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Caudal Part (caudal + part)
Selected AbstractsC1 neurons in the rat rostral ventrolateral medulla differentially express vesicular monoamine transporter 2 in soma and axonal compartmentsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2008C. P. Sevigny Abstract Vesicular monoamine transporter 2 (VMAT2) packages biogenic amines into large dense core and synaptic vesicles for either somatodendritic or synaptic release from neurons of the CNS. Whilst the distribution of VMAT2 has been well characterized in many catecholaminergic cell groups, its localization amongst C1 adrenergic neurons in the medulla has not been examined in detail. Within the rostral ventrolateral medulla (RVLM), C1 neurons are a group of barosensitive, adrenergic neurons. Rostral C1 cells project to the thoracic spinal cord and are considered sympathetic premotor neurons. The majority of caudal C1 cells project rostrally to regions such as the hypothalamus. The present study sought to quantitate the somatodendritic expression of VMAT2 in C1 neurons, and to assess the subcellular distribution of the transporter. Immunoreactivity for VMAT2 occurred in 31% of C1 soma, with a high proportion of these in the caudal part of the RVLM. Retrograde tracing studies revealed that only two of 43 bulbospinal C1 neurons contained faint VMAT2-immunoreactivity, whilst 88 ± 5% of rostrally projecting neurons were VMAT2-positive. A lentivirus, designed to express green fluorescent protein exclusively in noradrenergic and adrenergic neurons, was injected into the RVLM to label C1 neurons. Eighty-three percent of C1 efferents that occurred in close proximity to sympathetic preganglionic neurons within the T3 intermediolateral cell column contained VMAT2-immunoreactivity. These data demonstrate differential distribution of VMAT2 within different subpopulations of C1 neurons and suggest that this might reflect differences in somatodendritic vs. synaptic release of catecholamines. [source] Discharge patterns of neurons in the medial pontobulbar reticular formation during fictive mastication in the rabbitEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2001K.-G. Westberg Abstract In this study, we describe functional characteristics of neurons forming networks generating oral ingestive motor behaviours. Neurons in medial reticular nuclei on the right side of the brainstem between the trigeminal and hypoglossal motor nuclei were recorded in anaesthetized and paralysed rabbits during two types of masticatory-like motor patterns induced by electrical stimulation of the left (contralateral) or right (ipsilateral) cortical masticatory areas. Sixty-seven neurons in nucleus reticularis pontis caudalis (nPontc), nucleus reticularis parvocellularis (nParv), and nucleus reticularis gigantocellularis (Rgc) were studied. These were classified as phasic or tonic depending on their firing pattern during the fictive jaw movement cycle. Phasic neurons located in the dorsal part of nPontc were active during the jaw opening phase, whilst those in dorsal nParv tended to fire during the closing phase. In most neurons, burst duration and firing frequency changed between the two motor patterns, but there was little change in phase of firing. Tonic units were mainly recorded in the ventral half of nPontc, and at the junction between Rgc and caudal nParv. Cortical inputs with short latency from the contralateral masticatory area were more frequent in phasic (82%) than tonic (44%) neurons, whilst inputs from the ipsilateral cortex were equal in the two subgroups (57% and 56%). Phasic neurons had significantly shorter mean contralateral than ipsilateral cortical latencies, whilst there was no difference among tonic neurons. Intra- and perioral primary afferent inputs activated both types of neurons at oligo-synaptic latencies. Our results show that subpopulations of neurons in medial reticular nuclei extending from the caudal part of the trigeminal motor nucleus to the rostral third of the hypoglossal motor nucleus are active during the fictive masticatory motor behaviour. Unlike masticatory neurons in the lateral tegmentum, the medial subpopulations are spatially organized according to discharge pattern. [source] Upper and Lower Cluster Headache: Clinical and Pathogenetic Observations in 608 PatientsHEADACHE, Issue 7 2002Carola Cademartiri MD Objective, Background, and Methods.,Ever since it was proposed by Ekbom and Kugelberg back in 1968 on the basis of the different location of head pain during attacks, the differentiation of cluster headache into an upper syndrome (US) and a lower syndrome (LS) has been regarded as a purely academic distinction. To