A Bast-like valve in the pigeon?

The first description of the presence of a utriculo-endolymphatic valve in human fetuses was given by Bast in 1928. Since then this valve-like structure is called Bast’s valve. Its exact function has not yet been established. The general opinion is that it has a protective function by having the possibility to separate the superior endolymphatic compartments of the labyrinth from the inferior compartment. Phylogenetically seen birds are the first vertebrates with a cochlear duct and a distinct inferior and superior part of the labyrinth. A structure in the pigeon inner ear, resembling Bast’s valve in mammals, is described

Human arachnoid granulations Part I: a technique for quantifying area and distribution on the superior surface of the cerebral cortex

<p>Abstract</p> <p>Background</p> <p>The arachnoid granulations (AGs) are herniations of the arachnoid membrane into the dural venous sinuses on the surface of the brain. Previous morphological studies of AGs have been limited in scope and only one has mentioned surface area measurements. The purpose of this study was to investigate the topographic distribution of AGs on the superior surface of the cerebral cortex.</p> <p>Methods</p> <p><it>En face </it>images were taken of the superior surface of 35 formalin-fixed human brains. AGs were manually identified using Adobe Photoshop, with a pixel location containing an AG defined as 'positive'. A set of 25 standard fiducial points was marked on each hemisphere for a total of 50 points on each image. The points were connected on each hemisphere to create a segmented image. A standard template was created for each hemisphere by calculating the average position of the 25 fiducial points from all brains. Each segmented image was mapped to the standard template using a linear transformation. A topographic distribution map was produced by calculating the proportion of AG positive images at each pixel in the standard template. The AG surface area was calculated for each hemisphere and for the total brain superior surface. To adjust for different brain sizes, the proportional involvement of AGs was calculated by dividing the AG area by the total area.</p> <p>Results</p> <p>The total brain average surface area of AGs was 78.53 ± 13.13 mm²(n = 35) and average AG proportional involvement was 57.71 × 10^-4± 7.65 × 10^-4. Regression analysis confirmed the reproducibility of AG identification between independent researchers with r²= 0.97. The surface AGs were localized in the parasagittal planes that coincide with the region of the lateral lacunae.</p> <p>Conclusion</p> <p>The data obtained on the spatial distribution and <it>en face </it>surface area of AGs will be used in an <it>in vitro </it>model of CSF outflow. With an increase in the number of samples, this analysis technique can be used to study the relationship between AG surface area and variables such as age, race and gender.</p

Of all foods bread is the most noble: Carl von Linné (Carl Linneaus) on bread1

Carl von Linné was interested in dietetics, which in his time covered all aspects of a healthy life. As a utilitarian he understood the importance of private economy and paid attention to bread in many of his publications. Two texts, Ceres noverca arctoum and De pane diaetetico, were wholly devoted to bread and bread-making. Linné classified different types of bread, and described their nutritional value and health-related aspects, as well as milling, baking and storing, in detail. While discussing the food habits of social classes Linné accepted as a fact that the peasants and the poor should eat less tasty bread than the rich. The less palatable bread had, however, many nutritional and health advantages. Linné paid much attention to substitutes for grain to be used in times of famine, an important topic in eighteenth century Sweden. He regarded flour made of pine bark or water arum roots as excellent famine food, was enthusiastic about the new plant, maize, but considered potato only as a poor substitute for grain. Linné and his followers praised bread not only as the core component of diet, but also for its versatile role both in health and in disease

Sensory cutaneous papillae in the sea lamprey (Petromyzonmarinus L.) : I. Neuroanatomy and physiology

Molecules present in an animal's environment can indicate the presence of predators,food, or sexual partners and consequently, induce migratory, reproductive, foraging,or escape behaviors. Three sensory systems, the olfactory, gustatory, and solitarychemosensory cell (SCC) systems detect chemical stimuli in vertebrates. While agreat deal of research has focused on the olfactory and gustatory system over theyears, it is only recently that significant attention has been devoted to the SCC sys-tem. The SCCs are microvillous cells that were first discovered on the skin of fish,and later in amphibians, reptiles, and mammals. Lampreys also possess SCCs that areparticularly numerous on cutaneous papillae. However, little is known regarding theirprecise distribution, innervation, and function. Here, we show that sea lampreys(Petromyzon marinus L.) have cutaneous papillae located around the oral disk, nostril,gill pores, and on the dorsal fins and that SCCs are particularly numerous on thesepapillae. Tract-tracing experiments demonstrated that the oral and nasal papillae areinnervated by the trigeminal nerve, the gill pore papillae are innervated by branchialnerves, and the dorsal fin papillae are innervated by spinal nerves. We also character-ized the response profile of gill pore papillae to some chemicals and showed thattrout-derived chemicals, amino acids, and a bile acid produced potent responses.Together with a companion study (Suntres et al., Journal of Comparative Neurology,this issue), our results provide new insights on the function and evolution of the SCCsystem in vertebrates

