Quantitative Morphological Study Research Articles

Condition of epidermis and epidermal-dermal skin connection in patients with psoriasis and essential hypertension

Background. Issues of lesion pathomorphogenesis in epithelial component of the skin in patients with psoriasis and hypertension on the background of the skin involutive changes requires clarification and further development. The aim of research is to determine the structural damage to epidermis in psoriasis patients depending on the presence or absence of hypertension. Materials and methods. In 60 patients skin biopsies were studied using light-optical microscopy. Quantitative morphological study was conducted using software package ImageJ 1,47v and common principles of morphometric analysis. Results. Morphological examination of the skin condition in elderly patients of the control group revealed typical involutive changes in the epidermis. In particular, the epidermis on the surface of smoothed papillae was unevenly thinned. The maximum total thickness of basal, spinous and granular layers was 41,7 ± 5,1 µm, the minimum – 26,3 ± 3,6 µm. In the loci of thinning (above the tips of papillae) cell ratio in layers of epidermis remained without pathological features. Conclusion. It was found that the morphological substrate of epidermal damage in patients with psoriasis and hypertension is a complex of local violations of the epithelial structure of the skin component: perifocal hyperplasia and degeneration of keratinocytes with acantholysis and destruction of the dermal-epidermal connection, including fragmentation of the basement membrane of the epidermis. This triggers the cascade of typical pathomorphological changes which intensity is significantly higher than the skin lesions in psoriasis patients without hypertension. In the active phase of psoriasis presence of hypertension aggravates the degree of local damage of the epidermis, strengthening the development of hyperkeratosis, parakeratosis, papillomatous hyperplasia, extracellular and cytoplasmic edema of epidermocytes, separation and detachment of the epidermis due to extravasations, Munro’s microabscesses, leukocyte infiltration, erythrodiapedesis, and hemorrhage.

Morphological features of the skin microcirculatory bed in patients with psoriasis and essential hypertension.

Background. Many questions about pathomorphogenesis of damage of the skin microcirculatory bed in patients with psoriasis and hypertension on the background of the skin age changes require clarification and further advance. Objective. The aim of research is to determine the damages of the skin microcirculatory bed in psoriasis patients, depending on the presence or absence of hypertension. Methods. In 60 patients with active psoriasis with and without hypertension skin biopsies were studied using light-optical microscopy. In quantitative morphological study the maximum and minimum overall length of basal, spinous and granular layers of the epidermis were explored, numerical density of nuclei and mitotic index of keratinocytes were calculated. Results. It was found that the morphological basis of damages of the skin microcirculatory bed in patients with psoriasis and hypertension is a complex of general vascular changes: hyperproliferation of microvascular wall cells (endothelial cells, pericytes, smooth myocytes) with the development of hyalinosis and elastofibrosis of arterioles, disseminated abuse of angioarchitectonics of arterioles and intrapapillary hemocapillaries. It triggers a cascade of typical pathomorphological changes of significantly higher intensity than the skin lesions in psoriasis patients without hypertension. Conclusion. Comorbid morphogenesis causes dermal damage in patients with psoriasis and hypertension: significant interstitial edema of papillary layer; perifocal leukocyte infiltration, exudation, extravasations, plasmorrhage consisting of dermal papillae; lymphostasis and local extension of lymphatic drainage; erythrocyte sludging, erythrodiapedesis, hemorrhage; strengthening of endothelial dysfunction with activation of vascular-platelet hemostasis.

Nanostructured surfaces investigated by quantitative morphological studies

The morphology of different surfaces has been investigated by atomic force microscopy and quantitatively analyzed in this paper. Two different tools have been employed to this scope: the analysis of the height–height correlation function and the determination of the mean grain size, which have been combined to obtain a complete characterization of the surfaces. Different materials have been analyzed: SiOxNy, InGaN/GaN quantum wells and Si nanowires, grown with different techniques. Notwithstanding the presence of grain-like structures on all the samples analyzed, they present very diverse surface design, underlying that this procedure can be of general use. Our results show that the quantitative analysis of nanostructured surfaces allows us to obtain interesting information, such as grain clustering, from the comparison of the lateral correlation length and the grain size.

