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1.
R. Necker A. Janßen T. Beissenhirtz 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2000,186(4):409-412
In birds there are anatomical specializations in the lumbosacral vertebrae and spinal cord. These include segmentally organized
bony canals which are related to accessory lobes of the spinal cord. Both structures are connected by cerebrospinal fluid.
To test whether these specializations function as a sense organ of equilibrium the effect of opening the fluid space was studied
in pigeons. Locomotory behaviors on the ground (landing on a perch, keeping balance on a rotating perch, walking) but not
flight were significantly impaired after lesion. These results support the assumption that the lumbosacral specializations
are involved in the control of locomotion on the ground.
Accepted: 12 March 2000 相似文献
2.
The prominent accessory lobes of Lachi in birds are considered to be marginal nuclei; similar nuclei have been implicated in mechanoreceptive functions in snakes and lampreys. Reptile studies emphasized the involvement of the denticulate ligament with this mechanoreceptive function. This investigation examines the fine structure of the accessory lobes of Lachi in pigeons and their interaction with ligaments for features which might support such a mechanoreceptive function. In the lumbosacral area of the spinal cord, the lateral longitudinal ligaments and the ventral longitudinal ligament are hypertrophied. The ventral transverse ligaments are present only within the lumbosacral segments of the spinal cord and they interconnect with the lateral and ventral longitudinal ligaments. The lateral longitudinal ligament makes intimate contact with the spinal cord, and many glial processes from the spinal cord mingle with and are firmly attached to collagenous fibers of the ligament. The lobes lie dorsal to the lateral longitudinal ligament in the exact area where it interconnects with the transverse ligament. The lobe's multipolar neurons have a number of synaptic contacts but no unusual specializations were noted. Most of each lobe is composed of interdigitating saccular structures filled to varying degrees with flocculent material. The sacs are extensions of the cytoplasm of neuroglial cells, which also give rise to membranes surrounding neuronal processes and the sacs themselves. A possible functional relationship of the lobes and the ligaments of the lumbosacral spinal segments within the vertebral column is described. 相似文献
3.
Yuki Suzuki Naoki Kitamura Yuko Yamanaka Izumi Shibuya 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2014,200(8):739-748
Birds have ten pairs of protrusions, “accessory lobes”, on the lateral sides of the lumbosacral spinal cord. It has been proposed that accessory lobes act as a sensory organ of equilibrium and neurons in accessory lobes transmit sensory information to the motor center. We have reported that cells in chick accessory lobes express functional voltage-gated Na+ and K+ channels and generate action potentials. In this study, we examined properties of voltage-gated Ca2+ channels (VGCCs). The amplitude of voltage-gated Ca2+ channel currents carried by Ca2+ and Ba2+ increased gradually during 10 min rather than showing the usual run-down. The current–voltage relationship of Ba2+ currents was consistent with that of the high-voltage-activated Ca2+ channel. The proportion of Ba2+ currents inhibited by ω-conotoxin GVIA was larger than 80 %, indicating that the major subtype is N type. Amplitudes of tail currents of Ca2+ currents evoked by repetitive pulses at 50 Hz are stable for 1 s. If the major subtype of VGCCs at synaptic terminals is also N type, this property may contribute to the establishment of stable synaptic connections between accessory lobe neurons, which are reported to fire at frequencies higher than 15 Hz, and postsynaptic neurons in the spinal cord. 相似文献
4.
Iu S Sverdlov T Iu Ruchinskaia 《Biulleten' eksperimental'no? biologii i meditsiny》1984,97(1):103-104
A method for in-vivo long-lasting perfusion of the central canal of the cat lumbosacral spinal cord with artificial cerebrospinal fluid is described. The method provides for a stable continuous flow of perfusion fluid for many hours. The perfusion adjustment does not entail any injuries to the inferior lumbar and sacral segments of the spinal cord or their roots. 相似文献
5.
6.
