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Spinal Segments (spinal + segment)
Selected AbstractsRole of the Neurokinin-1 Receptors in Ejaculation in Anesthetized RatsTHE JOURNAL OF SEXUAL MEDICINE, Issue 1 2009Pierre Clement PhD ABSTRACT Introduction., Several lines of evidence indicate a role for substance P in the control of ejaculation, although its mode of action needs to be clarified. Aim., The effects and sites of action of a selective antagonist for the substance P-preferred receptor (neurokinin-1 receptor subtype; NK1) were investigated in a pharmacological model of ejaculation. Methods., Ejaculation was induced in anesthetized rats by intracerebroventricular (icv) delivery of the dopamine D3 receptor preferring agonist 7-hydroxy-2-(di-N-propylamino)tetralin (7-OH-DPAT). The effects of the selective NK1 antagonist RP67580 on 7-OH-DPAT-induced ejaculation were measured following intraperitoneal (ip), icv, or intrathecal (it) (third lumbar spinal segment; L3) administration. Main Outcome Measures., Intraseminal vesicle pressure (SVP) and electromyogram of the bulbospongiosus muscle (BS) were recorded as physiological markers of emission and expulsion phases of ejaculation, respectively. Results., Upon ip, icv, or it administration, RP67580 significantly reduced the occurrence of ejaculation elicited by 7-OH-DPAT. A mild decrease in the occurrence of SVP and BS responses was observed in rats treated ip with RP67580, whereas only SVP responses were moderately affected following icv or it administration. Conclusion., These results show the multilevel regulation of 7-OH-DPAT-induced ejaculation by NK1 receptors. Clement P, Peeters M, Bernabe J, Laurin M, Alexandre L, and Giuliano F. Role of the neurokinin-1 receptors in ejaculation in anesthetized rats. J Sex Med 2009;6:126,134. [source] Pre-/post-otic rhombomeric interactions control the emergence of a fetal-like respiratory rhythm in the mouse embryoDEVELOPMENTAL NEUROBIOLOGY, Issue 12 2006C. Borday Abstract How regional patterning of the neural tube in vertebrate embryos may influence the emergence and the function of neural networks remains elusive. We have begun to address this issue in the embryonic mouse hindbrain by studying rhythmogenic properties of different neural tube segments. We have isolated pre- and post-otic hindbrain segments and spinal segments of the mouse neural tube, when they form at embryonic day (E) 9, and grafted them into the same positions in stage-matched chick hosts. Three days after grafting, in vitro recordings of the activity in the cranial nerves exiting the grafts indicate that a high frequency (HF) rhythm (order: 10 bursts/min) is generated in post-otic segments while more anterior pre-otic and more posterior spinal territories generate a low frequency (LF) rhythm (order: 1 burst/min). Comparison with homo-specific grafting of corresponding chick segments points to conservation in mouse and chick of the link between the patterning of activities and the axial origin of the hindbrain segment. This HF rhythm is reminiscent of the respiratory rhythm known to appear at E15 in mice. We also report on pre-/post-otic interactions. The pre-otic rhombomere 5 prevents the emergence of the HF rhythm at E12. Although the nature of the interaction with r5 remains obscure, we propose that ontogeny of fetal-like respiratory circuits relies on: (i) a selective developmental program enforcing HF rhythm generation, already set at E9 in post-otic segments, and (ii) trans-segmental interactions with pre-otic territories that may control the time when this rhythm appears. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006 [source] The patterns of spontaneous Ca2+ signals generated by ventral spinal neurons in vitro show time-dependent refinementEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2009Sara Sibilla Abstract Embryonic spinal neurons maintained in organotypic slice culture are known to mimic certain maturation-dependent signalling changes. With such a model we investigated, in embryonic mouse spinal segments, the age-dependent spatio-temporal control of intracellular Ca2+ signalling generated by neuronal populations in ventral circuits and its relation with electrical activity. We used Ca2+ imaging to monitor areas located within the ventral spinal horn at 1 and 2 weeks of in vitro growth. Primitive patterns of spontaneous neuronal Ca2+ transients (detected at 1 week) were typically synchronous. Remarkably, such transients originated from widespread propagating waves that became organized into large-scale rhythmic bursts. These activities were associated with the generation of synaptically mediated inward currents under whole-cell patch-clamp. Such patterns disappeared during longer culture of spinal segments: at 2 weeks in culture, only a subset of ventral neurons displayed spontaneous, asynchronous and repetitive Ca2+ oscillations dissociated from background synaptic activity. We observed that the emergence of oscillations was a restricted phenomenon arising together with the transformation of ventral network electrophysiological bursting into asynchronous synaptic discharges. This change was accompanied by the appearance of discrete calbindin immunoreactivity against an unchanged background of calretinin-positive cells. It is attractive to assume that periodic oscillations of Ca2+ confer a summative ability to these cells to shape the plasticity of local circuits through different changes (phasic or tonic) in intracellular Ca2+. [source] Spread of ropivacaine by a weight-based formula in a pediatric caudal block: a fluoroscopic examinationACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2010B.