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1.
N. I. Nezlina 《Neurophysiology》1973,5(3):217-222
The possibility and degree of recovery of motor and sensory functions in cats were studied after one-stage or two-stage bilateral division of the posterior columns and spinocervical tracts at the cervical level. Blocking the afferent inflow along these systems led to severe and prolonged disturbances of sensation and motor activity and was accompanied by a sharp decrease in nociceptive sensation. Weak (6–8 V) electrical stimulation of the skin of the limbs, which evoked a primary response of maximal amplitude in intact waking animals, evoked no electrical response in the somatosensory cortex of the chordotomized animals. However, on increasing the intensity of stimulation by 2, 3, or more times, low-amplitude negative waves with a spike latency of about 15 msec, together with slow late waves, were recorded in foci of maximal activity of the cortex. Recovery of motor activity and, to some extent, of proprioception was observed 2–4 months after injury; responses to tactile stimulation were not restored. In the course of compensatory reconstruction evoked activity in the somatosensory cortex did not recover. It is concluded that the recovery of motor activity in cats after injury to the afferent systems of the spinal cord can take place despite a considerable defect of somatic sensation.Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 5, No. 3, pp. 281–288, May–June, 1973. 相似文献
2.
Kalina Vaptzarova Jacques Hanoune 《Biochimica et Biophysica Acta (BBA)/General Subjects》1976,444(3):712-718
The effect of high level section of the spinal cord upon the hepatic cyclic AMP system was investigated in the rat. We report that transection of the spinal cord dramatically decreases the basal level of cyclic AMP from 0.88 nmol/g liver to 0.36 nmol/g at 1 h and to 0.20 nmol/g at 4 h. This was not due to increased activity of cyclic AMP phosphodiesterase or to decreased activity of basal adenylate cyclase. The sensitivity of adenylate cyclase to its usual effectors in vitro was not impaired. It is proposed that the lowering of liver cyclic AMP below its basal level after high level section of the spinal cord is due to decreased levels of hepatic catecholamines and/or plasma glucagon. 相似文献
3.
The effect of high level section of the spinal cord upon the hepatic cyclic AMP system was investigated in the rat. We report that transection of the spinal cord dramatically decreases the basal level of cyclic AMP from 0.88 nmol/g liver to 0.36 nmol/g at 1 h and to 0.20 nmol/g at 4 h. This was not due to increased activity of cyclic AMP phosphodiesterase or to decreased activity of basal adenylate cyclase. The sensitivity of adenylate cyclase to its usual effectors in vitro was not impaired. It is proposed that the lowering of liver cyclic AMP below its basal level after high level section of the spinal cord is due to decreased levels of hepatic catecholamines and/or plasma glucagon. 相似文献
4.
L N Egorova T N Nesmeianova A N Trankvillitati 《Biulleten' eksperimental'no? biologii i meditsiny》1979,88(7):15-18
Eight patients with a rupture of the spinal cord at the level of middle thoracic vertebrae or cauda equina at the lumbar level showed partial recovery of motor functions. The development of the activity was revealed by electromyography in body muscles and M. gluteus media in all the patients who attempted voluntary movements. Appearance and development of the activity was also observed in the muscles of the femur and crus. The level of rehabilitation shown by the patients was high enough. They could walk in fixation apparatuses, returned to their occupational activities and could practice self-service. The motor functions recovered more rapidly at the low levels of injury; however, the same and possibly complete rehabilitation was attained in 2 patients with a higher level of injury. The mechanism of the function recovery is underlain by the compensatory development of activity in the muscles of the body and capacity of the distal strip of the spinal cord for elaboration of new motor reactions in which the muscles of the extremities participate. 相似文献
5.
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
6.
N. I. Nezlina 《Neurophysiology》1972,4(5):397-403
Temporal and amplitude characteristics of evoked potentials of the sensomotor cortex in waking cats were studied during variation in the intensity of electrodermal stimulation. The results obtained in experiments on intact animals and on the same animals for several months after division of the spinocervical tracts at the cervical level were compared. After blocking of the inflow of afferent impulses along these tracts of the spinal cord, statistically significant changes in evoked potentials were observed, mainly in response to medium and strong stimulation. These changes were more clear in the motor and second somatosensory areas of the cortex. A decrease in sensitivity to pain also was found. During recovery of the motor functions, cutaneous sensation remained impaired and the amplitude characteristics of the evoked somatosensory activity were not restored. The results suggest that thinner fibers predominate among the primary afferent fibers of the spinocervical tract, and their projections are more widely represented in the second somatosensory and motor areas of the cortex.Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 4, No. 5, pp. 516–523, September–October, 1972. 相似文献
7.
