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Caudal
Terms modified by Caudal Selected AbstractsAnalysis of pattern precision shows that Drosophila segmentation develops substantial independence from gradients of maternal gene productsDEVELOPMENTAL DYNAMICS, Issue 11 2006David M. Holloway Abstract We analyze the relation between maternal gradients and segmentation in Drosophila, by quantifying spatial precision in protein patterns. Segmentation is first seen in the striped expression patterns of the pair-rule genes, such as even-skipped (eve). We compare positional precision between Eve and the maternal gradients of Bicoid (Bcd) and Caudal (Cad) proteins, showing that Eve position could be initially specified by the maternal protein concentrations but that these do not have the precision to specify the mature striped pattern of Eve. By using spatial trends, we avoid possible complications in measuring single boundary precision (e.g., gap gene patterns) and can follow how precision changes in time. During nuclear cleavage cycles 13 and 14, we find that Eve becomes increasingly correlated with egg length, whereas Bcd does not. This finding suggests that the change in precision is part of a separation of segmentation from an absolute spatial measure, established by the maternal gradients, to one precise in relative (percent egg length) units. Developmental Dynamics 235:2949,2960, 2006. © 2006 Wiley-Liss, Inc. [source] The moleskin gene product is essential for Caudal-mediated constitutive antifungal Drosomycin gene expression in Drosophila epitheliaINSECT MOLECULAR BIOLOGY, Issue 3 2004S.-H. Han Abstract The homeobox gene, Caudal, encodes the DNA-binding nuclear transcription factor that plays a crucial role during development and innate immune response. The Drosophila homologue of importin-7 (DIM-7), encoded by moleskin, was identified as a Caudal-interacting molecule during yeast two-hybrid screening. Both mutation of the minimal region of Caudal responsible for moleskin binding and RNA interference (RNAi) of moleskin dramatically inhibited the Caudal nuclear localization. Furthermore, Caudal-mediated constitutive expression of antifungal Drosomycin gene was severely affected in the moleskin- RNAi flies, showing a local Drosomycin expression pattern indistinguishable from that of the Caudal- RNAi flies. These in vivo data suggest that DIM-7 mediates Caudal nuclear localization, which is important for the proper Caudal function necessary for regulating innate immune genes in Drosophila. [source] Macroscopic Anatomy of the Great Vessels and Structures Associated with the Heart of the Ringed Seal (Pusa hispida)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2009H. Smodlaka Summary The ringed seal [Pusa (Phoca) hispida], as well as other seals, exhibits unique anatomical properties when compared to its terrestrial counterparts. In the ringed seal, the most conspicuous marine adaptation is the aortic bulb. This large dilatation of the ascending aorta is comparable to that found in other seal species and marine mammals. The branches of the ascending aorta (brachiocephalic trunk, left common carotid artery and left subclavian artery) are similar to those of higher primates and man. The peculiarities of the venous system are: three pulmonary veins, a pericardial venous plexus, a caval sphincter, a hepatic sinus with paired caudal vena cavae and a large extradural venous plexus. Generally, three common pulmonary veins (right, left and caudal) empty into the left atrium. The pericardial venous plexus lies deep to the mediastinal pericardial pleura (pleura pericardica) on the auricular (ventral) surface of the heart. The caval sphincter surrounds the caudal vena cava as it passes through the diaphragm. Caudal to the diaphragm, the vena cava is dilated (the hepatic sinus), and near the cranial extremity of the kidneys, it becomes biphid. The azygos vein is formed from the union of the right and left azygos veins at the level of the 5th thoracic vertebra. Cardiovascular physiological studies show some of these anatomical variations, especially of the venous system and the ascending aorta, to be modifications for diving. This investigation documents the large blood vessels associated with the heart and related structures in the ringed seal. [source] Motor units in cranial and caudal regions of the upper trapezius muscle have different discharge rates during brief static contractionsACTA PHYSIOLOGICA, Issue 4 2008D. Falla Abstract Aim:, To compare the discharge patterns of motor unit populations from different locations within the upper trapezius muscle during brief submaximal constant-force contractions. Methods:, Intramuscular and surface electromyographic (EMG) signals were collected from three sites of the right upper trapezius muscle distributed along the cranial-caudal direction in 11 volunteers during 10 s shoulder abduction at 25% of the maximum voluntary force. Results:, A total of 38 motor units were identified at the cranial location, 36 from the middle location and 17 from the caudal location. Initial discharge rate was greatest at the caudal location (P < 0.05; mean ± SD, cranial: 16.7 ± 3.6 pps, middle: 16.9 ± 4.0 pps, caudal: 19.2 ± 3.3 pps). Discharge rate decreased during the contraction for the most caudal location only (P < 0.05). Initial estimates of surface EMG root mean square values were highest at the most caudal location (P < 0.05; cranial: 32.3 ± 20.9 ,V, middle: 41.3 ± 21.0 ,V, caudal: 51.6 ± 23.6 ,V). Conclusion:, This study demonstrates non-uniformity of motor unit discharge within the upper trapezius muscle during a brief submaximal constant-force contraction. Location-dependent modulation of discharge rate may reflect spatial dependency in the control of motor units necessary for the development and maintenance of force output. [source] Differential expression of RAR, isoforms in the mouse striatum during development: A gradient of RAR,2 expression along the rostrocaudal axisDEVELOPMENTAL DYNAMICS, Issue 2 2005Wen-Lin Liao Abstract The retinoic acid receptor RAR, is