Quantitative characterization and comparative study of feather melanosome internal morphology using surface analysis

A successful feather development implies in a precise orchestration of cells in the follicle, which culminates in one of the most complex epidermal structures in nature. Melanocytes contribute to the final structure by delivering melanosomes to the barb and barbule cells. Disturbance to the tissue during the feather growth can damage the final structure. Here, melanosomes seen in an unusual outgrowth on the barb cortex of a flight feather are reported and compared to commonly observed melanosomes embedded in the cortex. Transmission Electron Microscopy in scanning-transmission mode (STEM) generated images coupled with secondary electron detection. The two classes of melanosomes were registered on images combining transmitted and secondary electron signals. Image processing allowed surface analyses of roughness and texture of the internal morphology of these organelles. Results showed that the two classes of melanosomes are significantly distinct internally, indicating that different physiological processes up to feather maturation could have occurred. Surface analysis methods are not regularly used in cell biology studies, but here it is shown that it has great potential for microscopic image analysis, which could add robust information to studies of cell biology events.

Morphological Pulmonary Diffusion Capacity for Oxygen of Burmese Pythons (Python molurus): a Comparison of Animals in Healthy Condition and with Different Pulmonary Infections

A qualitative and quantitative morphological study of the pulmonary exchange capacity of healthy and diseased Burmese pythons (Python molurus) was carried out in order to test the hypothesis that the high morphological excess capacity for oxygen exchange in the lungs of these snakes is one of the reasons why pathological processes extend throughout the lung parenchyma and impair major parts of the lungs before clinical signs of respiratory disease become apparent. Twenty-four Burmese pythons (12 healthy and 12 diseased) were included in the study. A stereology-based approach was used to quantify the lung parenchyma using computed tomography. Light microscopy was used to quantify tissue compartments and the respiratory exchange surface, and transmission electron microscopy was used to measure the thickness of the diffusion barrier. The morphological diffusion capacity for oxygen of the lungs and the anatomical diffusion factor were calculated. The calculated anatomical diffusion capacity was compared with published values for oxygen consumption of healthy snakes, and the degree to which the exchange capacity can be obstructed before normal physiological function is impaired was estimated. Heterogeneous pulmonary infections result in graded morphological transformations of pulmonary parenchyma involving lymphocyte migration into the connective tissue and thickening of the septal connective tissue, increasing thickness of the diffusion barrier and increasing transformation of the pulmonary epithelium into a columnar pseudostratified or stratified epithelium. The transformed epithelium developed by hyperplasia of ciliated cells arising from the tip of the faveolar septa and by hyperplasia of type II pneumocytes. These results support the idea that the lungs have a remarkable overcapacity for oxygen consumption and that the development of pulmonary disease continuously reduces the capacity for oxygen consumption. However, due to the overcapacity of the lungs, this reduction does not result in clinical signs and disease can progress unrecognized for an extended period.

A quantitative study of MC3T3-E1 cell adhesion, morphology and biomechanics on chitosan–collagen blend films at single cell level

The interaction between cells and biomaterials plays a key role in cell proliferation and differentiation in tissue engineering. However, a quantitative analysis of those interactions has been less well studied. The objective of this study was to quantitative recapitulate the difference of MC3T3-E1 cell adhesion, morphological and biomechanical properties on chitosan–collagen films in terms of chemical composition. Here, the unbinding force between MC3T3-E1 cell and a series of chitosan–collagen films was probed by a real-time and in situ atomic force microscopy–single cell force spectroscopy (AFM–SCFS). Meanwhile, changes in cell morphology and Young's modulus on different chitosan–collagen films were detected by AFM. The cell area and CCK-8 results showed that cell spreading and proliferation increased with increasing collagen content. AFM observations clearly showed cell height decreased and pseudopod fusion with the collagen content increased. Cell adhesive force increased from 0.76±0.17nN to 1.70±0.19nN. On the contrary, cells Young's modulus, which reflected biophysical changes of cells decreased from 11.94±3.19kPa to 1.81±0.52kPa, respectively. It suggested that stronger cell–substrate interactions benefit cell adhesion, and better cell flexibility improve cell spreading. The findings indicate that cell morphology, adhesive force and Young's modulus are significant affected by various chitosan–collagen substrates. Those methods and quantitative results have guiding significance for investigating the mechanism of chitosan and/or collagen based cell-targeting drug carrier and the preparation of chitosan–collagen composite biomaterials.

