivided into three: anteroventral (AVCN), posteroventral . The main cell type of the DCN was small round cells measuring approximately 5 µm in diameter in both bats. The AVCN was principally made up of large multipolar cells (approximately 17 µm in diameter in C.perspicillata and 17-32 µm diameters in P.hastatus).The PVCN comprised of predominantly ovals cells measuring between 7.5 and 10 µm in diameter in both the bats. The LVCN comprised of small round cells with 5 µm in diameter in both the bats. The larger CNC with distinct subdivisions and the larger sized multipolar cells in the AVCN of the P.hastatus suggest that they depend mainly on echolocation for feeding while the C.perspillata, a fruit eating bat that uses echolocation to a lesser extent.
The study was done to document and compare the cytoarchitectural details of the cochlear nuclear complex (CNC) in two species of bats with different forage strategies, Carollia perspicillata (fruit eating) and Phyllostomus hastatus (carnivorous/omnivorous). The CNC was larger and the subdivisions were distinct in P.hastatus than the C.perspillata. The CNC of both bats comprised of two main divisions: dorsal cochlear nucleus (DCN) and ventral cochlear nucleus (VCN). The DCN of both bats was further subdivided into two subdivisions: dorsomedial and ventromedial whereas the VCN was subdivided into three: anteroventral (AVCN), posteroventral (PVCN) and a ventrolateral (LVCN). The main cell type of the DCN was small round cells measuring approximately 5 µm in diameter in both bats. The AVCN was principally made up of large multipolar cells (approximately 17 µm in diameter in C.perspicillata and 17-32 µm diameters in P.hastatus).The PVCN comprised of predominantly ovals cells measuring be...
International Journal of Life Science and Medical Research, 2013
The study was done to compare the cytoarchitecture of two species of bats to ascertain whether echolocation has a bearing on the development of the inferior colliculus. Six bats each of Noctilio leporinus and Phyllostomus hastatus were used for the study. The brains of these bats were processed by double embedding, serially sectioned at 10µm and stained with cresyl fast violet. The inferior colliculus measured 1200 ± 90µm in length in N. leporinus bat and 1120± 63 µm in P. hastatus bat. The inferior colliculus of the bats is subdivided into three parts: dorsomedial, ventromedial and the peripheral. Two types of cells are most common in the inferior colliculus of the bats: multipolar and oval. The inferior colliculus is very large in the two species of bats compared to other animals which do not echolocate and which may not have as good a sense of hearing as the bat. It is larger in the N. leporinus than in the P. hastatus bat suggesting that N. leporinus depends more on echolocation than P. hastatus. The large inferior colliculus in these bats may be related to an acute sense of hearing in these animals.
Annual Research & Review in Biology, 2014
The aim of the present study is to document cytoarchitectural details of Medial Geniculate Body (MGB) of the brain in three species of echolocating bats with different forage behavior. The brains were collected from six male adult bats of each species: Noctilio leporinus (fish-eating), Phyllostomus hastatus (carnivorous/ omnivorous) and Carollia perspicillata (fruit-eating) and were double-embedded and transverse serial sections were cut and stained with cresyl fast violet. The results showed that the mean length of the medial geniculate body was 1330 ± 115 µm in N. leporinus, 1210 ± 90 µm in P.hastatus and 790 ± 68 µm in C. perspicillata. The MGB of all three bats appeared to be divided into three divisions: dorsal (MGBd), ventral (MGBv) and medial (MGBm). These divisions were most distinct in the N. leporinus bat and least apparent in the C. perspicillata. In the N. leporinus, both dense-staining multipolar cells and light-staining round cells were located throughout the MGB. In the P. hastatus, the dense-staining multipolar cells were predominantly present in the ventral division of the middle third of the MGB, whereas lightstaining round cells predominated at the rostral end of the MGB. Only light-staining round 461 cells were seen throughout the MGB of the C. perspicillata. The large sized MGB and its clear subdivisions in N. leporinus suggests that it relies heavily on echolocation whereas P.hastatus and C. perspicillata use echolocation as well but also rely on hearing, smell and vision.
Brazilian Journal of Biology, 2019
The understanding of the echolocation by studying different auditory nuclei of echolocating bats can be an important link in elucidating questions arising in relation to their foraging behavior. The superior olivary complex (SOC) is the primary center for processing the binaural cues used in sound localization since echo locating bats rely on acoustic cues to navigate and capture prey while in flight. The present study was taken to test the hypothesis that the SOC of echolocating neotropical bats with different foraging behavior will exhibit morphological variations in relative size, degree of complexity and spatial distribution. The brains were collected from six male adult bats of each species: Noctilio leporinus (fish eating), Phyllostomus hastatus (carnivorous/omnivorous) and Carollia perspicillata (fruit eating). They were double-embedded and transverse serial sections were cut and stained with cresyl fast violet. The SOC measured as 640 ± 70 µm in the N. leporinus bat, 480 ± 5...
