3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-cycloastragenol （astragaloside IV）, the main active component of the traditional Chinese medicine astragalus membranaceus, has been shown to be neuroprotective. Thi...3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-cycloastragenol （astragaloside IV）, the main active component of the traditional Chinese medicine astragalus membranaceus, has been shown to be neuroprotective. This study investigated whether astragaloside IV could promote the repair of injured sciatic nerve. Denervated sciatic nerve of mice was subjected to anastomosis. The mice were intraperitoneally injected with 10, 5, 2.5 mg/kg astragaloside IV per day for 8 consecutive days Western blot assay and real-time PCR results demonstrated that growth-associated protein-43 ex- pression was upregulated in mouse spinal cord segments L4-6 after intervention with 10, 5, 2.5 mg/kg astragaloside IV per day in a dose-dependent manner. Luxol fast blue staining and elec- trophysiological detection suggested that astragaloside IV elevated the number and diameter of myelinated nerve fibers, and simultaneously increased motor nerve conduction velocity and action potential amplitude in the sciatic nerve of mice. These results indicated that astragaloside IV con- tributed to sciatic nerve regeneration and functional recovery in mice. The mechanism underlying this effect may be associated with the upregulation of growth-associated protein-43 expression.展开更多
The contactin-associated protein （Caspr） family participates in nerve excitation and conduction, and neurotransmitter release in myelinated axons. We analyzed the structures and functions of the Caspr family- CNTNA...The contactin-associated protein （Caspr） family participates in nerve excitation and conduction, and neurotransmitter release in myelinated axons. We analyzed the structures and functions of the Caspr family- CNTNAP1 （Casprl）, CNTNAP2 （Caspr2）, CNTNAP3 （Caspr3）, CNTNAP4 （Caspr4） and CNTNAP5 （Caspr5）, Casprl-5 is not only involved in the formation of myelinated axons, but also participates in maintaining the stability of adjacent connections. Casprl participates in the formation, differentiation, and proliferation of neurons and astrocytes, and in motor control and cognitive function. We also analyzed the relationship between the Caspr family and neurodegenerative diseases, multiple sclerosis, and autoimmune encephalitis. However, the effects of Caspr on disease course and prognosis remain poorly understood. The effects of Caspr on disease diagnosis and treatment need further investigation.展开更多
Although neurophysiological and psychophysical proof of osseoperception is accumulating, histomorphometric evidence for the neural mechanisms of functional compensation following immediate and delayed implant loading ...Although neurophysiological and psychophysical proof of osseoperception is accumulating, histomorphometric evidence for the neural mechanisms of functional compensation following immediate and delayed implant loading is still lacking. For this randomized split-mouth study, six mongrel dogs randomly received one of four treatment protocols at 36 implant-recipient sites over 16 weeks （third maxillary incisor, third and fourth mandibular premolar）： immediate implant placement and immediate loading （liP＋ IL）; delayed implant placement and delayed loading （DIP＋DL）; delayed implant placement and immediate loading （DIP＋IL）; and natural extraction socket healing （control）. Histomorphometry was performed in the peri-implant bone and soft tissues within 300 pm around the implants. Immunocytochemistry and transmission electron microscopy were used to confirm the presence of neural structures and to reveal their ultrastructural characteristics, respectively. Myelinated nerve fibres densely populated the peri-implant crestal gingival and apical regions, although they were also identified in the woven bone and in the osteons near the implant threads. Compared with the control group in the mandible, the group that received IIP＋IL showed a higher innervation （in N.mm^-2, 5.94±1.12 vs. 3.15±0.63, P〈0.001） and smaller fibre diameter （in pm, 1.37±0.05 vs. 1.64±0.13, P=0.016）, smaller axon diameter （in pm, 0.89±0.05 vs. 1.24±0,10, P=0.009） and g-ratio （0.64±0.04 vs. 0.76±0.05, P〈0.001） in the middle region around the implants. Compared with DIP＋IL in the mandible, IIP＋IL had a higher nerve density （in N.mm^-2, 13.23±2.54 vs. 9.64±1.86, P=0.027）, greater fibre diameter （in pm, 1.32±0.02 vs. 1.20±0.04, P=0.021）, greater axon diameter （in μm, 0.92±0.01 vs. 0.89±0.03, P=-0.035） and lower g-ratio （0.69±0.01 vs. 0.74±0.01, P=-0.033） in the apical region around the implants. It may be assumed that the treatment protocol with liP＋ IL is the preferred me展开更多