highly expressed in the striatum of the ventral telencephalon. We studied the expression pattern of different RAR, isoforms in the developing mouse striatum by in situ hybridization. We found a differential ontogeny of RAR,2 and RAR,1/3 in embryonic day (E) 13.5 lateral ganglionic eminence (striatal primordium). RAR,2 mRNA was detected primarily in the rostral and ventromedial domains, whereas RAR,1/3 mRNAs were enriched in the caudal and dorsolateral domains. Notably, by E16.5, a prominent decreasing gradient of RAR,2 mRNA was present in the developing striatum along the rostrocaudal axis, i.e., RAR,2 was expressed at higher levels in the rostral than the caudal striatum. No such gradient was found for RAR,1/3 and RAR,3 mRNAs. The rostrocaudal RAR,2 gradient gradually disappeared postnatally and was absent in the adult striatum. The differential expression pattern of RAR, isoforms in the developing striatum may provide an anatomical basis for differential gene regulation by RAR, signaling. Developmental Dynamics 233:584,594, 2005. © 2005 Wiley-Liss, Inc. [source] Light and scanning microscopic studies of integument differentiation in the grass snake Natrix natrix L. (Lepidosauria, Serpentes) during embryogenesisACTA ZOOLOGICA, Issue 1 2009Elwira Swad Abstract We analysed the differentiation of body cover in the grass snake (Natrix natrix L.) over the full length of the embryo's body at each developmental stage. Based on investigations using both light and scanning electron microscopes, we divided the embryonic development of the grass snake integument into four phases. The shape of the epidermal cells changes first on the caudal and ventral parts of the embryo, then gradually towards the rostral and dorsal areas. In stage V on the ventral side of the embryo the gastrosteges are formed from single primordia, but on the dorsal side the epidermis forms the scale primordia in stage VII. This indicates that scalation begins on the ventral body surface, and spreads dorsally. The appearance of melanocytes between the cells of the stratum germinativum in stage VII coincides with changes in embryo colouration. The first dermal melanocytes were detected in stage XI so in this stage the definitive skin pattern is formed. In the same stage the epidermis forms the first embryonic shedding complex and the periderm layer begins to detach in small, individual flakes. This process coincides with rapid growth of the embryos. [source] Development of equine upper airway fluid mechanics model for Thoroughbred racehorsesEQUINE VETERINARY JOURNAL, Issue 3 2008V. RAKESH Summary Reason for performing study: Computational fluid dynamics (CFD) models provide the means to evaluate airflow in the upper airways without requiring in vivo experiments. Hypothesis: The physiological conditions of a Thoroughbred racehorse's upper airway during exercise could be simulated. Methods: Computed tomography scanned images of a 3-year-old intact male Thoroughbred racehorse cadaver were used to simulate in vivo geometry. Airway pressure traces from a live Thoroughbred horse, during exercise was used to set the boundary condition. Fluid-flow equations were solved for turbulent flow in the airway during inspiratory and expiratory phases. The wall pressure turbulent kinetic energy and velocity distributions were studied at different cross-sections along the airway. This provided insight into the general flow pattern and helped identify regions susceptible to dynamic collapse. Results: The airflow velocity and static tracheal pressure were comparable to data of horses exercising on a high-speed treadmill reported in recent literature. The cross-sectional area of the fully dilated rima glottidis was 7% greater than the trachea. During inspiration, the area of highest turbulence (i.e. kinetic energy) was in the larynx, the rostral aspect of the nasopharynx was subjected to the most negative wall pressure and the highest airflow velocity is more caudal on the ventral aspect of the nasopharynx (i.e. the soft palate). During exhalation, the area of highest turbulence was in the rostral and mid-nasopharynx, the maximum positive pressure was observed at the caudal aspect of the soft palate and the highest airflow velocity at the front of the nasopharynx. Conclusions and clinical relevance: In the equine upper airway collapsible area, the floor of the rostral aspect of the nasopharynx is subjected to the most significant collapsing pressure with high average turbulent kinetic during inhalation, which may lead to palatal instability and explain the high prevalence of dorsal displacement of the soft palate (DDSP) in racehorses. Maximal abduction of the arytenoid cartilage may not be needed for optimal performance, since the trachea cross-sectional area is 7% smaller than the rima glottidis. [source] The influence of head and neck position on kinematics of the back in riding horses at the walk and trotEQUINE VETERINARY JOURNAL, Issue 1 2005M. RHODIN Summary Reasons for performing study: A common opinion among riders and in the literature is that the positioning of the head and neck influences the back of the horse, but this has not yet been measured objectively. Objectives: To evaluate the effect of head and neck position on the kinematics of the back in riding horses. Methods: Eight Warmblood riding horses in regular work were studied on a treadmill at walk and trot with the head and neck in 3 different predetermined positions achieved by side reins attached to the bit and to an anticast roller. The 3-dimensional movement of the thoracolumbar spine was measured from the position of skin-fixed markers recorded by infrared videocameras. Results: Head and neck position influenced the movements of the back, especially at the walk. When the head was fixed in a high position at the walk, the flexion-extension movement and lateral bending of the lumbar back, as well as the axial rotation, were significantly reduced when compared to movements with the head free or in a low position. At walk, head and neck position also significantly influenced stride