P D'Ascanio N Corvaja I Grofova 《Bollettino della Società italiana di biologia sperimentale》1979,55(19):1966-1969
The origin of the vestibulospinal projection in the toad has been investigated by using the method of the retrograde axonal transport of HRP injected at various levels of the spinal cord. The vestibulospinal projection, in this species, was found to be somatotopically organized, since neurons projecting to the cervical segments of the spinal cord were located within the rostromedial part of the ventral vestibular nucleus and those neurons projecting to the lumbosacral segments of the spinal cord were located within the caudolateral part of that nucleus. This pattern of organization of the vestibulospinal projection in amphibia is similar to that described in mammals and birds. 相似文献
7.
The effects of the pathogenic influence of botulin toxin on different types of spinal motor neurons]
The motor neuron cells of the lumbosacral region were investigated in the spinal cord of cat with the local botulin paralysis. Development of this paralysis was followed by reduction of the membrane potential, of the amplitude of antidromic AP, mono- and polysynaptic EPSP, a fall of the input resistance and by an increase in the level of the critical depolarization of the somatic membrane of the phasic motor neurons of the damaged segments in the spinal cord. Excitation of the tonic motor neurons was not greatly altered in the dynamics of local botulism. 相似文献
8.
《Electronic Notes in Theoretical Computer Science》1996,100(1):68-73
Slow negative (N) and slow positive (P) waves are frequently produced in the posterior epidural space at the lumbosacral enlargement by epidural stimulation of the rostral part of human spinal cord. The production of these slow potentials are thought to be responsible for analgesia at the stimulated segment as well as below that level. In order to define the spinal tract which mediates these slow potentials, we stimulated directly or from the epidural space the dorsal, dorsolateral, lateral and ventral columns at the cervical or thoracic level, and epidurally recorded spinal cord potentials (des.SCPs) at the lumbosacral enlargement in 7 patients who underwent spine or spinal cord surgery. The des.SCPs recorded in the lumbosacral enlargement consisted of polyphasic spike potentials followed by slow N and P waves. At a near threshold level of stimulus intensity the slow N and P potentials were consistently elicited only by stimulation of the dorsal column. The slow waves were also produced by intense stimulation of other tracts, but remained significantly (P < 0.05−P <0.01) smaller than those evoked by dorsal column stimulation when compared at the same stimulus intensity. Moreover, the slow P wave could not be elicited even by intense stimulation (10 times the threshold strength for the initial spike potentials) of the ventral column. Thus, the results suggest that the slow N and P waves are mostly mediated by the antidromic impulses descending through the dorsal column. 相似文献
9.
Giuliano F Bernabé J McKenna K Longueville F Rampin O 《American journal of physiology. Regulatory, integrative and comparative physiology》2001,280(6):R1870-R1877
The spinal cord contains the neural network that controls penile erection. This network is activated by information from peripheral and supraspinal origin. We tested the hypothesis that oxytocin (OT), released at the lumbosacral spinal cord level by descending projections from the paraventricular nucleus, regulated penile erection. In anesthetized male rats, blood pressure and intracavernous pressure (ICP) were monitored. Intrathecal (it) injection of cumulative doses of OT and the selective OT agonist [Thr(4),Gly(7)]OT at the lumbosacral level elicited ICP rises whose number, amplitude, and area were dose dependent. Thirty nanograms of OT and one-hundred nanograms of the agonist displayed the greatest proerectile effects. Single injections of OT also elicited ICP rises. Preliminary injection of a specific OT-receptor antagonist, hexamethonium, or bilateral pelvic nerve section impaired the effects of OT injected it. NaCl and vasopressin injected it at the lumbosacral level and OT injected it at the thoracolumbar level or intravenously had no effect on ICP. The results demonstrate that OT, acting at the lumbosacral spinal cord, elicits ICP rises in anesthetized rats. They suggest that OT, released on physiological activation of the PVN in a sexually relevant context, is a potent activator of spinal proerectile neurons. 相似文献
10.
Background
Exogenous NGF or saline was delivered to the detrusor smooth muscle of female rats for a two-week period using osmotic mini-pumps. We then determined: (1) bladder function using conscious cystometry; (2) organization of micturition reflexes using Fos protein expression in lumbosacral (L5-S1) spinal cord neurons; (3) calcitonin gene-related peptide (CGRP)-immunoreactivity (IR) in lumbosacral spinal cord segments. 相似文献11.