evaluate whether this differentiation is indeed well founded and to understand its possible significance in the light of current pathogenetic knowledge, we rigorously applied Ekbom and Kugelberg's classification criteria to a sample of 608 patients with cluster headache (CH; 440 men and 168 women), including 483 with episodic CH, 69 with chronic CH, and 56 with CH periodicity undetermined. Results.,Of these patients, 278 could be classified as US sufferers and 330 as LS sufferers. Our data analysis showed statistically significant clinical differences between the two syndromes: pain location was more common in the ocular, temporal, and nuchal regions among LS sufferers; in addition, patients with LS reported not only a higher rate of autonomic symptoms, but also a higher predominance of nasal congestion, ptosis, and forehead and facial sweating among these symptoms. Conclusions.,Based on current anatomofunctional knowledge and on the most recent pathogenetic findings, we believe that changes in hypothalamic activity posteroinferiorly may lead to activation of the caudal part of the spinal trigeminal nucleus by way of the hypothalamus, midbrain, and trigeminal nerve fibers and consequently to activation of the trigeminovascular system with a different location in the two syndromes. More specifically, there seems to be a larger and more extensive involvement of the subnucleus caudalis in LS compared with US, where only its ventrocaudal portions are likely to be affected. [source] Fibre type composition of the human psoas major muscle with regard to the level of its originJOURNAL OF ANATOMY, Issue 6 2009Juraj Arbanas Abstract The aim of our study was to explore the fibre type composition of the human psoas major muscle at different levels of its origin, from the first lumbar to the fourth lumbar vertebra, and to compare the muscle fibre size and distribution of different fibre types between levels with respect to its complex postural and dynamic function. Muscle samples were collected from 15 young males (younger than 35 years). Serial transverse sections (5 ,m) of the samples were cut by cryomicrotome. Type I, IIA and IIX muscle fibres were typed using myosin heavy chain identification. The serial sections were analysed using a light microscope with a magnitude of 100×. The differences between measurements were evaluated using a repeated-measures anova and Scheffé test for post-hoc analysis. Our study showed that the human psoas major muscle was composed of type I, IIA and IIX muscle fibres. It had a predominance of type IIA muscle fibres, whereas type I muscle fibres had the largest cross-sectional area. Type IIX muscle fibres were present as a far smaller percentage and had the smallest cross-sectional area. Moreover, the fibre type composition of the psoas major muscle was different between levels of its origin starting from the first lumbar to the fourth lumbar vertebra. We conclude that the fibre type composition of the psoas major muscle indicated its dynamic and postural functions, which supports the fact that it is the main flexor of the hip joint (dynamic function) and stabilizer of the lumbar spine, sacroiliac and hip joints (postural function). The cranial part of the psoas major muscle has a primarily postural role, whereas the caudal part of the muscle has a dynamic role. [source] Recombinant human bone morphogenetic protein-7 in maxillary sinus floor elevation surgery in 3 patients compared to autogenous bone graftsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 9 2000A clinical pilot study Abstract Background/Aims: This pilot study was designed to determine the clinical bone formation ability of a human recombinant DNA bone morphogenetic protein-7, also referred to as Osteogenic Protein-1 [OP-1] combined with a collagen carrier, implanted in the maxillary sinus of 3 patients. The results were compared with a group of 3 patients treated with sinus floor elevation and autogenous bonegrafts. Methods: 6 consecutive patients, 4 female and 2 male, between 48 and 57 years of age were treated by means of sinus floor elevation for insufficient bone height in the posterior maxilla for implant surgery. 