length, which was shortest with the head in a high position. At trot, the stride length was independent of head position. Conclusions: Restricting and restraining the position and movement of the head and neck alters the movement of the back and stride characteristics. With the head and neck in a high position stride length and flexion and extension of the caudal back were significantly reduced. Potential relevance: Use of side reins in training and rehabilitation programmes should be used with an understanding of the possible effects on the horse's back. [source] M cells and associated lymphoid tissue of the equine nasopharyngeal tonsilEQUINE VETERINARY JOURNAL, Issue 3 2001P. KUMAR Summary The aim of this study was to characterise the morphological and histochemical features of equine nasopharyngeal tonsillar tissue. Nasal and oropharyngeal tonsillar tissue has been described as the gatekeeper to mucosal immunity because of its strategic location at the entrance to the respiratory and alimentary tracts. A combination of light, scanning and transmission electron microscopy has revealed the presence of follicle-associated epithelium (FAE) overlying lymphoid tissue of the equine nasopharyngeal tonsil caudal to the pharyngeal opening of the guttural pouch. Membranous microvillus (M) cells were identified in the FAE on the basis of short microvilli, an intimate association with lymphocytes, cytoplasmic vimentin filaments and epitopes on the apical surface reactive with lectin GS I-B4 specific for ,-linked galactose. CD4-positive lymphocytes were scattered throughout the lamina propria mucosae as well as forming dense aggregates in the subepithelial part. The central follicular area was heavily populated with B lymphocytes and the dome and parafollicular areas contained both CD4- and CD8-positive lymphocytes. CD8-positive lymphocytes were also present in the epithelium and, together with B lymphocytes, in small numbers in the lamina propria mucosae. These observations indicate that the nasopharyngeal tonsil is potentially an important mucosal immune induction site in the horse and an appropriate target forintranasally administered vaccines. [source] Equine dental disease Part 4: a long-term study of 400 cases: apical infections of cheek teethEQUINE VETERINARY JOURNAL, Issue 3 2000P. M. Dixon Summary Of 400 horses referred because of equine dental disease, 162 suffered from primary apical infections of their cheek teeth (CT), including 92 with maxillary CT infections and 70 with mandibular CT infections. Maxillary swellings and sinus tracts were more common (82 and 26% incidence, respectively) with infections of the rostral 3 maxillary CT, than with infections of the caudal 3 maxillary CT(39 and 5% incidence, respectively). Nasal discharge was more commonly present with caudal (95%) than rostral (23%) maxillary CT infections. Mandibular CT apical infections commonly had mandibular swellings (91%) and mandibular sinus tracts (59%) and these infections were closely related to eruption of the affected CT. A variety of treatments, including medical treatment, apical curettage, repulsion and oral extraction of affected teeth were utilised in these cases, with oral extraction appearing to be most satisfactory. Infections of caudal maxillary CT with a secondary paranasal sinusitis were most refractory to treatment, with a complete response to the initial treatment achieved in just 33% of these cases. Most other cases responded fully to their initial treatment. The long-term response to treatment was good in most cases. [source] Altered volume and hemispheric asymmetry of the superficial cortical layers in the schizophrenia planum temporaleEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2009John F. Smiley Abstract In vivo structural MRI studies in schizophrenia auditory cerebral cortex have reported smaller volumes and, less consistently, have reported altered hemispheric asymmetry of volumes. We used autopsy brains from 19 schizophrenia and 18 nonpsychiatric male subjects to measure the volume asymmetry of the planum temporal (PT). We then used the most recently autopsied 11 schizophrenia and 10 nonpsychiatric brains to measure the widths and fractional volumes of the upper (I,III) and lower (IV,VI) layers. Measurements of whole PT gray matter volumes did not show significant changes in schizophrenia. Nevertheless, laminar volume measurements revealed that the upper layers of the PT comprise a smaller fraction of the total cortex in schizophrenia than in nonpsychiatric brains. Subdivision of the PT showed that this change was especially prominent caudally, beyond Heschl's gyrus, whereas similar but less pronounced changes were found in the rostral PT and Heschl's gyrus. Complementary measures of laminar widths showed that the altered fractional volume in the caudal left PT was due mainly to ,8% thinner upper layers. However, the caudal right PT had a different profile, with thicker lower layers and comparatively unchanged upper layers. Thus, in the present study, laminar measurements provided a more sensitive method for detecting changes than measurement of whole PT volumes. Besides findings in schizophrenia, our cortical width measurements revealed normal hemispheric asymmetries consistent with previous reports. In schizophrenia, the thinner upper layers of the caudal PT suggest disrupted corticocortical processing, possibly affecting the multisensory integration and phonetic processing of this region. [source] Dissociable effects of cocaine-seeking behavior following D1 receptor activation and blockade within the caudal and rostral basolateral amygdala in ratsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2009Yasmin Mashhoon Abstract Research with dopamine D1 receptor antagonists or neuronal inactivating agents suggests that there is dissociable regulation of cocaine-seeking behavior by the rostral and caudal basolateral amygdala. In the present study, discrete infusions of the D1 receptor agonist SKF 81297 (0.0,0.8 ,g per side) were compared with those of the D1 receptor antagonist SCH 