Platelet-rich plasma containing various growth factors can promote nerve regeneration. An inside-out vein graft can substitute nerve autograft to repair short nerve defects. It is hypothesized that an inside-out vein ...Platelet-rich plasma containing various growth factors can promote nerve regeneration. An inside-out vein graft can substitute nerve autograft to repair short nerve defects. It is hypothesized that an inside-out vein graft filled with platelet-rich plasma shows better effects in the repair of short sciatic nerve defects. In this study, an inside-out vein autograft filled with platelet-rich plasma was used to bridge a 10 mm-long sciatic nerve defect in rats. The sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better improved than that of rats with a simple inside-out vein autograft. At 6 and 8 weeks, the sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better than that of rats undergoing nerve autografting. Compared with the sciatic nerve repaired with a simple inside-out vein autograft, the number of myelinated axons was higher, axon diameter and myelin sheath were greater in the sciatic nerve repaired with an inside-out vein autograft filled with plateletrich plasma and they were similar to those in the sciatic nerve repaired with nerve autograft. These findings suggest that an inside-out vein graft filled with platelet-rich plasma can substitute nerve autograft to repair short sciatic nerve defects.展开更多
The repair of peripheral nerve injury after complete amputation is difficult,and even with anastomosis,the rapid recovery of nerve function remains challenging.Curcumin,extracted from plants of the genus Curcuma,has b...The repair of peripheral nerve injury after complete amputation is difficult,and even with anastomosis,the rapid recovery of nerve function remains challenging.Curcumin,extracted from plants of the genus Curcuma,has been shown to have anti-oxidant and anti-inflammatory properties and to improve sciatic nerve crush injury in rats.Here,we determined whether curcumin had neuroprotective effects following complete peripheral nerve amputation injury.BALB/c mice underwent complete sciatic nerve amputation,followed by an immediate epineurium anastomosis.Mice were intragastrically administered curcumin at doses of 40（high）,20（moderate）,and 10 mg/kg/d（low） for 1 week.We found that myelin in the mice of the high- and moderate-dose curcumin groups appeared with regular shape,uniform thickness,clear boundary,and little hyperplasia surrounding the myelin.High and moderate doses of curcumin markedly improved both action potential amplitude of the sciatic nerves and the conduction velocity of the corresponding motor neurons,and upregulated m RNA and protein expression of S100,a marker for Schwann cell proliferation,in L4–6 spinal cord segments.These results suggest that curcumin is effective in promoting the repair of complete sciatic nerve amputation injury and that the underlying mechanism may be associated with upregulation of S100 expression.展开更多
Repetitive magnetic stimulation is effective for treating posttraumatic neuropathies following spinal or axonal injury.Neurotropin is a potential treatment for nerve injuries like demyelinating diseases.This study sou...Repetitive magnetic stimulation is effective for treating posttraumatic neuropathies following spinal or axonal injury.Neurotropin is a potential treatment for nerve injuries like demyelinating diseases.This study sought to observe the effects of high-frequency repetitive magnetic stimulation,neurotropin and their combined use in the treatment of peripheral nerve injury in 32 adult male Sprague-Dawley rats.To create a sciatic nerve injury model,a 10 mm-nerve segment of the left sciatic nerve was cut and rotated through 180°and each end restored continuously with interrupted sutures.The rats were randomly divided into four groups.The control group received only a reversed autograft in the left sciatic nerve with no treatment.In the high-frequency repetitive magnetic stimulation group,peripheral high-frequency repetitive magnetic stimulation treatment(20 Hz,20 min/d)was delivered for 10 consecutive days after auto-grafting.In the neurotropin group,neurotropin therapy(0.96 NU/kg per day)was