Blagoveshchenskiĭ ED Pettersson LG Perfil'ev SN 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2003,89(9):1058-1066
Cortico- and rubrospinal tracts play an important role in controlling voluntary movements. Transection of these tracts in different spinal cord layers gives different effects that may be explained by the influence of different spinal cord neuronal networks. The aim of the present work was to study the role of C3/C4 propriospinal system in movement control and processes of motor recovery. It was shown that propriospinal system C3/C4 play crucial role in motor recovery after lesion of cortico- and rubrospinal tracts in C5, whereas ventrally located tracts are important after the same lesion in C2. More over, propriospinal system C3/C4 can mediate the command for some voluntary movements in cats. 相似文献
8.
Although spontaneous regeneration of lesioned fibres is limited in the adult central nervous system, many people that suffer from incomplete spinal cord injuries show significant functional recovery. This recovery process can go on for several years after the injury and probably depends on the reorganization of circuits that have been spared by the lesion. Synaptic plasticity in pre-existing pathways and the formation of new circuits through collateral sprouting of lesioned and unlesioned fibres are important components of this recovery process. These reorganization processes might occur in cortical and subcortical motor centres, in the spinal cord below the lesion, and in the spared fibre tracts that connect these centres. Functional and anatomical evidence exists that spontaneous plasticity can be potentiated by activity, as well as by specific experimental manipulations. These studies prepare the way to a better understanding of rehabilitation treatments and to the development of new approaches to treat spinal cord injury. 相似文献
9.
A postmitotic role for Isl-class LIM homeodomain proteins in the assignment of visceral spinal motor neuron identity 总被引:5,自引:0,他引:5
LIM homeobox genes have a prominent role in the regulation of neuronal subtype identity and distinguish motor neuron subclasses in the embryonic spinal cord. We have investigated the role of Isl-class LIM homeodomain proteins in motor neuron diversification using mouse genetic methods. All spinal motor neuron subtypes initially express both Isl1 and Isl2, but Isl2 is rapidly downregulated by visceral motor neurons. Mouse embryos lacking Isl2 function exhibit defects in the migration and axonal projections of thoracic level motor neurons that appear to reflect a cell-autonomous switch from visceral to somatic motor neuron character. Additional genetic mutations that reduce or eliminate both Isl1 and Isl2 activity result in more pronounced defects in visceral motor neuron generation and erode somatic motor neuron character. Thus, an early phase of high Isl expression and activity in newly generated motor neurons permits the diversification of visceral and somatic motor neuron subtypes in the developing spinal cord. 相似文献
10.
Neural cell adhesion molecule (NCAM) regulates tissue organization during development and in the adult. NCAM upregulation occurs after an injury to brains and sciatic nerves. However, little is known about NCAM expression after spinal cord injury (SCI). By using a complete spinal cord transection with a 5 mm tissue removal, an increase in the NCAM level is detected in spinal cord stumps proximal and distal to the transection site at 1 d and 3 d post injury, while its expression at 8 d is declined to a lower level than that observed in sham-operated spinal cords. The strong NCAM expression is present in motor neurons at 3 d post transection whereas the intensive NCAM immunostaining is localized in dorsal sensory and corticospinal fiber tracts at 8 d following injury. Collectively, NCAM level is elevated and strongly expressed in dorsal fiber tracts after SCI, implying that the endogenous process for spinal cord regeneration may take place after SCI. 相似文献
11.
Pelvic floor muscles (PFM) are intimately involved in function of lower urinary tract, the anorectum and sexual functions, therefore their neural control transcends the primarily important somatic innervation of striated muscle, as they are directly involved in “visceral activity”. Neural control of pelvic organs is affected by a unique co-ordination of somatic and autonomic motor nervous systems. Visceral and somatic sensory fibres supply sensory information from pelvic organs; their input influences through central integrative mechanisms also pelvic floor muscle activity. Anatomically, somatic afferent and efferent nerves of the sacral cord segments, reflexly integrated at the spinal cord and brainstem level, conduct neural control of PFM. The inputs from several higher centres influence the complex reflex control and are decisive for voluntary control, and for socially adapted behaviour related to excretory functions. 相似文献
12.