Патоморфологическое исследование гиппокампа при церебральном атеросклерозе у лиц второго периода зрелого возраста

The purpose of this research is to study the morphology of the hippocampus in the patients with cerebro-vascular disease with age, sex and somatic types. The study was conducted from autopsy material. The hippocampus male (n=20) and female (n=15) of the patients of the second period of mature age were taken for study. Pathological and anatomical examination showed that all dead people had pathology of brain vessels. Changes specific to the 1 and 2 stages of atherosclerosis were detected in the basilar and middle cerebral arteries. Somatotype was defined with the subsequent calculation of the index by the method of Rees-Eysenck. The morphometric research of right and left hippocampus of the brain has been conducted. The parameters of the hippocampus with the sex were determined. There are presented the results of quantitative and qualitative morphological study of the hippocampus in persons of the second period of adulthood with cerebral arteriosclerosis in various somatotypes. The comparative analysis, of morphometric parameters of the hippocampus of the right and left hemispheres of the human brain, showed, that most significant are the length of the hippocampus width of middle part and width region of legs. On microscopic examination of the hippocampus, the individuals of the second period of mature age, even at the early stages of atherosclerosis of cerebral arteries, are detected dystrophic changes of neurons in the CA1 and CA3 regions, showing their ischemic damage.

Review of Quantitative Study of Rill Morphology on Slope

Morphological development of rill at hillslope formed a microrelief dynamic response system with soil erosion driven by rainfall. To reveal the formation mechanism of this system, scientifically quantification is the key problem. In recent years, domestic and foreign scholars had achieved fruitful results in rill evolution and quantized fields. This paper analysised the existing problems in the present research based on summarizing the current existing methods of rill morphology quantitation, and put forward the research direction in the future.

Nanometer-scale pore fluid distribution and drying damage in preserved clay cores from Belgian clay formations inferred by BIB-cryo-SEM

This contribution reports on the distribution of in situ pore-water in preserved clay cores from Belgium (Boom Clay at HADES URF level and clay from the Pittem Member of the Gent Formation) and identification of typical pore-scale damage induced by drying.BIB–cryo-SEM (Broad Ion beam–cryogenic-SEM) shows that the majority of pores visible at the resolution of SEM (>50nm) does not contain water, suggesting that the water content measured by weight loss is located in clay aggregates, in pores<50nm.Because water-free pores are not expecting in situ clay formation, we conclude that the procedure used to preserve the original clay cores is not fully efficient. Observations of evolution of microstructures before and after drying by sublimation of water point to four types of drying-damages driven by the shrinkage of clay particles. On the one hand, quantification of pore size and pore morphologies before and after drying indicates no significant change in statistical pore characterization, suggesting that quantitative pore morphology studies on a large number of pores performed on dried samples are representative of the preserved core samples. On the other hand, the drying damage observed in this contribution is proposed to be responsible of the changes of fluid flow properties typically measured by other authors on preserved and dried specimens of clays.

Ameliorating Effects of Curcumin and Propolis against the Reproductive Toxicity of Gentamicin in Adult Male Guinea Pigs: Quantitative Analysis and Morphological Study

Infertility is a growing worldwide problem and about half of the causes could be traced in male partner. Aim of the work: the present work aimed to study propolis and curcumin for their potential ameliorative effects on reproductive toxicity induced by gentamicin in guinea pigs from morphological and quantitative aspects. Materials and methods: 36 guinea pigs were used for this study and divided into 6 groups. The first 3 groups were control (normal control, curcumin administered, and propolis administered), the 4th group was the experimental and administered gentamicin at a dose of 5 mg/kg body wt for 10 days, and in the 5th and 6th groups, gentamicin was co-administered with propolis and curcumin at the doses of 50 mg, and 10 mg/kg body wt respectively. The animals were sacrificed and the testes were dissected out from which specimens were obtained. The specimens were processed for light microscopic examinations and quantitative analysis. Blood samples were obtained for assessment of plasma testosterone level. Results: Structurally, in gentamicin treated animals, the seminiferous tubules showed sloughing of the germinal epithelium into lumen where sperms were few. The basement membrane appeared thick, irregular and degenerated. Wide interstitial spaces with few Leydig cells were observed. From the quantitative aspect, the percent of volume density and absolute volume of seminiferous tubules were significantly reduced. Also, the diameter, total length, and total surface area of seminiferous tubules were significantly reduced. The numbers of Sertoli cells, round spermatids and daily sperm production per testis and per gram of testicular tissue were significantly decreased in gentamicin treated guinea pigs. As regard to endocrine part of the testis, the percent of volume density of Leydig cell nuclei, the total number of Leydig cells, and plasma testosterone level were significantly decreased in gentamicin treated guinea pigs. With co-administration of propolis and curcumin, the structure of seminiferous tubules improved and their lumens were full of bundles of sperms. Also, all the parameters of seminiferous tubules and total numbers of Sertoli cells, round spermatids, daily sperm production and Leydig cells were ameliorated significantly as compared to gentamicin treated animals. Also, the testosterone level was improved. Conclusion: It can be concluded that, the gentamicin even at therapeutic dose can have adverse impacts on male reproduction. Administration of propolis or curcumin can ameliorate these effects. So, the patients while treated by gentamicin should be advised to use one of them.