administrated for 10 consecutive days after surgery.In the combined group,the combination of peripheral high-frequency repetitive magnetic stimulation(20 Hz,20 min/d)and neurotropin(0.96 NU/kg per day)was given for 10 consecutive days after the operation.The Basso-Beattie-Bresnahan locomotor rating scale was used to assess the behavioral recovery of the injured nerve.The sciatic functional index was used to evaluate the recovery of motor functions.Toluidine blue staining was performed to determine the number of myelinated fibers in the distal and proximal grafts.Immunohistochemistry staining was used to detect the length of axons marked by neurofilament 200.Our results reveal that the Basso-Beattie-Bresnahan locomotor rating scale scores,sciatic functional index,the number of myelinated fibers in distal and proximal grafts were higher and axon lengths were longer in the high-frequency repetitive magnetic stimulation,neurotropin and combined groups compared with the control group.These measures were not significantly different am展开更多
Purpose: To show epidemiological and imaging aspects of congenital optic disc abnormalities diagnosed late. Method: It was a retrospective study, including all patients with congenital optic disc abnormalities diagnos...Purpose: To show epidemiological and imaging aspects of congenital optic disc abnormalities diagnosed late. Method: It was a retrospective study, including all patients with congenital optic disc abnormalities diagnosed at a late age between January 2020 and October 2022 at the eye center of Abass Ndao Hospital. Complete ophthalmological examination was performed with eye imaging according to the cases. Results: 09 patients (10 eyes) were diagnosed with congenital optic disc abnormalities. The mean age was 29 years, with a sex ratio of 0.8. Three patients had consulted for unilateral decreased visual acuity since childhood, two for sudden vision loss and in four cases the diagnosis was fortuitous. Visual acuity was ranged from 1/200 to 20/20. Fundus examination showed myelinated retinal nerve fibers in four eyes, optic disc pit in three eyes including two complicated by maculopathy, two cases of morning glory syndrome and a case of pseudoduplication of the optic disc. Optical coherence tomography, ocular ultrasound B and OCT-Angiography were performed according to the cases. Conclusion: Congenital optic disc abnormalities are often diagnosed late. They are potentially amblyogenic and complications are not rare, worsening the visual prognosis. Their screening should be systematic by ophthalmological examination in newborns.展开更多
An animal model of cortical dysplasia was established through X-ray irradiation induced subcortical heterotopic nodules in rats. Transmission electron microscopy detection of the ultrastructure and the stereology exam...An animal model of cortical dysplasia was established through X-ray irradiation induced subcortical heterotopic nodules in rats. Transmission electron microscopy detection of the ultrastructure and the stereology examination showed that there was a significant decrease in cerebral white matter and hippocampal volume, the total volume, volume density, length density and total length of the myelinated fibers in the white matter of cortical dysplasia rats. Subcortical heterotopic nodules of the hippocampal CA1 region and synaptic number density in the CA3 region were reduced compared with normal rats. Our experimental findings indicate that erosed subcortical heterotopic nodules, decreased total length of myelinated nerve fibers and demyelination directly lead to a reduction of white matter volume.展开更多
A sciatic nerve transection and repair model was established in Sprague-Dawley rats by transecting the tendon of obturator internus muscle in the greater sciatic foramen and suturing with nylon sutures. The models wer...A sciatic nerve transection and repair model was established in Sprague-Dawley rats by transecting the tendon of obturator internus muscle in the greater sciatic foramen and suturing with nylon sutures. The models were treated with tacrolimus gavage （4 mg/kg per day） for 0, 2, 4 and 6 weeks. Specimens were harvested at 6 weeks of intragastric administration. Masson staining revealed that the collagen fiber content and scar area in the nerve anastomosis of the sciatic nerve injury rats were significantly reduced after tacrolimus administration. Hematoxylin-eosin staining showed that tacrolimus significantly increased myelinated nerve fiber density, average