Curtailed (Tc), a dominant mutation on mouse chromosome 17, causes a tailless phenotype and occasional hindlimb paralysis in heterozygotes. Histologically, Tc/+ embryos show a variety of abnormalities including budding and ventral duplication of the developing spinal cord, duplication and intermittent absence of the notochord, and partial or complete absence of bony vertebrae, all posterior to midliver level. When Tc is heterozygous with t-haplotypes that contain the "tail interaction factor," tct, the phenotype is more severe, and a dorsal blood blister exists in the lumbosacral area. Our microscopic observations reveal that Tc/tw5 mice have a lumbosacral spina bifida with meningomyelocele. This results from the absence of bony vertebrae, extensive thinning of the dermis dorsally, and the rupturing of the previously closed neural tube, probably by increased cerebrospinal fluid (CSF) pressure on the necrotic, attenuated roof plate. Thinning of the roof plate, which facilitates the rupturing of the spinal cord, is not observed in Tc/+, which suggests that this phenomenon is associated with the interaction of Tc with the t-allele. Later in the development of Tc/tw5 embryos, adjacent blood vessels are ruptured, resulting in hemorrhage into the CSF space to give the external appearance of a blood blister. Tc/+ mice also show an absence of bony vertebrae dorsally in the lumbosacral region, but they lack the dorsal blood blister, and the dermal layer overlying the bony defect retains its normal thickness; these observations describe a spina bifida occulta. 相似文献
12.
Vizzard MA 《American journal of physiology. Regulatory, integrative and comparative physiology》2000,279(1):R295-R305
These studies examined Fos protein expression in spinal cord neurons synaptically activated by stimulation of bladder afferent pathways after spinal cord injury (SCI). In urethan-anesthetized Wistar rats after SCI for 6 wk, intravesical saline distension significantly (P = 0.005) increased the number of Fos-immunoreactive (IR) cells in the rostrolumbar (L1, 38 cells/section; L2, 29 cells/section) and caudal lumbosacral (L6, 140 cells/section; S1, 110 cells/section) spinal cord compared with control animals, but Fos expression in the L5 segment was not altered. The distribution of Fos-IR cells was also altered in the lumbosacral spinal cord. Significantly greater numbers of Fos-IR cells were distributed in the dorsal commissure and medial and lateral dorsal horn after intravesical distension in SCI animals. Large percentages of parasympathetic (75%) and sympathetic (85%) preganglionic neurons also expressed Fos-IR after intravesical distension in SCI animals. These results demonstrate that bladder distension produces increased numbers and an altered distribution pattern of Fos-IR cells after SCI. This pattern resembles that after noxious irritation of the bladder in control animals. Pretreatment with capsaicin significantly reduced the number of Fos-IR cells induced by bladder distension after SCI. These data suggest that SCI can reveal an altered Fos expression pattern in response to a nonnoxious bladder stimulus that is partially mediated by capsaicin-sensitive bladder afferents. 相似文献
13.
神经移植的新途径--移植的中枢神经元从蛛网膜下腔迁入脊髓和大脑皮层 总被引:1,自引:0,他引:1
我们在神经移植的天空过程中观察到被移植的中枢神经元能从蛛网膜下腔迁入脊髓的大脑皮层。这一新观察为脊髓和脑浅层大范围神经元缺损时的无损伤神经元引入和大范围去神经区域的神经再支配提供了一种颇具吸引力的河能性。实验动物选用Wistar和S.D.大鼠,将含有胚胎中枢单胺或精氨酸血管加压素(AVP)能神经元的细胞悬浮液或组织块移植到被横断的脊髓或未被脊髓和脑的蛛网膜下腔内。动物分别在移植的同时切断脊髓;在移 相似文献
14.