Brazilian Journal of Biology, 2020
The present study was taken to test the hypothesis that the medial nucleus of the trapezoid body (MNTB) of echolocating neotropical bats with different foraging behavior will exhibit morphological variations in relative size, degree of complexity and spatial distribution. The brains were collected from six male adult bats of each species: Noctilio leporinus (fish-eating), Phyllostomus hastatus (carnivorous/ omnivorous) and Carollia perspicillata (fruit-eating) and were double-embedded and transverse serial sections were cut and stained with cresyl fast violet. The results showed that the MNTB is well developed in all the bats in general and the mean length of the MNTB was 1160 ± 124 µm in N. leporinus, 400 ± 59 µm in P. hastatus and 320 ± 25µm in C. perspicillata. The body and brain weight do not reflect proportionately on the size of the MNTB in the present study. The hearing frequency spectrum did not covary with the size of the MNTB among the bats studied. The MNTB is clearly dem...
The cochlea of Tadarida brasiliensis: specialized functional organization in a generalized bat
Hearing Research, 1995
Tadarida brasiliensis mexicana employs a broad-band sonar system at frequencies between 8l) and 20 kHz and is characterized by non-specialized hearing capabilities. The cochlear frequency map was determined with extracellular horseradish peroxidase tracing in relation to quantitative morphological data obtained with light, scanning and transmission electron microscopy. These data reveal distinct species characteristic specializations clearly separate from the patterns observed in other bats with either broad-band or narrow-band sonar systems. The basilar membrane (BM) is coiled to 2.5 turns and about 12 mm long. Its thickness and width only change within the extreme basal and apical ends. The frequency range from about 30 to 80 kHz is represented in the lower basal turn with a typically mammalian mapping coefficient of about 3 mm/octave. This region exhibits morphological features correlated with non-specialized processing of high frequencies. (1) The BM is radially segmented by thickenings of pars tecta and pars pectinata. (2) The 3 rows of outer hair cells (OHCs) have similar morphology. Between 35 and 86% distance from base, frequencies between 30 and 12 kHz are represented with a slightly expanded mapping coefficient of about 6 mm/octave. In analogy to previous work, this cochlea region is termed 'acoustic fovea'. It includes the frequency range of maximum sensitivity and sharpest tuning (21-27 kHz) but also frequencies below the sonar signals. The fovea is characterized by several morphological specializations. (1) The BM features a continuous radial thickening mainly composed of hyaline substance. (2) There is an increased number of layers of tension fibroblasts in the spiral ligament. (3) There are morphological differences in the arrangements of stereocilia bundles among the 3 rows of OHCs. The transitions between non-specialized and specialized cochlear regions occur gradually within a distance of about 600 /xm. The gradients in stereocilia length of both receptor cell types and the gradations in length of the OHC bodies match specialized aspects of the frequency map.
The Journal of Comparative Neurology, 1989
The goals of this study were to describe the cochlear frequency map of the mustache bat, Pteronotus parnellii, and to relate the organization of cochlear primary afferents to that of the second-order projections from the cochlear nucleus to the superior olivary complex. Small deposits of horseradish peroxidase (HRP) were placed in the cochlear nucleus at sites that were physiologically characterized with respect to unit-best frequency. From the deposits, labeled fibers were traced in the retrograde direction to the cochlea and in the anterograde direction to the superior olive. Cochleas from both experimental and control animals were examined with light and electron microscopy. The peripheral axons of spiral ganglion neurons were counted in order to quantify the unusual variation in the innervation density along the cochlear spiral of the mustache bat. Regions of increased innervation density were found at the beginning and end of the basal turn of the cochlea. The highest cochlear innervation density consistently occurred in the upper basal turn. In horseradish peroxidase tracing experiments, this region contained labeled fibers only when HRP deposits were made at sites within the cochlear nucleus with unit-best frequencies around 60 kHz. These findings support the suggestion (Kossl and Vater, '85) that the cochlear sites of increased innervation density are related to the neural and behavioral emphasis that this echolocating bat places upon the analysis of the 60 kHz frequency band. The general arrangement of tonotopic maps within the cochlea, cochlear nucleus, and superior olive was consistent with previous observations in this bat and other mammalian species. At all three levels, there was evidence of a disproportionately large representation of frequencies around 60 kHz, similar to the enlarged representation reported within the inferior colliculus and auditory cortex of the mustache bat. In all cases there was a consistent relation between the size of the HRP deposit and the number and distribution of retrogradely labeled neurons in the cochlea. For most cases there was a similar relation between the size of the deposit and the terminal arborization field of anterogradely labeled fibers in the superior olive. However, in cases with deposits associated with the 60 kHz frequency band, the size of the labeled arborization field was more than twice as large as expected from the size of the deposits and from the extent of labeling in the cochlea. These cases suggest that the representation of frequencies around 60 kHz, already overrepresented in both the cochlea and cochlear nucleus, may be further expanded at the level of the superior olivary complex.