axon diameter and myelin sheath thickness. Intragastric administration of tacrolimus also led to a significant increase in the recovery rate of gastrocnemius muscle wet weight and the sciatic functional index after sciatic nerve injury. The above indices were most significantly improved at 6 weeks after of tacrolimus gavage. The myelinated nerve fiber density in the nerve anastomosis and the sciatic nerve functions had a significant negative correlation with the scar area, as detected by Spearman＇s rank correlation analysis. These findings indicate that tacrolimus can promote peripheral nerve regeneration and accelerate the recovery of neurological function through the reduction of scar formation.展开更多
Until now, nerve conduction has been described on the basis of equivalent circuit model and cable theory, both of which supposed closed electric circuits spreading inside and outside the axoplasm. With these conventio...Until now, nerve conduction has been described on the basis of equivalent circuit model and cable theory, both of which supposed closed electric circuits spreading inside and outside the axoplasm. With these conventional models, we can simulate the propagating pattern of action potential along the axonal membrane based on Ohm＇s law and Kirchhoff＇s law. However, we could not fully explain the different conductive patterns in unmyelinated and myelinated nerves with these theories. Also, whether we can really suppose closed electrical circuits in the actual site of the nerves or not has not been fully discussed yet. In this report, a recently introduced new theoretical model of nerve conduction based on electrostatic molecular interactions within the axoplasm will be reviewed. With this new approach, we can explain the different conductive patterns in unmyelinated and myelinated nerves. This new mathematical conductive model based on electrostatic compressional wave in the intracellular fluid may also be able to explain the signal integration in the neuronal cell body and the back-propagation mechanism from the axons to the dendrites. With this new mathematical nerve conduction model based on electrostatic molecular interactions within the intracellular fluid, we may be able to achieve an integrated explanation for the physiological phenomena taking place in the nervous system.展开更多
We systematically study the evolution of modulated nerve impulses in a myelinated nerve fiber, where both the ionic current and membrane capacitance provide the necessary nonlinear feedbacks. This is achieved by using...We systematically study the evolution of modulated nerve impulses in a myelinated nerve fiber, where both the ionic current and membrane capacitance provide the necessary nonlinear feedbacks. This is achieved by using a perturbation technique, in which the Liénard form of the modified discrete Fitzhugh–Nagumo equation is reduced to the complex Ginzburg–Landau amplitude equation. Three distinct values of the capacitive feedback parameter are considered. At the critical value of the capacitive feedback parameter, it is shown that the dynamics of the system is governed by the dissipative nonlinear Schr?dinger equation. Linear stability analysis of the system depicts the instability of plane waves,which is manifested as burst of modulated nerve impulses that fulfills the Benjamin–Feir criteria. Variations of the capacitive feedback parameter generally influences the plane wave stability and hence the type of wave profile identified in the neural network. Results of numerical simulations mainly confirm the propagation, collision, and annihilation of nerve impulses in the myelinated axon.展开更多
Neurological signs and segmcntal demyelination in a cervical nerve were observed in rats treated orally with permethrin (300 mg/kg/day) for 5 days. Inflammatory and degenerative signals were recorded in the diaphragm... Neurological signs and segmcntal demyelination in a cervical nerve were observed in rats treated orally with permethrin (300 mg/kg/day) for 5 days. Inflammatory and degenerative signals were recorded in the diaphragm muscle. These effects were more intense with the trade grade than with the technical grade product. The possible influence of the percentage of cisitrans isomers on the intensity of the observed effects is discussed. 5 imi Academic Press.Inc.展开更多
Dear Sir,I write to present the correlation between microperimetric （MP） values and the density of myelinated retinal nerve fibers （MNFs） in optical coherence tomography （OCT） imaging.