A novel method for simultaneous anterograde and retrograde labeling of spinal cord motor tracts in the same animal. 总被引:3,自引:0,他引:3
E C Tsai R L van Bendegem S W Hwang C H Tator 《The journal of histochemistry and cytochemistry》2001,49(9):1111-1122
Examination of repaired spinal cord tracts has usually required separate groups of animals for anterograde and retrograde tracing owing to the incompatibility of techniques such as tissue fixation. However, anterograde and retrograde labeling of different animals subjected to the same repair may not allow accurate examination of that repair strategy because widely variable results can occur in animals subjected to the same strategy. We have developed a reliable method of labeling spinal cord motor tracts bidirectionally in the same animal using DiI, a lipophilic dye, to anterogradely label the corticospinal tract and Fluoro-Gold (FG) to retrogradely label cortical and brainstem neurons of several spinal cord motor tracts in normal and injured adult rats. Other tracer combinations (lipophilic dyes or fluorescent dextrans) were also investigated but were less effective. We also developed methods to minimize autofluorescence with the DiI/FG technique, and found that the DiI/FG technique is compatible with decalcification and immunohistochemistry for several markers relevant for studies of spinal cord regeneration. Thus, the use of anterograde DiI and retrograde FG is a novel technique for bidirectional labeling of the motor tracts of the adult spinal cord with fluorescent tracers and should be useful for demonstrating neurite regeneration in studies of spinal cord repair.(J Histochem Cytochem 49:1111-1122, 2001) 相似文献
13.
Rossignol S 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2006,361(1473):1647-1671
This review discusses some aspects of plasticity of connections after spinal injury in adult animal models as a basis for functional recovery of locomotion. After reviewing some pitfalls that must be avoided when claiming functional recovery and the importance of a conceptual framework for the control of locomotion, locomotor recovery after spinal lesions, mainly in cats, is summarized. It is concluded that recovery is partly due to plastic changes within the existing spinal locomotor networks. Locomotor training appears to change the excitability of simple reflex pathways as well as more complex circuitry. The spinal cord possesses an intrinsic capacity to adapt to lesions of central tracts or peripheral nerves but, as a rule, adaptation to lesions entails changes at both spinal and supraspinal levels. A brief summary of the spinal capacity of the rat, mouse and human to express spinal locomotor patterns is given, indicating that the concepts derived mainly from work in the cat extend to other adult mammals. It is hoped that some of the issues presented will help to evaluate how plasticity of existing connections may combine with and potentiate treatments designed to promote regeneration to optimize remaining motor functions. 相似文献
14.
The effect of partial and complete spinal cord transection (Th7–Th8) on locomotor activity evoked in decerebrated cats by electrical epidural stimulation (segment L5, 80–100 μA, 0.5 ms at 5 Hz) has been investigated. Transection of dorsal columns did not substantially influence the locomotion. Disruption of the ventral spinal quadrant resulted in deterioration and instability of the locomotor rhythm. Injury to lateral or medial descending motor systems led to redistribution of the tone in antagonist muscles. Locomotion could be evoked by epidural stimulation within 20 h after complete transection of the spinal cord. The restoration of polysynaptic components in EMG responses correlated with recovery of the stepping function. The data obtained confirm that initiation of locomotion under epidural stimulation is caused by direct action on intraspinal systems responsible for locomotor regulation. With intact or partially injured spinal cord, this effect is under the influence of supraspinal motor systems correcting and stabilizing the evoked locomotor pattern. 相似文献
15.
