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Persistent neurogenesis exists in the subventricular zone (SVZ) of the ventricles and the subgranular zone (SGZ) of the dentate gyrus of the hippocampus in the adult mammalian brain. Adult endogenous neurogenesis not only plays an important role in the normal brain function, but also has important significance in the repair and treatment of brain injury or brain diseases. This article reviews the process of adult endogenous neurogenesis and its application in the repair of traumatic brain injury (TBI) or ischemic stroke, and discusses the strategies of activating adult endogenous neurogenesis to repair brain injury and its practical significance in promoting functional recovery after brain injury.
Subject(s)
Adult , Animals , Humans , Brain/physiopathology , Hippocampus/physiopathology , Mammals/physiology , Neurogenesis/physiology , Brain Hemorrhage, Traumatic/therapy , Ischemic Stroke/therapy , Recovery of Function , Spinal Cord/physiopathologyABSTRACT
Muscle spindle is the key proprioceptor in skeletal muscles and plays important roles in many physiological activities, such as maintaining posture, regulating movement and controlling speed variation. It has significant clinical relevance and is emerging as a promising therapeutic target for the treatment of motor functional impairment and metabolic diseases. In this review, we summarized muscle spindle distribution and the mechanism of mechanical signal transmission, and reviewed the research progress on morphological and structural characteristics of muscle spindles.
Subject(s)
Muscle Spindles/physiology , Muscle, Skeletal/physiology , Clinical RelevanceABSTRACT
Objective:To evaluate the residual stepping ability in monkeys with spinal cord injury longitudinally. Methods:Four adult female monkeys were studied. Right hemisection of 10 mm spinal cord tissue was performed at the T7-9 segment. Gait tests of bipedal locomotion were performed before, and six weeks and twelve weeks after injury by VICON system. Gait cycle duration, amplitude of knee and ankle angles, and ratio of united parameters were obtained from successive stepping and were quantitative analyzed. Results:The coordination of bilateral hindlimbs was destroyed after spinal cord injury, and the right hindlimb showed obviously dragging. The gait cycle duration of the left hindlimb increased significantly (P < 0.001), and the amplitudes of knee and ankle angle significantly increased (P < 0.001) after spinal cord injury. The ratio of united parameters was not statistically different among all the time points (P > 0.05). The gait cycle duration of the left hindlimb was correlated with step length (r = 0.838, P = 0.001), step height (r = 0.726, P = 0.007) and amplitude of ankle angle (r = 0.766, P = 0.004), and the amplitude of ankle angle was correlated with step length (r = 0.627, P = 0.029). Conclusion:The gait pattern of monkey with spinal cord injury has been changed. The gait strategy of the uninjured side was adjusted compensatively after spinal cord injury to adapt the functional impairment of contralateral hindlimb.
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BACKGROUND: Either good biocompatibility and biological activity of active biological materials or the potential of multidirectional differentiation of neural stem cells has great application prospect and value. OBJECTIVE: To investigate the effect of neurotrophic factor 3-chitosan active biomaterial scaffolds on the differentiation of neural stem cells and the expression of key proteins of the neurotrophic factor 3 signal pathway in vitro. METHODS: The neural stem cells were extracted and purified, and then divided into pure culture medium group, soluble neurotrophic factor 3 group, pure chitosan group, and neurotrophic factor 3-chitosan group for differentiation induction. The expression of TrkC, Akt / p-Akt and Erk/p-Erk in the neurotrophic factor 3 signaling pathway was detected by western blot after 6 hours of induction. After 7 days of induction, differentiation of neural stem cells was observed by immunocytochemistry of MAP2, MBP, and GFAP. After 14 days of induction, formation of neural network induced by neurotrophic factor 3-chitosan active biomaterials was observed by immunocytochemistry of MAP2, Synapsin-1, and PSD95. RESULTS AND CONCLUSION: The neurotrophic factor 3-chitosan group induced a high proportion of neural stem cells differentiated into neurons, with a ratio of 73.8%, which was significantly higher than that in the other three groups. Meanwhile, the proportion of cells differentiated into glial cells waslower than that in the other three groups. The expression of key proteins TrkC, p-Akt and p-Erk in the neurotrophic factor 3-chitosan group was higher than that in the other three groups. Meanwhile, neurotrophic factor 3-chitosan could induce the in vitro differentiation of neural stem cells to form neural network.