Based on our previous work, we study the problem of neural signal transmission of myelinated neurons. We found that the transmembrane ion current at Ranvier's node acts as an energy supplement. In addition, the le...Based on our previous work, we study the problem of neural signal transmission of myelinated neurons. We found that the transmembrane ion current at Ranvier's node acts as an energy supplement. In addition, the length of the myelin sheath has an upper limit of lT. Above this upper limit, the neural signal will not be effectively transmitted. In the range of normal physiological parameters, lT is on the order of mm. Finally, the effect of temperature on the transmission of nerve signals is investigated. temperatures that are too high and too low are not conducive to the conduction of nerve signals.展开更多
文摘3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-cycloastragenol （astragaloside IV）, the main active component of the traditional Chinese medicine astragalus membranaceus, has been shown to be neuroprotective. This study investigated whether astragaloside IV could promote the repair of injured sciatic nerve. Denervated sciatic nerve of mice was subjected to anastomosis. The mice were intraperitoneally injected with 10, 5, 2.5 mg/kg astragaloside IV per day for 8 consecutive days Western blot assay and real-time PCR results demonstrated that growth-associated protein-43 ex- pression was upregulated in mouse spinal cord segments L4-6 after intervention with 10, 5, 2.5 mg/kg astragaloside IV per day in a dose-dependent manner. Luxol fast blue staining and elec- trophysiological detection suggested that astragaloside IV elevated the number and diameter of myelinated nerve fibers, and simultaneously increased motor nerve conduction velocity and action potential amplitude in the sciatic nerve of mice. These results indicated that astragaloside IV con- tributed to sciatic nerve regeneration and functional recovery in mice. The mechanism underlying this effect may be associated with the upregulation of growth-associated protein-43 expression.
基金supported by a grant from the Instructional Program of Science and Technology Bureau of Wuxi City of China,No.0302B010507130039PB
文摘The contactin-associated protein （Caspr） family participates in nerve excitation and conduction, and neurotransmitter release in myelinated axons. We analyzed the structures and functions of the Caspr family- CNTNAP1 （Casprl）, CNTNAP2 （Caspr2）, CNTNAP3 （Caspr3）, CNTNAP4 （Caspr4） and CNTNAP5 （Caspr5）, Casprl-5 is not only involved in the formation of myelinated axons, but also participates in maintaining the stability of adjacent connections. Casprl participates in the formation, differentiation, and proliferation of neurons and astrocytes, and in motor control and cognitive function. We also analyzed the relationship between the Caspr family and neurodegenerative diseases, multiple sclerosis, and autoimmune encephalitis. However, the effects of Caspr on disease course and prognosis remain poorly understood. The effects of Caspr on disease diagnosis and treatment need further investigation.
基金supported by the Natural Science Foundation of China (81000459)the Chinese Scholarship Council
文摘Although neurophysiological and psychophysical proof of osseoperception is accumulating, histomorphometric evidence for the neural mechanisms of functional compensation following immediate and delayed implant loading is still lacking. For this randomized split-mouth study, six mongrel dogs randomly received one of four treatment protocols at 36 implant-recipient sites over 16 weeks （third maxillary incisor, third and fourth mandibular premolar）： immediate implant placement and immediate loading （liP＋ IL）; delayed implant placement and delayed loading （DIP＋DL）; delayed implant placement and immediate loading （DIP＋IL）; and natural extraction socket healing （control）. Histomorphometry was performed in the peri-implant bone and soft tissues within 