-N. KOO Background: Caudal block is the most common regional technique to provide post-operative analgesia in pediatric infra-umbilical surgery. This study was designed to define how many spinal segments would be covered by the weight-based dosage of caudally administered 0.2% ropivacaine in children using the fluoroscopic method. Methods: After an approval from the institutional human research review board, in 83 ASA I boys undergoing day-case urological surgery, the distribution of ropivacaine mixed with a radioactive dye in relation to the volume injected caudally was studied. Three groups were studied: for perineal surgery 0.5 ml/kg (group C0.5), for inguinal hernia repair 1 ml/kg (group C1.0), and for orchiopexy 1.25 ml/kg (group C1.25). The dose of 0.2% ropivacaine containing radiopaque dye at a ratio of 1 : 4 was injected at a rate of 1 ml 3 s,1. Fluoroscopic examination was performed immediately to define the level of the drug spread within the extradural space. Results: The highest spinal levels [median with ranges] of spread were L2 [L4-T12] in group C0.5, T12 [L1-T8] in group C1.0, and T10 [L2-T7] in group C1.25. Analysis by age distribution (infants: <12 months; toddlers: 12,36 months; and children: >36 months) revealed a larger spread in younger patients. Conclusions: Based on the fluoroscopic findings, the weight-based doses for caudally administered 0.2% bupivacaine suggested by Armitage are also useful for ropivacaine to block the spinal level required for the different types of surgeries studied. [source] Motor block in regional anaesthesiaANAESTHESIA, Issue 12 2001apparatus A device based on a load cell was constructed to measure the strength of foot dorsiflexion and plantarflexion. Performance of the device was evaluated for both movements. The influence of foot position within the device, its use over a 30-min period at 30-s intervals and the effect of the removal and reapplication of the device on measured force of dorsiflexion and plantarflexion was studied in six volunteers. Both dorsiflexion and plantarflexion are suitable movements on which to base a device to quantify the density of motor block during the onset and offset of neuraxial block. Dorsiflexion has a number of advantages: muscle strength is independent of knee position, and therefore a below-knee device can be constructed; strength of dorsiflexion is less affected by the foot position; we found the device easier to apply using dorsiflexion as the heel tended to self-locate; innervation of the muscles responsible for dorsiflexion involves fewer spinal segments. [source] The Morphology of the Cervico-thoracic Sympathetic System in Donkeys (Equus asinus L.)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2009O. Ozgel Summary Five adult donkeys of both sexes, used in applied anatomy classes, and perfused with formalin for teaching purposes, constituted the study material. Ganglion cervicale caudale of the examined materials has observed to exhibit individually variable situation as to extend on the left side of the median line, at the alignment of the first and second intercostal spaces and on the right side between the level of the first and third costa. The ganglion extended more caudally on the right side of median line. The lateral surface of the ganglion was determined to be covered with the m. scalenus medius. On the both sides of the median plane, the ganglion cervicale caudale was seen to be situated on the lateral surface of the m. longus colli. On the left side, the ganglion overlapped the oesophagus in two cadavers and on the right side it was situated within a groove between the m. longus colli and trachea in three cadavers. The rami communicantes received by the ganglion cervicale caudale originated from the eighth cervical and first thoracic spinal segments. The ganglion cervicale caudale was formed by the coalescence of the last cervical and first three thoracic sympathetic ganglia. The ganglion cervicale caudale gave off branches that formed the rami communicantes, plexus cardiacus, n. vertebralis and ansa subclavia. One branch extended from the ganglion to the plexus brachialis. in one specimen, two sympathetic,parasympathetic communicating branches were observed to extend from the ansa subclavia and near by the origin of the truncus sympathicus to the n. vagus. In one of the donkeys examined, a branch originating from the ganglion cervicale caudale on the left side of the median plane was determined to end on the ligamentum arteriosum. A microscopic ganglion structure suggesting the existence of the ganglion cervicale medium was determined in a donkey. [source] | |||||||||||||