23390 (0.0,2.0 ,g per side) to demonstrate directly the importance of D1 receptor mechanisms within the rostral and caudal basolateral amygdala for their functional heterogeneity in regulating cocaine-seeking behavior. Under a second-order schedule, cocaine-seeking behavior was studied during maintenance (cocaine and cocaine cues present) and reinstatement (only cocaine cues present). Food-maintained responding was used to examine the specificity of maximal behaviorally effective doses of SKF 81297 and SCH 23390. The results demonstrated that the D1 agonist (0.4 or 0.8 ,g) increased and the D1 antagonist (1.0 ,g) decreased cocaine-seeking behavior during maintenance when infused into the caudal but not the rostral basolateral amygdala. Cocaine intake was not affected by the agonist, and was decreased by the antagonist. During reinstatement, the D1 agonist (0.4 ,g) increased and the D1 antagonist (1.0 ,g) decreased cocaine-seeking behavior when infused into the rostral but not the caudal basolateral amygdala. In tests for behavioral specificity, the above effective doses of SKF 81297 and SCH 23390 used in self-administration experiments did not alter food-maintained responding. However, the 2.0-,g dose of SCH 23390 suppressed drug-maintained and food-maintained responding after infusion into both subregions. Collectively, these findings indicate dissociable sensitivity to D1 receptor ligands within the caudal and rostral basolateral amygdala for altering cocaine-seeking behavior under different conditions that model phases of addiction. [source] Genetic mapping of Foxb1-cell lineage shows migration from caudal diencephalon to telencephalon and lateral hypothalamusEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2008Tianyu Zhao Abstract The hypothalamus is a brain region with vital functions, and alterations in its development can cause human disease. However, we still do not have a complete description of how this complex structure is put together during embryonic and early postnatal stages. Radially oriented, outside-in migration of cells is prevalent in the developing hypothalamus. In spite of this, cell contingents from outside the hypothalamus as well as tangential hypothalamic migrations also have an important role. Here we study migrations in the hypothalamic primordium by genetically labeling the Foxb1 diencephalic lineage. Foxb1 is a transcription factor gene expressed in the neuroepithelium of the developing neural tube with a rostral expression boundary between caudal and rostral diencephalon, and therefore appropriate for marking migrations from caudal levels into the hypothalamus. We have found a large, longitudinally oriented migration stream apparently originating in the thalamic region and following an axonal bundle to end in the anterior portion of the lateral hypothalamic area. Additionally, we have mapped a specific expansion of the neuroepithelium into the rostral diencephalon. The expanded neuroepithelium generates abundant neurons for the medial hypothalamus at the tuberal level. Finally, we have uncovered novel diencephalon-to-telencephalon migrations into septum, piriform cortex and amygdala. [source] Oxytocin injected into the ventral tegmental area induces penile erection and increases extracellular dopamine in the nucleus accumbens and paraventricular nucleus of the hypothalamus of male ratsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2007Maria Rosaria Melis Abstract The neuropeptide oxytocin (20,100 ng), induces penile erection when injected unilaterally into the caudal but not rostral mesencephalic ventral tegmental area (VTA) of male Sprague,Dawley rats. Such pro-erectile effect started 30 min after treatment and was abolished by the prior injection of d(CH2)5Tyr(Me)2 -Orn8 -vasotocin (1 µg), an oxytocin receptor antagonist injected into the same caudal ventral tegmental area or of haloperidol (1 µg), a dopamine receptor antagonist, injected either into the nucleus accumbens shell (NAs) or into the paraventricular nucleus of the hypothalamus (PVN) ipsilateral to the injected ventral tegmental area. Penile erection was seen 15 min after the occurrence of, or concomitantly to, an increase in extracellular dopamine and its metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) in the dialysate obtained from the nucleus accumbens or the paraventricular nucleus, which was also abolished by d(CH2)5Tyr(Me)2 -Orn8 -vasotocin (1 µg), injected into the ventral tegmental area before oxytocin. In the caudal ventral tegmental area oxytocin-containing axons/fibres (originating from the paraventricular nucleus) appeared to closely contact cell bodies of mesolimbic dopaminergic neurons retrogradely labelled with Fluorogold injected into the nucleus accumbens shell, suggesting that oxytocin effects are mediated by the activation of mesolimbic dopaminergic neurons, followed in turn by that of incerto-hypothalamic dopaminergic neurons impinging on oxytocinergic neurons mediating penile erection. As the stimulation of paraventricular dopamine receptors not only induces penile erection, but also increases mesolimbic dopamine neurotransmission by activating oxytocinergic neurons, these results provide further support for the existence of a neural circuit in which dopamine and oxytocin influence both the consummatory and motivational/rewarding aspects of sexual behaviour. [source] Eph/ephrin expression in the adult rat visual system following localized retinal lesions: localized and transneuronal up-regulation in the retina and superior colliculusEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2005J. Rodger Abstract Following unilateral optic nerve section in adult PVG hooded rat, the axon guidance cue ephrin-A2 is up-regulated in caudal but not rostral superior colliculus (SC) and the EphA5 receptor is down-regulated in axotomised retinal ganglion cells (RGCs). Changes occur bilaterally despite the retino-collicular projection being mostly crossed. Here we investigate the dynamics of Eph/ephrin expression using in situ hybridization and semi-quantitative