300 pm around the implants. Immunocytochemistry and transmission electron microscopy were used to confirm the presence of neural structures and to reveal their ultrastructural characteristics, respectively. Myelinated nerve fibres densely populated the peri-implant crestal gingival and apical regions, although they were also identified in the woven bone and in the osteons near the implant threads. Compared with the control group in the mandible, the group that received IIP＋IL showed a higher innervation （in N.mm^-2, 5.94±1.12 vs. 3.15±0.63, P〈0.001） and smaller fibre diameter （in pm, 1.37±0.05 vs. 1.64±0.13, P=0.016）, smaller axon diameter （in pm, 0.89±0.05 vs. 1.24±0,10, P=0.009） and g-ratio （0.64±0.04 vs. 0.76±0.05, P〈0.001） in the middle region around the implants. Compared with DIP＋IL in the mandible, IIP＋IL had a higher nerve density （in N.mm^-2, 13.23±2.54 vs. 9.64±1.86, P=0.027）, greater fibre diameter （in pm, 1.32±0.02 vs. 1.20±0.04, P=0.021）, greater axon diameter （in μm, 0.92±0.01 vs. 0.89±0.03, P=-0.035） and lower g-ratio （0.69±0.01 vs. 0.74±0.01, P=-0.033） in the apical region around the implants. It may be assumed that the treatment protocol with liP＋ IL is the preferred me
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology,No.2011-0010429
文摘Platelet-rich plasma containing various growth factors can promote nerve regeneration. An inside-out vein graft can substitute nerve autograft to repair short nerve defects. It is hypothesized that an inside-out vein graft filled with platelet-rich plasma shows better effects in the repair of short sciatic nerve defects. In this study, an inside-out vein autograft filled with platelet-rich plasma was used to bridge a 10 mm-long sciatic nerve defect in rats. The sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better improved than that of rats with a simple inside-out vein autograft. At 6 and 8 weeks, the sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better than that of rats undergoing nerve autografting. Compared with the sciatic nerve repaired with a simple inside-out vein autograft, the number of myelinated axons was higher, axon diameter and myelin sheath were greater in the sciatic nerve repaired with an inside-out vein autograft filled with plateletrich plasma and they were similar to those in the sciatic nerve repaired with nerve autograft. These findings suggest that an inside-out vein graft filled with platelet-rich plasma can substitute nerve autograft to repair short sciatic nerve defects.
基金supported by the Jilin Provincial Science & Technology Development Project Fund of China,No.20150311038YY
文摘The repair of peripheral nerve injury after complete amputation is difficult,and even with anastomosis,the rapid recovery of nerve function remains challenging.Curcumin,extracted from plants of the genus Curcuma,has been shown to have anti-oxidant and anti-inflammatory properties and to improve sciatic nerve crush injury in rats.Here,we determined whether curcumin had neuroprotective effects following complete peripheral nerve amputation injury.BALB/c mice underwent complete sciatic nerve amputation,followed by an immediate epineurium anastomosis.Mice were intragastrically administered curcumin at doses of 40（high）,20（moderate）,and 10 mg/kg/d（low） for 1 week.We found that myelin in the mice of the high- and moderate-dose curcumin groups appeared with regular shape,uniform thickness,clear boundary,and little hyperplasia surrounding the myelin.High and moderate doses of curcumin markedly improved both action potential amplitude of the sciatic nerves and the conduction velocity of the corresponding motor neurons,and upregulated m RNA and protein expression of S100,a marker for Schwann cell proliferation,in L4–6 spinal cord segments.These results suggest that curcumin is effective in promoting the repair of complete sciatic nerve amputation injury and that the underlying mechanism may be associated with upregulation of S100 expression.