Potentials produced in the frog thalamus by electrical stimulation of the peripheral nerves were investigated by sink and current source-density analysis. Sinks, which are viewed as potential generation sites, were located in three regions: the cell-free zone of the ventral thalamus adjoining the ventrolateral nucleus, the ventromedial and ventrolateral nuclei, and the caudal section of the dorsal thalamus. Evoked activity was recorded in individual neurons in the area of the second and third of these sinks. The first sink failed to form after section of the dorsal tracks of the spinal cord, while the remaining two only appeared after a considerably extended latency. It is suggested that nuclei of the ventral and caudal sections of the dorsal thalamus receive somatic impulses through the systems connected with the dorsal as well as the ventrolateral columns of the spinal cord. The direct projections of the primordial nuclei of dorsal columns may be involved in afferentation the ventral thalamus.I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Translated from Neirofiziologiya, Vol. 18, No. 5, pp. 687–695, September–October, 1986. 相似文献
16.
神经生长因子对兔坐骨神经损伤后脊髓前角运动神经元乙酰胆碱酯酶的影响 总被引:2,自引:0,他引:2
钳夹损伤兔右坐骨神经,于损伤处注射蛇毒NGF400Bu/kg/日,损伤术后1,3,7天和2,3,4,6,8周动态观察脊髓腰段伤侧第Ⅸ板层外侧群的大型运动神经元的AChE活性改变。结果表明术后1,3天实验组(指损伤给药组)和对照组(指损伤对照组)AChE活性均下降(P>005);术后1,2,3周对照组AChE活性明显下降,而实验组AChE活性逐渐趋于恢复(P<001);术后6周实验组AChE活性恢复至正常水平(P<001)。本研究显示蛇毒NGF对坐骨神经损伤后脊髓前角运动神经元AChE活性恢复有促进作用,从而对运动神经元可起一定的保护作用和促进恢复的作用 相似文献
17.
大鼠脊髓不完全性损伤后前角运动神经元的酶细胞化学改变 总被引:6,自引:0,他引:6
以改良Alen氏法造成Wistar大鼠不完全性脊髓损伤,采用神经学功能评分法评定大鼠运动功能,应用定量酶细胞化学方法观察脊髓前角运动神经元内乙酰胆碱酯酶(AChE)和酸性磷酸酶(AcP)活性变化。结果显示:1.脊髓损伤后大鼠运动功能障碍,随后逐渐恢复。2.前角运动神经元内AChE活性减弱、AcP活性增强;随后酶活性呈逐渐恢复,四周时AChE活性基本恢复正常。结果说明:大鼠脊髓不完全性损伤后运动功能变化与前角运动神经元的功能状态具有较强的相关性;前角运动神经元在不完全性脊髓损伤运动功能恢复中起重要作用。 相似文献
18.
Mammals fail in sensory and motor recovery following spinal cord injury due to lack of axonal regrowth below the level of injury as well as an inability to reinitiate spinal neurogenesis. However, some anamniotes including the zebrafish Danio rerio exhibit both sensory and functional recovery even after complete transection of the spinal cord. The adult zebrafish is an established model organism for studying regeneration following spinal cord injury, with sensory and motor recovery by 6 weeks post-injury. To take advantage of in vivo analysis of the regenerative process available in the transparent larval zebrafish as well as genetic tools not accessible in the adult, we use the larval zebrafish to study regeneration after spinal cord transection. Here we demonstrate a method for reproducibly and verifiably transecting the larval spinal cord. After transection, our data shows sensory recovery beginning at 2 days post-injury (dpi), with the C-bend movement detectable by 3 dpi and resumption of free swimming by 5 dpi. Thus we propose the larval zebrafish as a companion tool to the adult zebrafish for the study of recovery after spinal cord injury. 相似文献
19.
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
20.
T N Nesmeianova 《Biulleten' eksperimental'no? biologii i meditsiny》1975,80(10):25-29
There was revealed a possibility of making a more precise diagnosis of the extent of the spinal cord trauma with the aid of electromyography, even at the early period of treatment. The following indices revealed on the attempt to move indicated the absence of anatomical section of the spinal cord: 1) with the level of the trauma at D5--D10 the absence of retardation in time of inclusion into the activity of the lower portions of the long muscles of the body in comparison with their upper portions; 2) with the level of the trauma at D10--L5--L1--the presence of the activity in the muscles of the hip and the shin recorded even in the form of individual potentials of low amplitude; 3) irrespective of the level of the trauma, the appearance of the activity in the symmetrical muscles of one foot on the attempt to move the other one. Even in the presence of one positive index the motor functions were restored in the majority of the patients by the restitution type. 相似文献