immunohistochemistry after localized retinal lesions. Unilateral krypton laser lesions to dorso-nasal retina ablated contralaterally projecting RGCs (DN group); ventro-temporal lesions ablated contralaterally and ipsilaterally projecting RGCs (VT group). Lesions of the entire retina served as controls (Total group). Results are compared to normal animals in which tectal ephrin-A2 and retinal EphA5 are expressed, respectively, as shallow ascending rostro-caudal and naso-temporal gradients. In both SCs of DN and Total groups, tectal ephrin-A2 was up-regulated caudally; in the VT group, expression remained normal bilaterally. Unilateral collicular ablation indicated that bilateral changes in ephrin-A2 expression are mediated via intercollicular pathways. EphA5 expression in the VT group was elevated in the intact nasal region of experimental retinae. For each experimental group, EphA5 expression was also elevated in nasal retina of the opposite eye, resulting in uniform expression across the naso-temporal axis. Up-regulation of ephrin-A2 in caudal, but not rostral, SC suggests the enhancement of developmental positional information as a result of injury. Bilateral increases in retinal EphA5 expression demonstrate that signals for up-regulation operate interocularly. The study demonstrates that signals regulating guidance cue expression are both localized and relayed transneuronally. [source] Odorant specificity of three oscillations and the DC signal in the turtle olfactory bulbEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2003Ying-Wan Lam Abstract The odour-induced population response in the in vivo turtle (Terepene sp.) olfactory bulb consists of three oscillatory components (rostral, middle and caudal) that ride on top of a DC signal. In an initial step to determine the functional role of these four signals, we compared the signals elicited by different odorants. Most experiments compared isoamyl acetate and cineole, odorants which have very different maps of input to olfactory bulb glomeruli in the turtle and a different perceptual quality for humans. We found substantial differences in the response to the two odours in the rise-time of the DC signal and in the latency of the middle oscillation. The rate of rise for cineole was twice as fast as that for isoamyl acetate. Similarly, the latency for the middle oscillation was about twice as long for isoamyl acetate as it was for cineole. On the other hand, a number of characteristics of the signals were not substantially different for the two odorants. These included the latency of the rostral and caudal oscillation, the frequency and envelope of all three oscillations and their locations and spatial extents. A smaller number of experiments were carried out with hexanone and hexanal; the oscillations elicited by these odorants did not appear to be different from those elicited by isoamyl acetate and cineole. Qualitative differences between the oscillations in the turtle and those in two invertebrate phyla suggest that different odour processing strategies may be used. [source] Platypus Pou5f1 reveals the first steps in the evolution of trophectoderm differentiation and pluripotency in mammalsEVOLUTION AND DEVELOPMENT, Issue 6 2008Hitoshi Niwa SUMMARY Uterine nourishment of embryos by the placenta is a key feature of mammals. Although a variety of placenta types exist, they are all derived from the trophectoderm (TE) cell layer of the developing embryo. Egg-laying mammals (platypus and echidnas) are distinguished by a very short intrauterine embryo development, in which a simple placenta forms from TE-like cells. The Pou5f1 gene encodes a class V POU family transcription factor Oct3/4. In mice, Oct3/4 together with the highly conserved caudal -related homeobox transcription factor Cdx2, determines TE fate in pre-implantation development. In contrast to Cdx2, Pou5f1 has only been identified in eutherian mammals and marsupials, whereas, in other vertebrates, pou2 is considered to be the Pou5f1 ortholog. Here, we show that platypus and opossum genomes contain a Pou5f1 and pou2 homolog, pou2-related, indicating that these two genes are paralogues and arose by gene duplication in early mammalian evolution. In a complementation assay, we found that platypus or human Pou5f1, but not opossum or zebrafish pou2, restores self-renewal in Pou5f1 -null mouse ES cells, showing that platypus possess a fully functional Pou5f1 gene. Interestingly, we discovered that parts of one of the conserved regions (CR4) is missing from the platypus Pou5f1 promoter, suggesting that the autoregulation and reciprocal inhibition between Pou5f1 and Cdx2 evolved after the divergence of monotremes and may be linked to the development of more elaborate placental types in marsupial and eutherian mammals. [source] The para-aortic ridge plays a key role in the formation of the renal, adrenal and gonadal vascular systemsJOURNAL OF ANATOMY, Issue 6 2010Sumio Isogai Abstract Renal, adrenal, gonadal, ureteral and inferior phrenic arteries vary in their level of origin and in their calibre, number and precise anatomical relationship to other structures. Studies of the origin and early development of these arteries have evoked sharp disputes. The ladder theory of Felix, which states that ,All the mesonephric arteries may persist; from them are formed the phrenic, suprarenal, renal and internal spermatic arteries' has been generally quoted in the anatomical textbooks without rigorous verification for 100 years. In this study, we re-examined this theory by performing micro-injection of dye and resin into rat (Rattus norvegicus) embryos. Our results revealed that most of the mesonephric arteries had degenerated before the metanephros started its ascent. The definitive renal, adrenal, gonadal, ureteral and inferior phrenic arteries appeared as new branches from the gonadal artery and/or directly from the abdominal aorta to the para-aortic ridge. Coincidental to this, the anatomical architecture of the inter-renal vascular cage, which consists of the interlobar and arcuate arteries and their