基金funded by the National Natural Science Foundation of China,No.81471338 and No.81671284(to XJZ)the Changzhou Science&Technology Program of China,No.CE20145045(to XJZ)the Changzhou High-Level Medical Talents Training Project of China,No.2016CZLJ018(to XJZ)
文摘Repetitive magnetic stimulation is effective for treating posttraumatic neuropathies following spinal or axonal injury.Neurotropin is a potential treatment for nerve injuries like demyelinating diseases.This study sought to observe the effects of high-frequency repetitive magnetic stimulation,neurotropin and their combined use in the treatment of peripheral nerve injury in 32 adult male Sprague-Dawley rats.To create a sciatic nerve injury model,a 10 mm-nerve segment of the left sciatic nerve was cut and rotated through 180°and each end restored continuously with interrupted sutures.The rats were randomly divided into four groups.The control group received only a reversed autograft in the left sciatic nerve with no treatment.In the high-frequency repetitive magnetic stimulation group,peripheral high-frequency repetitive magnetic stimulation treatment(20 Hz,20 min/d)was delivered for 10 consecutive days after auto-grafting.In the neurotropin group,neurotropin therapy(0.96 NU/kg per day)was administrated for 10 consecutive days after surgery.In the combined group,the combination of peripheral high-frequency repetitive magnetic stimulation(20 Hz,20 min/d)and neurotropin(0.96 NU/kg per day)was given for 10 consecutive days after the operation.The Basso-Beattie-Bresnahan locomotor rating scale was used to assess the behavioral recovery of the injured nerve.The sciatic functional index was used to evaluate the recovery of motor functions.Toluidine blue staining was performed to determine the number of myelinated fibers in the distal and proximal grafts.Immunohistochemistry staining was used to detect the length of axons marked by neurofilament 200.Our results reveal that the Basso-Beattie-Bresnahan locomotor rating scale scores,sciatic functional index,the number of myelinated fibers in distal and proximal grafts were higher and axon lengths were longer in the high-frequency repetitive magnetic stimulation,neurotropin and combined groups compared with the control group.These measures were not significantly different am
文摘Purpose: To show epidemiological and imaging aspects of congenital optic disc abnormalities diagnosed late. Method: It was a retrospective study, including all patients with congenital optic disc abnormalities diagnosed at a late age between January 2020 and October 2022 at the eye center of Abass Ndao Hospital. Complete ophthalmological examination was performed with eye imaging according to the cases. Results: 09 patients (10 eyes) were diagnosed with congenital optic disc abnormalities. The mean age was 29 years, with a sex ratio of 0.8. Three patients had consulted for unilateral decreased visual acuity since childhood, two for sudden vision loss and in four cases the diagnosis was fortuitous. Visual acuity was ranged from 1/200 to 20/20. Fundus examination showed myelinated retinal nerve fibers in four eyes, optic disc pit in three eyes including two complicated by maculopathy, two cases of morning glory syndrome and a case of pseudoduplication of the optic disc. Optical coherence tomography, ocular ultrasound B and OCT-Angiography were performed according to the cases. Conclusion: Congenital optic disc abnormalities are often diagnosed late. They are potentially amblyogenic and complications are not rare, worsening the visual prognosis. Their screening should be systematic by ophthalmological examination in newborns.
基金supported by Talent Foundation of the Affiliated Hospital of Luzhou Medical College, No. 09057Youth Researcher Foundation of Luzhou Medical College, No. 09013+2 种基金Key Program of the Education Department of Sichuan Province, No. 09ZA046Scientific Research Foundation of the Health Department of Sichuan Province, No. 090231a grant from Science and Technology Bureau of Luzhou, No. (2009)1
文摘An animal model of cortical dysplasia was established through X-ray irradiation induced subcortical heterotopic nodules in rats. Transmission electron microscopy detection of the ultrastructure and the stereology examination showed that there was a significant decrease in cerebral white matter and hippocampal volume, the total volume, volume density, length density and total length of the myelinated fibers in the white matter of cortical dysplasia rats. Subcortical heterotopic nodules of the hippocampal CA1 region and synaptic number density in the CA3 region were reduced compared with normal rats. Our experimental findings indicate that erosed subcortical heterotopic nodules, decreased total length of myelinated nerve fibers and demyelination directly lead to a reduction of white matter volume.