The frequent use of the adult rat sciatic nerve as a model to study the neuronal responses to injury, nerve regeneration and in transplantation studies, requires a detailed knowledge of the projection pattern of motor neurons into this nerve. Thus, as a first goal we determined this topographical projection of motor neurons and labelled small contingents by applying the fluorescent dye DiI in localised incisions made in the dorsal, rostral, ventral or caudal quadrants of the nerve. As a second goal we analysed with immunohistochemical methods the response of microglial cells within the topographical area corresponding to the incision and within areas outside this location. Uptake of the dye occurred only within the area confined to the incision, thus allowing the identification of the corresponding motor neuron perikarya within the ventral horn, eight to ten days later. In serial transverse sections of the lumbosacral spinal cord the number of labelled cells, their position within the ventral horn, and their longitudinal extent have been determined. The data suggest that the gross projection of the lumbosacral motor neuron column at the mid-thigh level of the sciatic nerve is topographic. In accordance, microglial cells showed fast activation within the injured topographic area, and a less pronounced and delayed response within the non-injured areas of the ventral horn. The graded response of microglial cells suggests that these cells possess a potential of local activation by sensing whether neurons are axotomised or just irritated by axotomy of their neighbours. The topographic organisation proves to be useful in studies on local injuries to the sciatic nerve and when analysing retrograde responses within the lumbosacral spinal cord. 相似文献
15.
E D Pollack 《The American journal of anatomy》1976,147(2):183-192
The extent of mitotic activity in the proliferative ventricular zone of the developing frog (Rana pipiens) spinal cord is a function of both the longitudinal cord level and the developmental stage. Counts of mitotic cells in the ventricular zone demonstrated higher levels of proliferation in the dorsal than ventral halves of the spinal cord with decreasing total proliferative activity from the early to late larval (tadpole) stages. Mitoses were virtually absent from the ventricular zone by the conclusion of metamorphosis. Changes in mitotic counts at different levels of the spinal cord can be correlated with the presence or absence of the brachial or lumbosacral pairs of lateral motor columns. A parallel also exists between the caudo-cephalic direction of motor column development and a similar progression of mitotic activity in the ventricular zone, a portion of which gives rise to the spinal motor neurons. It is suggested that proliferation in the ventricular zone during the larval frog stages contributes to the presumptive motor neuron population and migrates into the lateral motor columns during their later maturation. 相似文献
16.
T. K. Kipriyan 《Neurophysiology》1974,6(3):203-207
The effect of the corticosteroid hormone hydrocortisone on electrical activity in the lumbosacral portion of the spinal cord was studied in acute experiments on cats anesthetized with urethane and chloralose and immobilized with succinylcholine. The amplitude of mono- and polysynaptic discharges arising in the ventral roots in response to stimulation of various afferents of the animal's hind limb was increased by a statistically significant degree after intravenous injection of the hormone. The potentiating action of the hormone was strongest and most stable with respect to early and late postsynaptic potentials of the spinal cord. The dorsal cord potentials were not significantly changed by hydrocortisone. Spontaneous unit activity in the intermediate nucleus of the spinal cord rose sharply after administration of hydrocortisone. Before the action of the hormone the mean frequency of spontaneous discharges of 46 neurons was 7.91/sec, rising to 20/sec after the injection. The number of neurons with a high spontaneous firing rate also was increased. Prolonged extracellular recording of the spontaneous activity of the same neuron before and after administration of hydrocortisone also revealed a marked increase in the frequency of its discharges. The results are evidence of the activating effect of hydrocortisone on spinal interneuronal activity. 相似文献
17.
Jessica R. Benson Jiameng Xu Derek M. Moynes Tamia K. Lapointe Christophe Altier Stephen J. Vanner Alan E. Lomax 《Cell and tissue research》2014,356(2):309-317
Sensitization of dorsal root ganglia (DRG) neurons is an important mechanism underlying the expression of chronic abdominal pain caused by intestinal inflammation. Most studies have focused on changes in the peripheral terminals of DRG neurons in the inflamed intestine but recent evidence suggests that the sprouting of central nerve terminals in the dorsal horn is also important. Therefore, we examine the time course and reversibility of changes in the distribution of immunoreactivity for substance P (SP), a marker of the central terminals of DRG neurons, in the spinal cord during and following dextran sulphate sodium (DSS)-induced colitis in mice. Acute and chronic treatment with DSS significantly increased SP immunoreactivity in thoracic and lumbosacral spinal cord segments. This increase developed over several weeks and was evident in both the superficial laminae of the dorsal horn and in lamina X. These increases persisted for 5 weeks following cessation of both the acute and chronic models. The increase in SP immunoreactivity was not observed in segments of the cervical spinal cord, which were not innervated by the axons of colonic afferent neurons. DRG neurons dissociated following acute DSS-colitis exhibited increased neurite sprouting compared with neurons dissociated from control mice. These data suggest significant colitis-induced enhancements in neuropeptide expression in DRG neuron central terminals. Such neurotransmitter plasticity persists beyond the period of active inflammation and might contribute to a sustained increase in nociceptive signaling following the resolution of inflammation. 相似文献
18.