Border extrapolation using fractal attributes in remote sensing images

In management, monitoring and rational use of natural resources the knowledge of precise and updated information is essential. Satellite images have become an attractive option for quantitative data extraction and morphologic studies, assuring a wide coverage without exerting negative environmental influence over the study area. However, the precision of such practice is limited by the spatial resolution of the sensors and the additional processing algorithms. The use of high resolution imagery (i.e., Ikonos) is very expensive for studies involving large geographic areas or requiring long term monitoring, while the use of less expensive or freely available imagery poses a limit in the geographic accuracy and physical precision that may be obtained.We developed a methodology for accurate border estimation that can be used for establishing high quality measurements with low resolution imagery. The method is based on the original theory by Richardson, taking advantage of the fractal nature of geographic features. The area of interest is downsampled at different scales and, at each scale, the border is segmented and measured. Finally, a regression of the dependence of the measured length with respect to scale is computed, which then allows for a precise extrapolation of the expected length at scales much finer than the originally available. The method is tested with both synthetic and satellite imagery, producing accurate results in both cases.

Early-stage microvascular alterations of a new model of controlled cortical traumatic brain injury: 3D morphological analysis using scanning electron microscopy and corrosion casting

This study was performed to study the microvascular changes that occur during the first 12 hours after traumatic brain injury (TBI) using the corrosion casting technique. The authors performed a qualitative and quantitative morphological study of the changes in cerebral vessels at acute (3 hours) and subacute (12 hours) stages after experimental TBI. They used a model of controlled cortical impact (CCI) injury induced by a recently developed electromagnetic device (impactor), focusing their observations mainly on the microvascular alterations responsible for the formation and maintenance of tissue edema and consequent brain swelling during the first hours after TBI. They used corrosion casting, scanning electron microscopy (SEM), light microscopy, and transmission electron microscopy (TEM) to obtain a morphological qualitative map with both 2D and 3D details. Scanning electron microscopy analysis of vascular casts documented in 3 dimensions the typical injuries occurring after a TBI: subdural, subarachnoid, and intraparenchymal hemorrhages, along with alterations of the morphological characteristics and architecture of both medium-sized and capillary vessels, including ectasia of pial vessels, sphincter constrictions at the origin of the perforating vessels, focal swelling of perforating vessels, widening of intercellular junctions, and some indirect evidence of structural impairment of endothelial cells. All of these vascular alterations were confirmed in 2D analyses using light microscopy and TEM. The corrosion casting-SEM technique applied to a CCI experimental model proved to be a reliable method for studying the pathophysiology of the vascular alterations occurring at acute and subacute stages after CCI injury. It was also possible to obtain topographical localization of the vascular and cellular events that usually lead to hyperemia, edema, and brain swelling. Moreover, by applying informatic software to anatomical images it was possible to perform quantification and statistical analysis of the observed events.

Fractal analysis of dendrites morphology using modified Richardson's and box counting method.

Fractal analysis has proven to be a useful tool in analysis of various phenomena in numerous naturel sciences including biology and medicine. It has been widely used in quantitative morphologic studies mainly in calculating the fractal dimension of objects. The fractal dimension describes an object's complexity: it is higher if the object is more complex, that is, its border more rugged, its linear structure more winding, or its space more filled. We use a manual version of Richardson's (ruler-based) method and a most popular computer-based box-counting method applying to the problem of measuring the fractal dimension of dendritic arborization in neurons. We also compare how these methods work with skeletonized vs. unskeletonized binary images. We show that for dendrite arborization, the mean box dimension of unskeletonized images is significantly larger than that of skeletonized images. We also show that the box-counting method is sensitive to an object's orientation, whereas the ruler-based dimension is unaffected by skeletonizing and orientation. We show that the mean fractal dimension measured using the ruler-based method is significantly smaller than that measured using the box-counting method. Whereas the box-counting method requires defined usage that limits its utility for analyzing dendritic arborization, the ruler-based method based on Richardson's model presented here can be used more liberally. Although this method is rather tedious to use manually, an accessible computer-based implementation for the neuroscientist has not yet been made available.