3 patients, 2 female and 1 male, were treated with OP-1 attached to a collagen device. In these patients, 4 maxillary sinus grafting procedures according to Tatum's method were carried out. 1 g of collagen carrier containing 2.5 mg rhOP-1 mixed with 3 ml of saline was placed between the bony floor and the elevated mucosal lining of the most caudal part of the maxillary sinus, in order to increase the vertical bone dimension to place dental implants of a sufficient length. The 3 other patients, also 2 female and 1 male, with a total of 5 sinus sites, were treated with sinus floor elevation and autogenous iliac crest bonegrafts. After 6 months, during dental implant preparation, bone cores were taken for histology. Thus, clinical, radiological and histological results of the 2 groups of 3 patients were compared. Results: 6 months after sinus grafting with OP-1, in 1 male, well-vascularized bonelike tissue of good quality was observed clinically. This could be confirmed by histology. In the second, female, patient no bone formation was observed at all. A cyst-like granular tissue mass, without purulent content, was removed. In the 3rd, female, patient, who received bilateral sinus grafts, some bonelike formation was seen, however it showed flexible tissue which led to the decision that at 6 months after the sinus grafting, the implant placement had to be postponed. In all 5 autogenous grafted sinuses a bone appearance similar to normal maxillary bone was observed clinically as well as histologically and dental implants could be placed six months after sinus floor elevation surgery. Conclusions: These findings indicate that the OP-1 device has the potential for initiating bone formation in the human maxillary sinus within 6 months after a sinus floor elevation operation. However, the various findings in these 3 patients indicate that the behaviour of the material is at this moment insufficiently predictable, in this indication area. Further investigation is indicated before OP-1 can be successfully used instead of the "gold standard" autogenous bone graft. [source] New method for the detection of intraperitoneal free air by sonography: Scissors maneuverJOURNAL OF CLINICAL ULTRASOUND, Issue 8 2004Okkes Ibrahim Karahan MD Abstract Purpose This study was conducted to investigate the diagnostic value of a new sonographic technique for the detection of intraabdominal free air. Methods Seventy-two patients with a suspected gastrointestinal tract perforation were included in the study and prospectively evaluated by sonography and abdominal and chest radiography for the detection of intraperitoneal free air. A new sonographic technique (the scissors maneuver) was used to detect intraperitoneal free air superficial to the liver; the maneuver consists of applying and then releasing slight pressure onto the abdominal wall with the caudal part of a parasagittaly oriented linear-array probe. The results of the imaging studies were correlated with surgical findings when possible. Results Sixteen patients had a surgically proven gastrointestinal tract perforation causing pneumoperitoneum. Sonography and radiography each showed pneumoperitoneum in 15 patients, with 1 false-negative result for each modality. The sensitivity and specificity values of sonography and radiography were identical; sensitivity was 94% and specificity was 100% for both imaging modalities. The scissors maneuver was positive in all patients with sonographically detected pneumoperitoneum. Conclusions Sonography is an effective tool in the diagnosis of pneumoperitoneum, with sensitivity and specificity equal to those of radiography. The scissors maneuver may be a useful adjunct for improving the diagnostic yield of sonography. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:381,385, 2004 [source] Influence of Serotonin on the Development and Migration of Gonadotropin-Releasing Hormone Neurones in Rat FoetusesJOURNAL OF NEUROENDOCRINOLOGY, Issue 6 2003T. Pronina Abstract This study used a pharmacological approach to evaluate the consequences of the metabolic perturbations of neurotransmitters on brain development. Pregnant rats received p-chlorophenylalanine (pCPA), an inhibitor of serotonin (5-hydroxytryptamine, 5-HT) synthesis, or saline (control) from the 11th day of gestation once or daily up to the 15th, 17th and 20th day, followed by processing of the forebrain and/or nasal cranium of foetal males and females for high-performance liquid chromatography of monoamines, radioimmunoassay of gonadotropin-releasing hormone (GnRH) and quantitative and semiquantitative immunocytochemistry for GnRH. The pCPA treatment resulted in a 50,70% depletion of 5-HT in the nasal crania and forebrains at any studied age. Radioimmunoassay showed no change in GnRH content in 5-HT deficient foetuses at E16 compared to controls, being higher in both cases in the rostral forebrain than in the hypothalamus. In controls at E21, the GnRH content in the hypothalamus exceeded that in the rostral forebrain, whereas in the 5-HT deficient group the opposite was found. These data suggest that 5-HT provided a stimulating effect on GnRH neurone migration, and this was confirmed by quantification of GnRH-immunoreactive neurones in the