collateral veins, was completed within the developing metanephros. We demonstrated that the delicate renal vascular cage switched from the primary renal artery to the definitive renal artery and that the route of venous drainage changed from the posterior cardinal vein to the inferior (caudal) vena cava. [source] Development of the pelvis and posterior part of the vertebral column in the AnuraJOURNAL OF ANATOMY, Issue 1 2005Hana Ro, ková Abstract The anuran pelvic girdle is unique among all amphibians in that its acetabular portion is located far posterior to the sacrum, lateral to the postsacral (= caudal) vertebral column, which is reduced to a single rod-like element called the urostyle. This situation in the adult is strikingly different not only from that in ancestral temnospondyls but also in other modern amphibians. Because there is no fossil that would document this evolutionary anatomical modification except for Triadobatrachus, the only data may be inferred from development in modern anurans. We chose seven anuran species (belonging to the genera Discoglossus, Bombina, Pelobates, Bufo, Rana and Xenopus), representing the principal locomotory types (saltation, swimming, crawling and burrowing). Development of the pelvic girdle was studied on cleared and stained whole mounts and partly on serial histological sections. The basic developmental pattern was similar in all species: the pelvis on both sides develops from two centres (puboischiadic and iliac, respectively). The ilium then extends vertically towards the sacral vertebra and later rotates posteriorly so that ultimately the acetabulum is lateral to the tail (= urostyle). Only minor deviations from this pattern were found, mainly associated with differences in water and terrestrial dwelling. [source] Hyoid apparatus and pharynx in the lion (Panthera leo), jaguar (Panthera onca), tiger (Panthera tigris), cheetah (Acinonyx jubatus) and domestic cat (Felis silvestris f. catus)JOURNAL OF ANATOMY, Issue 3 2002G. E. Weissengruber Abstract Structures of the hyoid apparatus, the pharynx and their topographical positions in the lion, tiger, jaguar, cheetah and domestic cat were described in order to determine morphological differences between species or subfamilies of the Felidae. In the lion, tiger and jaguar (species of the subfamily Pantherinae) the Epihyoideum is an elastic ligament lying between the lateral pharyngeal muscles and the Musculus (M.) thyroglossus rather than a bony element like in the cheetah or the domestic cat. The M. thyroglossus was only present in the species of the Pantherinae studied. In the lion and the jaguar the Thyrohyoideum and the thyroid cartilage are connected by an elastic ligament, whereas in the tiger there is a synovial articulation. In adult individuals of the lion, tiger and jaguar the ventral end of the tympanohyal cartilage is rotated and therefore the ventral end of the attached Stylohyoideum lies caudal to the Tympanohyoideum and the cranial base. In newborn jaguars the Apparatus hyoideus shows a similar topographical position as in adult cheetahs or domestic cats. In adult Pantherinae, the Basihyoideum and the attached larynx occupy a descended position: they are situated near the cranial thoracic aperture, the pharyngeal wall and the soft palate are caudally elongated accordingly. In the Pantherinae examined the caudal end of the soft palate lies dorsal to the glottis. Differences in these morphological features between the subfamilies of the Felidae have an influence on specific structural characters of their vocalizations. [source] Medullary motor neurones associated with drinking behaviour of Japanese eelsJOURNAL OF FISH BIOLOGY, Issue 1 2003T. Mukuda A fluorescent dye, Evans blue (EB), was injected into the following seven drinking-associated muscles of the Japanese eel Anguilla japonica: the sternohyoid, third branchial, fourth branchial, opercular, pharyngeal, upper oesophageal sphincter and oesophageal body muscles. The sternohyoid muscle promotes ,ingestion', and the remaining muscles contribute to ,swallowing'. All neurones stained by EB were located ipsilaterally in the caudal medulla oblongata (MO) of the Japanese eel. Neurones projecting into the sternohyoid muscle were identified as those in the spino-occipital motor nucleus (NSO), and neurones projecting into the remaining muscles as those in the glossopharyngeal,vagal motor complex (GVC). Within the GVC, the neuronal arrangement was topological, and hence, ,swallowing' will be completed if the GVC neurones ,fire' progressively from rostral to caudal. These neurones in the NSO and GVC may use acetylcholine (ACh) as a neurotransmitter, as the EB-positive neurones in both nuclei were immunoreactive against anticholine acetyltransferase (anti-ChAT) antibody. Besides the MO, some somata in a ganglion of the vagal nerve were also stained by EB injected into the pharyngeal, the upper oesophageal sphincter and the oesophageal body muscles. The localization and the shape of the somata suggest that they are sensory neurones. These sensory neurones were not ChAT-immunoreactive. Combining these results, based on a model for ,swallowing' in mammals, a plausible model for central organization of ,drinking' in the Japanese eel is proposed, which suggests that ,drinking' in the fishes is regulated by the neuronal circuit for ,swallowing' in mammals. [source] Regional caudal blockade in a pediatric patient affected by the Joubert syndromeACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2009D. Galante No abstract is available for this article. [source] Ricochet of a Bullet in the Spinal Canal: A Case Report and Review of the Literature on Bullet MigrationJOURNAL OF FORENSIC SCIENCES, Issue 5 2010Audrey Farrugia M.D. Abstract:, Ricochet of a bullet in the spinal canal is well known by neurosurgeons but relatively not a common event in usual medico-legal autopsy practice. This article presents a homicide case of a penetrating gunshot injury of the lumbar spine through the T12-L1 intervertebral foramen with active movement of the projectile