基金supported by the National Natural Science Foundation of China, No. 81171694
文摘A sciatic nerve transection and repair model was established in Sprague-Dawley rats by transecting the tendon of obturator internus muscle in the greater sciatic foramen and suturing with nylon sutures. The models were treated with tacrolimus gavage （4 mg/kg per day） for 0, 2, 4 and 6 weeks. Specimens were harvested at 6 weeks of intragastric administration. Masson staining revealed that the collagen fiber content and scar area in the nerve anastomosis of the sciatic nerve injury rats were significantly reduced after tacrolimus administration. Hematoxylin-eosin staining showed that tacrolimus significantly increased myelinated nerve fiber density, average axon diameter and myelin sheath thickness. Intragastric administration of tacrolimus also led to a significant increase in the recovery rate of gastrocnemius muscle wet weight and the sciatic functional index after sciatic nerve injury. The above indices were most significantly improved at 6 weeks after of tacrolimus gavage. The myelinated nerve fiber density in the nerve anastomosis and the sciatic nerve functions had a significant negative correlation with the scar area, as detected by Spearman＇s rank correlation analysis. These findings indicate that tacrolimus can promote peripheral nerve regeneration and accelerate the recovery of neurological function through the reduction of scar formation.
文摘Until now, nerve conduction has been described on the basis of equivalent circuit model and cable theory, both of which supposed closed electric circuits spreading inside and outside the axoplasm. With these conventional models, we can simulate the propagating pattern of action potential along the axonal membrane based on Ohm＇s law and Kirchhoff＇s law. However, we could not fully explain the different conductive patterns in unmyelinated and myelinated nerves with these theories. Also, whether we can really suppose closed electrical circuits in the actual site of the nerves or not has not been fully discussed yet. In this report, a recently introduced new theoretical model of nerve conduction based on electrostatic molecular interactions within the axoplasm will be reviewed. With this new approach, we can explain the different conductive patterns in unmyelinated and myelinated nerves. This new mathematical conductive model based on electrostatic compressional wave in the intracellular fluid may also be able to explain the signal integration in the neuronal cell body and the back-propagation mechanism from the axons to the dendrites. With this new mathematical nerve conduction model based on electrostatic molecular interactions within the intracellular fluid, we may be able to achieve an integrated explanation for the physiological phenomena taking place in the nervous system.
文摘We systematically study the evolution of modulated nerve impulses in a myelinated nerve fiber, where both the ionic current and membrane capacitance provide the necessary nonlinear feedbacks. This is achieved by using a perturbation technique, in which the Liénard form of the modified discrete Fitzhugh–Nagumo equation is reduced to the complex Ginzburg–Landau amplitude equation. Three distinct values of the capacitive feedback parameter are considered. At the critical value of the capacitive feedback parameter, it is shown that the dynamics of the system is governed by the dissipative nonlinear Schr?dinger equation. Linear stability analysis of the system depicts the instability of plane waves,which is manifested as burst of modulated nerve impulses that fulfills the Benjamin–Feir criteria. Variations of the capacitive feedback parameter generally influences the plane wave stability and hence the type of wave profile identified in the neural network. Results of numerical simulations mainly confirm the propagation, collision, and annihilation of nerve impulses in the myelinated axon.
文摘 Neurological signs and segmcntal demyelination in a cervical nerve were observed in rats treated orally with permethrin (300 mg/kg/day) for 5 days. Inflammatory and degenerative signals were recorded in the diaphragm muscle. These effects were more intense with the trade grade than with the technical grade product. The possible influence of the percentage of cisitrans isomers on the intensity of the observed effects is discussed. 5 imi Academic Press.Inc.
基金Supported by the Korean Ministry of Environment through"The Environmental Health Action Program",Korea(No.2012001350010)Korea University(No.K1400629)
文摘Dear Sir,I write to present the correlation between microperimetric （MP） values and the density of myelinated retinal nerve fibers （MNFs） in optical coherence tomography （OCT） imaging.
基金Project supported in part by the National Defense Technology Innovation Special Zonethe National Natural Science Foundation of China(Grant Nos.51677145 and 11622542)。
文摘Based on our previous work, we study the problem of neural signal transmission of myelinated neurons. We found that the transmembrane ion current at Ranvier's node acts as an energy supplement. In addition, the length of the myelin sheath has an upper limit of lT. Above this upper limit, the neural signal will not be effectively transmitted. In the range of normal physiological parameters, lT is on the order of mm. Finally, the effect of temperature on the transmission of nerve signals is investigated. temperatures that are too high and too low are not conducive to the conduction of nerve signals.