forebrain along the trajectory of their migration. At E18 and E21, the fractions of GnRH neurones in the rostral part of the trajectory in pCPA-treated foetuses were greater than those in control foetuses but the opposite was true for the caudal part of the trajectory. Moreover, 5-HT appeared to control the proliferation of the precursor cells of GnRH neurones and their differentiation, as derived from the observations of the increased number of GnRH neurones in the forebrain of foetuses of both sexes, as well as the region-specific decreased neuronal size and content of GnRH in 5-HT-deficient females. Thus, 5-HT appears to contribute to the regulation of the origin, differentiation and migration of GnRH neurones. [source] Gender-related changes in the avian vasotocin system during ontogenyMICROSCOPY RESEARCH AND TECHNIQUE, Issue 1 2001Aleksandr Jurkevich Abstract The arginine vasotocin (AVT) system of the avian brain includes a sexually dimorphic part that extends from the caudal part of preoptic region through the medial part of the bed nucleus of stria terminalis (BSTm) to the lateral septum. It is composed of the parvocellular neurons located in the BSTm and the dense innervation of the medial preoptic region and lateral septum. In this part of the brain, AVT expression is stronger in males than in females in a few bird species investigated to date. This review focuses on the ontogeny of sexual differences in the vasotocinergic system of two gallinaceous species, domestic chicken and Japanese quail, and on the role of gonadal hormones in organizing during development and maintaining in adulthood these differences. Parvocellular AVT neurons become discernible in the BSTm of males and females during the second half of embryonic development. These cells undergo a profound and irreversible sexual differentiation during ontogenetic development. Recent findings demonstrate a dual role of estrogens in the organization and activation of sex differences in the AVT system. During the embryonic period of ontogeny, estrogens differentiate the AVT system in a sexually dimorphic manner in parallel with the differentiation of sexual behavior, while in adulthood estrogens, locally produced from testosterone in the male brain, activate AVT synthesis in the BSTm. The sexually dimorphic part of the AVT system is sensitive to a number of abiotic factors such as light, temperature, and water availability. It is suggested that sex dimorphic vasotocinergic systems could be implicated in processes of social recognition in various behavioral contexts. Microsc. Res. Tech. 55:27,36, 2001. © 2001 Wiley-Liss, Inc. [source] Brain dopaminergic modulation associated with executive function in Parkinson's disease,MOVEMENT DISORDERS, Issue 13 2009Karim Farid MD Abstract The progressive development of deficits in executive functions, including action planning, is a well-known complication of Parkinson's disease. A dysfunction of the prefrontal lobe, which is known to be involved in the control of inhibitory processes, could explain the difficulties in initiating behavior or inhibiting ongoing actions in patients with PD. The strong dopaminergic innervation of the prefrontal cortex raises questions about the putative effects of dopa therapy on this cognitive impairment. In the present study, we used fMRI to examine the functional influence of dopa therapy on neural activity during a go/no-go task in nine patients with and without levodopa treatment and in matched controls. Whereas the patient and control subjects exhibited the same performance during the go/no-go task, different patterns of brain activation were observed depending on the dopaminergic status. The drug-off state was characterized by more widely distributed brain activity, mainly in the bilateral caudate. Levodopa did not fully restore normal brain activation and induced changes in the pattern of cingulate cortex activity, which was more pronounced in the rostral part in the drug-off state and in the caudal part after levodopa intake. These results support the idea of a critical role for dopamine in the control of executive functions in patients with PD. © 2009 Movement Disorder Society [source] Jaw Mechanics in Basal Ceratopsia (Ornithischia, Dinosauria)THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 9 2009Kyo Tanoue Abstract Ceratopsian dinosaurs were a dominant group of herbivores in Cretaceous terrestrial ecosystems. We hypothesize that an understanding of the feeding system will provide important insight into the evolutionary success of these animals. The mandibular mechanics of eight genera of basal ceratopsians was examined to understand the variability in shape of the jaws and the early