Spinocerebellar neurons have been found in previous studies in lamina IX of the lumbosacral spinal cord. This lamina has been characterized as being composed of motor cell groups and the spinocerebellar neurons in the lamina have been found to have certain morphological similarities with the motoneurons. Retrograde double labeling technique, utilizing fluorescent dyes, was used for studying the relations between the spinocerebellar neurons and the motoneurons in lamina IX of the lumbosacral spinal cord in four adult cats. In three of them, Rhodamine labeled latex microspheres were injected bilaterally into the cerebellum and Fast Blue (FB) was injected into hindlimb nerves. In the fourth case, FB was injected into the cerebellum, while the peripheral nerves were injected with propidium iodide. Some overlap was found between labeled spinocerebellar neurons and motoneurons in certain parts of lamina IX, especially in the ventrolateral nucleus in the caudal part of L5 and rostral L6, in the dorsolateral nucleus from the caudal part of L5 to L6 and in the ventromedial nucleus at the S2 level. No double labeled neurons were found, however, in any of these or in other examined areas. This strongly indicates that spinocerebellar neurons in lamina IX are a separate population, different from motoneurons. 相似文献
19.
Histochemical characterization of NADPH diaphorase positive neuronal pools in the rabbit lumbosacral segments was performed during and after transient spinal cord ischemia. Strongly enhanced staining of NADPH diaphorase positive structures appeared in the superficial dorsal horn, the pericentral region and in the neurons of the sacral parasympathetic nucleus at the end of 40 min of abdominal aorta ligation or after 1 day reperfusion. Four days after ischemia, NADPH-d positive neurons and vessels were detected in the central gray matter despite well developed necrosis in this location. Regional nitric oxide synthesis and its vasodilatatory effect during the period of aortic occlusion may account for the observed selective resistance of these spinal cord neurons to transient ischemia. 相似文献
20.
Recently, we found that gentle mechanical skin stimulation inhibits the micturition reflex in anesthetized rats. However, the central mechanisms underlying this inhibition have not been determined. This study aimed to clarify the central neural mechanisms underlying this inhibitory effect. In urethane-anesthetized rats, cutaneous stimuli were applied for 1 min to the skin of the perineum using an elastic polymer roller with a smooth, soft surface. Inhibition of rhythmic micturition contractions by perineal stimulation was abolished by naloxone, an antagonist of opioidergic receptors, administered into the intrathecal space of the lumbosacral spinal cord at doses of 2–20 μg but was not affected by the same doses of naloxone administered into the subarachnoid space of the cisterna magna. Next, we examined whether perineal rolling stimulation inhibited the descending and ascending limbs of the micturition reflex. Perineal rolling stimulation inhibited bladder contractions induced by electrical stimulation of the pontine micturition center (PMC) or the descending tract of the micturition reflex pathway. It also inhibited the bladder distension-induced increase in the blood flow of the dorsal cord at L5–S1, reflecting the neural activity of this area, as well as pelvic afferent-evoked field potentials in the dorsal commissure at the lumbosacral level; these areas contain long ascending neurons to the PMC. Neuronal activities in this center were also inhibited by the rolling stimulation. These results suggest that the perineal rolling stimulation activates the spinal opioidergic system and inhibits both ascending and descending transmissions of the micturition reflex pathway in the spinal cord. These inhibitions would lead to the shutting down of positive feedback between the bladder and the PMC, resulting in inhibition of the micturition reflex. Based on the central neural mechanisms we show here, gentle perineal stimulation may be applicable to several different types of overactive bladder. 相似文献