within the spinal canal to the L5-S1 level. This case illustrates a bullet intradural and intramedullary active movement because of a ricochet of the body of T12 with active redirection of the path. In the current literature, different types of migration in caudal or cranial direction, intradural, or intramedullary are reported. If spontaneous migration of T10 to S1 seems to be more frequent, some authors reported a C1 to S2 migration. Such migration could be asymptomatic or induce neurological impairment. The medico-legal consequences of these migrations within the spinal canal are described. [source] A study of juvenile rat spinal cord injuryJOURNAL OF NEUROCHEMISTRY, Issue 2002J. M. Wingrave Greater than 5% of all spinal cord injuries (SCI) in the US occur in people younger than 16, although a minority, children will require extended attention during their lifetime. While facing increased mortality in the initial 24 h after trauma, children with incomplete injuries seem to have a greater capacity for recovery of function compared to adults suggesting that there is a difference in injury tolerance in the young over the adult. Knowledge of the factors involved in this difference would not only increase understanding of SCI, but also potentiate new avenues for SCI treatment. Yet there has not been a model for the study of youth SCI. For these reasons, we developed a model of SCI in juvenile rats equivalent to an adult injury of 25 g cm force (GCF). To do so, we recorded spinal cord masses of Sprague,Dawley rats at 21, 30, 45, and 60 days of age, compared them to adult cord masses, and assembled a conversion factor that provides youth injuries comparable to adult. To investigate the pathophysiology in juvenile SCI, two cord segments, 1 cm long, were removed from animals 24 h following injury. One segment was centered at the impact site, the other immediately caudal. After homogenization, the samples were assayed by Western blot analysis for calpain content and degradation of 68K Neuro-Filament Protein (68K NFP), a neuronal structural protein. mCalpain expression, a neutral protease previously implicated in secondary SCI, was reduced in juvenile animals relative to adult cohorts. The degradation of 68K NFP was also found to be reduced in juvenile animals. From these analyses, it seems plausible that calpain expression and pathogenic activity is abated in the setting of young rat SCI. Acknowledgements:, Supported by grants from NIH-NINDS. [source] Postinjury estrogen treatment of chronic spinal cord injury improves locomotor function in ratsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 8 2010Eric A. Sribnick Abstract Spinal cord injury (SCI) causes loss of neurological function and, depending on serverity, may cause paralysis. The only recommended pharmacotherapy for the treatment of SCI is high-dose methylprednisolone, and its use is controversial. We have previously shown that estrogen treatment attenuated cell death, axonal and myelin damage, calpain and caspase activities, and inflammation in acute SCI. The aim of this study was to examine whether posttreatment of SCI with estrogen would improve locomotor function by protecting cells and axons and reducing inflammation during the chronic phase following injury. Moderately severe injury (40 g · cm force) was induced in male Sprague-Dawley rats following laminectomy at T10. Three groups of animals were used: sham (laminectomy only), vehicle (dimethyl sulfoxide; DMSO)-treated injury group, and estrogen-treated injury group. Animals were treated with 4 mg/kg estrogen at 15 min and 24 hr postnjury, followed by 2 mg/kg estrogen daily for the next 5 days. After treatment, animals were sacrificed at the end of 6 weeks following injury, and 1-cm segments of spinal cord (lesion, rostral to lesion, and caudal to lesion) were removed for biochemical analyses. Estrogen treatment reduced COX-2 activity, blocked nuclear factor-,B translocation, prevented glial reactivity, attenuated neuron death, inhibited activation and activity of calpain and caspase-3, decreased axonal damage, reduced myelin loss in the lesion and penumbra, and improved locomotor function compared with vehicle-treated animals. These findings suggest that estrogen may be useful as a promising therapeutic agent for prevention of damage and improvement of locomotor function in chronic SCI. © 2010 Wiley-Liss, Inc. [source] Temporal and spatial profiles of cell loss after spinal cord injury: Reduction by a metalloporphyrinJOURNAL OF NEUROSCIENCE RESEARCH, Issue 10 2007Xiang Ling Abstract This study presents quantitative temporal and spatial profiles of neuronal loss and apoptosis following a contusion spinal cord injury (50 g · cm). The profiles were evaluated by counting the cresol violet,stained surviving cells and the total number of TUNEL-positive cells and of TUNEL-positive neurons in sections 0, 4 mm from the epicenter and 1, 6, 12, 24, 48, and 72 hr and 1 week postinjury. We demonstrated that neurons continue to disappear over 1 week postinjury and that neuronal loss shifts to areas longer distances from the epicenter over time. TUNEL-positive cells in both gray and white matter appeared after 6 hr, gradually increased to a peak level after 48 hr, and declined by 72 hr postinjury. TUNEL-positive neurons peaked earlier and were present for 1 week, although the total number of neurons was reduced significantly by the end of the week. The neuronal loss and apoptosis were partially prevented by a metalloporphyrin [Mn(III) tetrakis (4-benzoic acid) porphyrin (MnTBAP)]. We demonstrated that MnTBAP (10 and 50 mg/kg, given intraperitoneally) significantly reduced neuronal death in the sections 1,2.5 mm rostral and 1 mm caudal from the epicenter compared with that in the vehicle-treated group, suggesting MnTBAP is more effective in the sections rostral than in those caudal to the epicenter. MnTBAP (10 mg/kg) significantly reduced the number of TUNEL-positive neurons in the sections 1 mm caudal from the epicenter. Our profiles provide a database for pharmacological intervention, and