PALEOBIOLOGICAL APPLICATIONS OF THREE-DIMENSIONAL BIOMETRY ON LARGER BENTHIC FORAMINIFERA: A NEW ROUTE OF DISCOVERIES.

Four specimens of larger benthic foraminifera (the Recent Palaeonummulites venosus and Operculina ammonoides, and the phylogenetically related Paleogene Nummulites fabianii and N. fichteli) were investigated by X-ray tomography. The resulting three-dimensional measurements enabled a comprehensive, quantitative study of shell morphology to interpret cell growth without specific shell preparation and/or destruction. After segmentation and extraction of all scanned lumina, the following characters were measured on all chambers of each specimen: chamber volume, septal distance, chamber height, and chamber width. The sequence of chamber lumina follows either a logistic function (Palaeonummulites, Operculina), where the deceleration in growth rate of the latest chambers could mark the onset of reproduction, or it can be modeled by a series of stepwise functions with differing constants (Nummulites). Variations around the growth model are either periodic, following external cycles, or random as expressed by abrupt deviations. Therefore, they may reflect the response of the cell to environmental changes in terms of cyclic changes (e.g., seasonality) or single events (e.g., predator attack). Correlations between chamber volume and the other chamber parameters show that septal distance always matches the sequence in chamber volume and can therefore be used as a proxy for environmental analyses in both growth models. Chamber height and width often remain constant around their function and rarely deviate drastically to accommodate the needed lumen for retaining test size and shape. Chamber width may vary according to chamber volume in involute specimens, whereas both chamber height and width correlate with volume in those tests following an Archimedean spiral. X-ray-tomography shows particular promise in determining which parameters that can be assessed routinely in two dimensions primarily reflect environmental conditions vs. parameters best used for taxonomic identification and for systematic lineage reconstruction.

Exploring the cycle behavior of electrodeposited vanadium oxide electrochemical capacitor electrodes in various aqueous environments

Electrodeposited vanadium oxide has emerged as a potential electrochemical capacitor material due to its attractive initial pseudocapacitive performance. However, it suffers from capacitive degradation upon charge/discharge cycling in aqueous electrolytes. Possible degradation mechanisms, including material dissolution, are discussed. To test these possible mechanisms, an agar gel coating is deposited on the films to reduce mass transport between the electrode/electrolyte interface. The electrochemical cycling behavior of vanadium oxide films with various surface treatments is investigated at different pH. Quantitative compositional analysis and morphological studies provide additional insight into the mechanism responsible for capacitive degradation.

The phylogenetic relationships among infraorders and superfamilies of Diptera based on morphological evidence

Members of the megadiverse insect order Diptera (flies) have successfully colonized all continents and nearly all habitats. There are more than 154 000 described fly species, representing 10–12% of animal species. Elucidating the phylogenetic relationships of such a large component of global biodiversity is challenging, but significant advances have been made in the last few decades. Since Hennig first discussed the monophyly of major groupings, Diptera has attracted much study, but most researchers have used non‐numerical qualitative methods to assess morphological data. More recently, quantitative phylogenetic methods have been used on both morphological and molecular data. All previous quantitative morphological studies addressed narrower phylogenetic problems, often below the suborder or infraorder level. Here we present the first numerical analysis of phylogenetic relationships of the entire order using a comprehensive morphological character matrix. We scored 371 external and internal morphological characters from larvae, pupae and adults for 42 species, representing all infraorders selected from 42 families. Almost all characters were obtained from previous studies but required revision for this ordinal‐level study, with homology assessed beyond their original formulation and across all infraorders. We found significant support for many major clades (including the Diptera, Culicomorpha, Bibionomorpha, Brachycera, Eremoneura, Cyclorrhapha, Schizophora, Calyptratae and Oestroidea) and we summarize the character evidence for these groups. We found low levels of support for relationships between the infraorders of lower Diptera, lower Brachycera and major lineages of lower Cyclorrhapha, and this is consistent with findings from molecular studies. These poorly supported areas of the tree may be due to periods of rapid radiation that left few synapomorphies in surviving lineages.

The effects of particulate ambient air pollution on the murine umbilical cord and its vessels: A quantitative morphological and immunohistochemical study

Previous studies have shown that particulate matter (PM) compromise birth weight and placental morphology. We hypothesized that exposing mice to ambient PM would affect umbilical cord (UC) morphology. To test this, mice were kept in paired open-top exposure chambers at the same location and ambient conditions but, in one chamber, the air was filtered (F) and, in the other, it was not (NF). UCs were analysed stereologically and by immunohistochemistry to localize isoprostane and endothelin receptors. The cords of mice from NF chambers were smaller in volume due to loss of mucoid connective tissue and decrease in volume of collagen. These structural changes and in umbilical vessels were associated with greater volumes of regions immunostained for isoprostane, ETAR and ETBR. Findings indicate that the adverse effects of PM on birth weight may be mediated in part by alterations in UC structure or imbalances in the endogenous regulators of vascular tone and oxidative stress.

