Volkmar Bruns

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The innervation of the cochlea of the greater horseshoe bat was investigated by different methods. The regional densities of the spiral ganglion neurons and of the inner and outer receptors were determined from surface specimens and histological sections. The pattern of the unmyelinated fibers was reconstructed in EM serial sections and the efferent pattern(More)
Subterranean mole rats of the Spalax ehrenbergi superspecies in Israel have a distinctly developed vocal repertoire, presumably compensating together with olfaction for their complete blindness, thus providing an efficient communication system underground. Here we describe the unique organization of the cochlea of Spalax among mammals. The cochlea is(More)
The development of cochlear receptor cells and their supporting elements was studied by means of semi-thin and ultra-thin sections during the first postnatal weeks in the rat. The temporal and spatial patterns of the receptor cell development were investigated between the 4th and 24th days after birth. At approx. ten equidistant positions along the entire(More)
To date our knowledge of the baso-apical distribution of the afferent and efferent nerve fibers innervating the organ of Corti is only fragmentary. This study makes an effort to lay the basis for a comprehensive analysis of cochlear innervation. Using a quantitative electronmicroscopic method, the fiber density of all cochlear fibers along the entire length(More)
Morphometric analysis of the cochlea was performed in wild and laboratory murids: Mus musculus, Apodemus sylvaticus, Rattus rattus, R. norvegicus, NMRI mouse, and Wistar rat. Results are based on light microscopic examination of surface specimens and serial sections and on three-dimensional computer reconstruction. The cochleae have 1.75-2.2 coils. The(More)
Compared to acoustically unspecialized mammals (soricids and murids), the middle ear of subterranean insectivores and rodents (twelve species of six families examined) was clearly distinguished and characterized by many common features: rather round and relatively larger eardrum without a pars flaccida; reduced gonial; loose or no connection between the(More)
The cochlea of the mole rat Cryptomys hottentotus was investigated with physiological and anatomical methods. In order to reveal the place-frequency map of the cochlea, iontophoretic HRP-applications were made in the cochlear nucleus at physiologically characterized locations. Subsequent HRP-transport in auditory nerve fibres and labeling patterns of spiral(More)
above (top) and from the front (bottom). A slit cylinder (2) inside a black wooden box (3) revolves round a tungsten light source (1) and generates a pattern of shadow stripes on a screen (5). The pattern movement is recorded by a photocell (4). Two of these screens are directed each toward one compound eye of the moth so that angular widths of the stripes(More)
The eardrum and the auditory ossicles of the middle ear, and the population of cochlear receptors in subterranean mole-rats of Spalax ehrenbergi complex were qualitatively and quantitatively analyzed. The area of the eardrum was 10.2 (S.D. = 0.9) mm2, that of the stapedial footplate 0.6 (S.D. = 0.07) mm2, the malleus: incus lever ratio was 1.25:1. The(More)