our results on MnTBAP treatment support an important role for antioxidant therapy in spinal cord injury. © 2007 Wiley-Liss, Inc. [source] Neutralization of the chemokine CXCL10 reduces apoptosis and increases axon sprouting after spinal cord injuryJOURNAL OF NEUROSCIENCE RESEARCH, Issue 4 2006Janette Glaser Abstract Spinal cord injury (SCI) is followed by a secondary degenerative process that includes cell death. We have previously demonstrated that the chemokine CXCL10 is up-regulated following SCI and plays a critical role in T-lymphocyte recruitment to sites of injury and inhibition of angiogenesis; antibody-mediated functional blockade of CXCL10 reduced inflammation while enhancing angiogenesis. We hypothesized, based on these findings, that the injury environment established by anti-CXCL10 antibody treatment would support greater survival of neurons and enhance axon sprouting compared with the untreated, injured spinal cord. Here, we document gene array and histopathological data to support our hypothesis. Gene array analysis of treated and untreated tissue from spinal cord-injured animals revealed eight apoptosis-related genes with significant expression changes at 3 days postinjury. In support of these data, quantification of TUNEL-positive cells at 3 days postinjury indicated a 75% reduction in the number of dying cells in treated animals compared with untreated animals. Gene array analysis of treated and untreated tissue also revealed six central nervous system growth-related genes with significant expression changes in the brainstem at 14 days postinjury. In support of these data, quantification of anterograde-labeled corticospinal tract fibers indicated a 60,70% increase in axon sprouting caudal to the injury site in treated animals compared with untreated animals. These findings indicate that anti-CXCL10 antibody treatment provides an environment that reduces apoptosis and increases axon sprouting following injury to the adult spinal cord. © 2006 Wiley-Liss, Inc. [source] A subpopulation of nervus terminalis neurons projects to the olfactory mucosa in Xenopus laevisJOURNAL OF NEUROSCIENCE RESEARCH, Issue 1 2001Joseph M. Koza Abstract Biocytin application to the normal or zinc sulfate-treated nasal cavity of Xenopus laevis was used to trace retrogradely neurons associated with the terminal nerve (TN). Immunocytochemistry was conducted to identify the relationship of gonadotropin-releasing hormone-immunoreactive (GnRH-ir) TN neurons with biocytin-labeled neurons. Neurons that accumulated biocytin were located in olfactory nerve fascicles close to the olfactory mucosa lining the caudal, medial, and rostral walls of the principal cavity. GnRH-ir fibers were observed only in the olfactory nerve fascicle projecting to the rostral edge of the principal cavity. In addition, GnRH-ir fibers did not contact biocytin-labeled TN neurons. We hypothesize that these two classes of neurons represent separate components of the TN. J. Neurosci. Res. 66:8,15, 2001. © 2001 Wiley-Liss, Inc. [source] Differential localization of carbachol- and bicuculline-sensitive pontine sites for eliciting REM sleep-like effects in anesthetized ratsJOURNAL OF SLEEP RESEARCH, Issue 1 2009VICTOR B. FENIK Summary Carbachol, a cholinergic agonist, and GABAA receptor antagonists injected into the pontine dorsomedial reticular formation can trigger rapid eye movement (REM) sleep-like state. Data suggest that GABAergic and cholinergic effects interact to produce this effect but the sites where this occurs have not been delineated. In urethane-anesthetized rats, in which carbachol effectively elicits REM sleep-like episodes (REMSLE), we tested the ability of 10 nL microinjections of carbachol (10 mm) and bicuculline (0.5 or 2 mm) to elicit REMSLE at 47 sites located within the dorsal pontine reticular formation at the levels -8.00 to -10.80 from bregma (B) (Paxinos and Watson, The Rat Brain in Stereotaxic Coordinates, Academic Press, San Diego, 1997). At rostral levels, most carbachol and some bicuculline injections elicited REMSLE with latencies that gradually decreased from 242 to 12 s for carbachol and from 908 to 38 s for bicuculline for more caudal injection sites. As the latencies decreased, the durations of bicuculline-elicited REMSLE increased from 104 s to over 38 min, and the effect was dose dependent, whereas the duration of carbachol-elicited REMSLE changed little (104,354 s). Plots of REMSLE latency versus the antero-posterior coordinates revealed that both drugs were maximally effective near B-8.80. At levels caudal to B-8.80, carbachol was effective at few sites, whereas bicuculline-elicited REMSLE to at least B-9.30 level. Thus, the bicuculline-sensitive sites extended further caudally than those for carbachol and antagonism of GABAA receptors both triggered REMSLE and controlled their duration, whereas carbachol effects on REMSLE duration were small or limited by its concurrent REMSLE-opposing actions. [source] A simplified technique for diagnostic and surgical arthroscopy of the shoulder joint in the dogJOURNAL OF SMALL ANIMAL PRACTICE, Issue 1 2002F. M. Martini A modified technique is presented for surgical and diagnostic arthroscopy of the shoulder joint in the dog. The technique involves access to the joint through two points only; one was created in place of the drainage needle-cannula, which was replaced with a portal, while the second was located more caudally compared with previous techniques. Using a changing guide rod system the two portals are completely interchangeable in order to perform easier arthroscopic surgery either in the cranial or caudal aspect of the joint. The presence of only one portal caudal to the lateral collateral ligament allows more freedom of movement and avoids interference between the arthroscope and the instruments. The modified procedure was performed on 33 joints affected by osteochondritis dissecans or tenoligament diseases and facilitated straightforward diagnostic examinations, and simple and rapid surgical procedures. [source] | ||||||||||||||||||||||||||||||||||