WE-C-217BCD-05: A Novel Interpolation Method for the 3D Reconstruction of Cell Structures.

To develop a new interpolation method for accurate 3D reconstruction of cell morphology from laser scanning confocal microscope (LSCM) image data. Current techniques are based on the assumption that pixel intensity or contour shapes of images change linearly in the interpolation direction. Gray-value and position of the pixel in interpolated image slice are obtained through weighted average calculation with gray-values and distances of corresponding pixels in two adjacent original image slices, only information from adjacent image slices is considered, often fail to meet the need of 3D reconstruction for cells because of the complex cell morphology. The new method interpolates cellular organelle contours in polar coordinate system. Coordinate system origin is chosen to be the mass center weighted by pixel intensity instead of conventional geometric center, contour points of the organelle is sampled by their angles first and fitted with uniform cubic B-spline to perform interpolation. For complex organelle structures such as branched nuclei, a special method combining morphological information and corner detection technique based on curvature scale space has been developed to solve the contour division and related problems. New method was applied to confocal images of 130 different cells acquired with an LSCM system (LSM510, Zeiss), sampling step was set as 0.5 μm in longitudinal direction, pixel size in horizontal plane was 0.07 μm and the resolution was 512×512. Marching cubes algorithm was used for 3D reconstruction. Experiments showed that reconstructed 3D images with new method have much smoother and more valid organelle surfaces for both cytoplasm and nucleus than those from conventional methods. The new interpolation method can significantly improve the quality of 3D reconstruction and serve as a valid and effective tool for quantitative study of 3D cell morphology in radiation biology and other areas of life science.*support by NSFC- 81171342. Supported by the National Science Foundation of China (NSFC- 81171342).

Comparative study of 3D morphology and functions on genetically engineered mouse melanoma cells

Quantification of 3D morphology and measurement of cellular functions were performed on the mouse melanoma cell lines of B16F10 to investigate the intriguing problem of structure-function relations in the genetically engineered cells with GPR4 overexpression. Results of 3D analysis of cells in suspension and phase contrast imaging of adherent cells yield consistent evidence that stimulation of the proton-sensing GPR4 receptor in these cells may modify significantly their morphology with diminishing ability to produce membrane protrusions and to migrate. Examination of the 3D parameters of mitochondria provide further insights on the measured variation of the maximal capacity of oxygen consumption rate among the genetically modified cells, indicating that the proton-sensing receptor may regulate cancer cell metabolism with increased mitochondrial surface area. Our study demonstrates clearly the significant benefits of quantitative 3D morphological study in illuminating cellular functions and development of novel morphology based cell assay methods.

Quantitative Characterization of the Filiform Mechanosensory Hair Array on the Cricket Cercus

BackgroundCrickets and other orthopteran insects sense air currents with a pair of abdominal appendages resembling antennae, called cerci. Each cercus in the common house cricket Acheta domesticus is approximately 1 cm long, and is covered with 500 to 750 filiform mechanosensory hairs. The distribution of the hairs on the cerci, as well as the global patterns of their movement vectors, have been characterized semi-quantitatively in studies over the last 40 years, and have been shown to be very stereotypical across different animals in this species. Although the cercal sensory system has been the focus of many studies in the areas of neuroethology, development, biomechanics, sensory function and neural coding, there has not yet been a quantitative study of the functional morphology of the receptor array of this important model system.Methodology/Principal FindingsWe present a quantitative characterization of the structural characteristics and functional morphology of the cercal filiform hair array. We demonstrate that the excitatory direction along each hair's movement plane can be identified by features of its socket that are visible at the light-microscopic level, and that the length of the hair associated with each socket can also be estimated accurately from a structural parameter of the socket. We characterize the length and directionality of all hairs on the basal half of a sample of three cerci, and present statistical analyses of the distributions.Conclusions/SignificanceThe inter-animal variation of several global organizational features is low, consistent with constraints imposed by functional effectiveness and/or developmental processes. Contrary to previous reports, however, we show that the filiform hairs are not re-identifiable in the strict sense.