evolution of the masticatory system in Ceratopsia. Data were collected on lever arms, cranial angles and tooth row lengths. The results indicate that psittacosaurids had higher leverage at the beak and in the rostral part of the tooth row than basal neoceratopsians, but lower leverage in the caudal part of the tooth row. Although the vertebrate mandible is generally considered as a third-class lever, that of basal neoceratopsians acted as a second-class lever at the caudal part of the tooth row, as is also true in ceratopsids. When total input force from the mandibular adductor muscles on both sides of the skull is considered, the largest bite force in basal ceratopsian tooth rows was exerted in the caudal part of the tooth row at the caudal extremity of the zone with near-maximum input force. Medially positioned teeth generate higher leverage than laterally positioned teeth. The largest bite force in all basal ceratopsians is smaller than the maximum input force, a limit imposed by the morphology of the basal ceratopsian masticatory system. In ceratopsids, caudal extension of the tooth row resulted in a much larger bite force, even exceeding the maximum input force. Anat Rec, 292:1352,1369, 2009. © 2009 Wiley-Liss, Inc. [source] Development of the Mesonephros in Camel (Camelus dromedarius)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2007K. H. Aly Summary The study of the development of the mesonephros in the camel (Camelus dromedarius) was carried out on 16 embryos ranging from 0.9 to 8.6 cm crown vertebral rump length (CVRL). At 0.9 cm CVRL, the mesonephros is represented by a narrow strip along the roof of the thoracolumbar part of the vertebral column. At 1.4 cm CVRL, some of the mesonephric tubules are canalized but others are still solid. The mesonephric corpuscles are well developed at 1.9 cm CVRL and occupy almost the entire abdominal cavity in between the liver and the gut. Histologically, the glomeruli occupy the ventromedial aspect of the mesonephros while the mesonephric tubules become numerous, larger and more coiled. At 3 cm CVRL, the metanephros is invaginated in the caudal pole of the mesonephros, and the mesonephric tubules in some areas are differentiated into secretory and collecting tubules. At 3.5 cm CVRL the mesonephros is related dorsally to the postcardinal vein and ventrally to the subcardinal vein. At 4.7 cm CVRL continuous regression of the mesonephros from cranialwards to caudalwards is observed. At 5.3,5.5 cm CVRL, the cranial part of the mesonephros is divided into medial and lateral regions, and later the medial region completely disappears and is replaced by the primordium of the adrenal gland. At 8.6 cm CVRL, the caudal part of the mesonephros completely disappears. [source] Thalamic label patterns suggest primary and ventral auditory fields are distinct core regionsTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 10 2010Douglas A. Storace Abstract A hierarchical scheme proposed by Kaas and colleagues suggests that primate auditory cortex can be divided into core and belt regions based on anatomic connections with thalamus and distinctions among response properties. According to their model, core auditory cortex receives predominantly unimodal sensory input from the ventral nucleus of the medial geniculate body (MGBv); whereas belt cortex receives predominantly cross-modal sensory input from nuclei outside the MGBv. We previously characterized distinct response properties in rat primary (A1) versus ventral auditory field (VAF) cortex; however, it has been unclear whether VAF should be categorized as a core or belt auditory cortex. The current study employed high-resolution functional imaging to map intrinsic metabolic responses to tones and to guide retrograde tracer injections into A1 and VAF. The size and density of retrogradely labeled somas in the medial geniculate body (MGB) were examined as a function of their position along the caudal-to-rostral axis, subdivision of origin, and cortical projection target. A1 and VAF projecting neurons were found in the same subdivisions of the MGB but in rostral and caudal parts, respectively. Less than 3% of the cells projected to both regions. VAF projecting neurons were smaller than A1 projecting neurons located in dorsal (MGBd) and suprageniculate (SG) nuclei. Thus, soma size varied with both caudal-rostral position and cortical target. Finally, the majority (>70%) of A1 and VAF projecting neurons were located in MGBv. These MGB connection profiles suggest that rat auditory cortex, like primate auditory cortex, is made up of multiple distinct core regions. J. Comp. Neurol. 518:1630,1646, 2010. © 2010 Wiley-Liss, Inc. [source] | |||||||||||||