Degenerative Veränderungen im alternden Innenohr, mit besonderer Berücksichtigung der vasculären Veränderungen, in Flächenpräparaten der menschlichen Cochlea dargestellt

Temporal bones from 150 patients, ranging in age from fetuses and newborn to 97 years, were studied by the technique of microdissection and the use of surface specimens stained with OSO 4 . Hair cell and nerve degeneration were seen in the extreme basal turn of the cochlea even in children. In the fetal cochlea vascularization is very dense, in the newborn and infant somewhat less so. A gradual involution of blood vessels occurs postnatally and continues with maturity and aging. Involution is seen especially in the membranous wall of the cochlea and in the system of spiral vessels of the basilar membrane and vestibular lip. During the first decade the radiating arterioles and the outer spiral vessel in the basal turn are reduced to their adult size. In presbycusis material we observed a marked loss of capillaries and of some of the radiating arterioles in the spiral ligament. Other arterioles had thickened walls. This devascularization was accompanied by atrophy and acellularity of the spiral ligament and atrophy of the stria. Atrophy of the spiral vessels was seen, especially in the lower half of the basal turn. Most of the cochlear blood vessels have clearly distinguishable perivascular spaces. Vessels which had become occluded and disappeared left behind them intervascular strands and/or avascular channels . Such channels were seen to connect the perivascular space of one capillary with that of another, representing the perivascular space of the vessel which had atrophied. The hair cell and nerve degeneration seen in presbycusis may be caused, at least in part, by microangiopathy of this type. Similar vascular changes have been observed in retinal vessels. It is possible that the gradual reduction of blood supply through the disappearance of capillaries occurs in many tissues of the body and plays an important role in the aging process. Mit Hilfe der Oberflächenpräparation wurden von uns 150 menschliche Labyrinthe aller Altersgruppen untersucht. Es wurde eine Haarzellen-und Nervendegeneration schon im Kindesalter beobachtet. Blutgefäße in der Schnecke haben perivasculdre Spalten; Gefäße atrophieren and werden zu „avascular channels”, leeren Spaltrdumen oder Striingen. Bei Presbyakusis fällt neben der Haarzell- and Nervendegeneration in der Basalwindung der Schnecke die Gefäßatrophie im Ligamentum spirale und der Membrana basilaris auf. Dazu kommt noch eine beträchtliche Atrophie des Ligamentum spirale und der Stria vascularis. Bemerkenswert ist, daß die Devascularisation schon im Kindesalter beginnt.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47255/1/405_2004_Article_BF00373313.pd

Bmp4 Is Essential for the Formation of the Vestibular Apparatus that Detects Angular Head Movements

Angular head movements in vertebrates are detected by the three semicircular canals of the inner ear and their associated sensory tissues, the cristae. Bone morphogenetic protein 4 (Bmp4), a member of the Transforming growth factor family (TGF-β), is conservatively expressed in the developing cristae in several species, including zebrafish, frog, chicken, and mouse. Using mouse models in which Bmp4 is conditionally deleted within the inner ear, as well as chicken models in which Bmp signaling is knocked down specifically in the cristae, we show that Bmp4 is essential for the formation of all three cristae and their associated canals. Our results indicate that Bmp4 does not mediate the formation of sensory hair and supporting cells within the cristae by directly regulating genes required for prosensory development in the inner ear such as Serrate1 (Jagged1 in mouse), Fgf10, and Sox2. Instead, Bmp4 most likely mediates crista formation by regulating Lmo4 and Msx1 in the sensory region and Gata3, p75Ngfr, and Lmo4 in the non-sensory region of the crista, the septum cruciatum. In the canals, Bmp2 and Dlx5 are regulated by Bmp4, either directly or indirectly. Mechanisms involved in the formation of sensory organs of the vertebrate inner ear are thought to be analogous to those regulating sensory bristle formation in Drosophila. Our results suggest that, in comparison to sensory bristles, crista formation within the inner ear requires an additional step of sensory and non-sensory fate specification

Vergleichende morphologische und histologische untersuchungen am geruchsorgan der knochenfische

1. Untersucht wurden 18 Knochenfischarten aus 13 Familien.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47539/1/435_2004_Article_BF00429940.pd