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The present study was aimed to investigate the electrophysiological characteristics of hippocampal postnatal early development mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in rats. Forty-eight Wistar rats were divided into postnatal 0.5-, 1-, 2- and 3-month groups (n = 12). Spontaneous excitatory postsynaptic currents (sEPSCs) and field excitatory postsynaptic potentials (fEPSPs) mediated by AMPA receptors were recorded to evaluate the changes in the intrinsic membrane properties of hippocampal CA1 pyramidal neurons by using patch-clamp and MED64 planar microelectrode array technique respectively. The results showed that, during the period of postnatal 0.5-3 months, some of the intrinsic membrane properties of hippocampal CA1 pyramidal neurons, such as the membrane capacitance (Cm) and the resting membrane potential (RMP), showed no significant changes, while the membrane input resistance (Rin) and the time constant (τ) of the cells were decreased significantly. The amplitude, frequency and kinetics (both rise and decay times) of sEPSCs were significantly increased during the period of postnatal 0.5-1 month, but they were all decreased during the period of postnatal 1-3 months. In addition, the range of evoked fEPSPs in hippocamal CA1 region was significantly expanded, but the fEPSP amplitudes were decreased significantly during the period of postnatal 0.5-3 months. Furthermore, the evoked fEPSPs could be significantly inhibited by extracellular application of the AMPA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). These results suggest that AMPA receptor may act as a major type of excitatory receptor to regulate synaptic transmission and connections during the early stage of hippocampal postnatal development, which promotes the development and functional maturation of hippocampus in rats.
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@#Objective To observe the influence of spinal cord injury on lower limbs weight support capacity,and the changes with time. Methods Six adult female rhesus monkeys with thoracic(T7-9)right spinal cord hemi-section were measured the plantar pressure ratio of both lower limbs with Foot-Scan system before,and six and twelve weeks after operation. Results There was no statistical difference between both sides of limbs before operation(Z=-1.330,P>0.05),while the plantar pressure ratio was more on the left limbs six and twelve weeks after operation(Z>4.783,P<0.001).The plantar pressure ratio of right lower limb became less and less during observation(Z=3.191,P<0.001). Conclusion The weight support capacity of affected limbs is injured after spinal cord hemi-section in monkeys, and would become worse without intervention.
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@#Objective To establish a three- dimensional hindlimb gait data toolkit (THGT) for healthy and spinal cord injured (SCI) non-human primate (rhesus monkey) based on Matlab to realize upload of original data, automatic gait division, calculation and drawing of multiple gait parameters, etc. Methods Vicon system was used to collect three-dimensional hindlimb gait data of healthy and SCI (after 6 weeks) rhesus monkey to obtain the kinematics data of both hindlimbs in continuous strides. It was analyzed with THGT to process the gait division, calculation and drawing of multiple gait parameters. Results THGT read the data, distinguished cycles of gait, calculated 140 kinds of gait parameters and drew graphs of the results. Conclusion THGT extends the universality of the Vicon data, realizes automatically gait division and friendly interactive interface, and puts out the visible results.
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<p><b>OBJECTIVE</b>To study the effect of vinorelbine on apoptosis, telomerase activity and expression of hTERT gene in human lung adenocarcinoma cell line Anip973 cells.</p><p><b>METHODS</b>Anip973 cells were cocultured with Vinorelbine at different concentrations and collected at 24 h, 48 h and 72 h after treatment, respectively. The inhibition rate of cell growth was determined by methyl thiazolyl tetrazolium (MTT) assay to evaluate the effect of vinorelbine. The percentage of apoptosis was detected by flow cytometry. The cellular morphology was observed under inverted microscope and electron microscope. Telomerase activity of Anip973 cells was determined by the method of TRAP-PAGE-silver staining. RT-PCR was used to detect the expression of hTERT mRNA.</p><p><b>RESULTS</b>Vinorelbine down-regulated the telomerase activity and expression of hTERT gene mRNA, inhibited the growth of Anip973 cells, and induced cell apoptosis in a time- and concentration-dependent manner. Annexin V-FITC assay showed 0.08 µg/ml NVB group could inhibited cell proliferation in 24 hour, and apoptosis rate was (7.37 ± 0.35)%, RT-PCR detection of hTERT mRNA expression in this group was (57.01 ± 1.71), and they were very significantly different from that in the control group (P < 0.01), but telomerase activity was (6.36 ± 0.06), compared with the control group showed no significant difference(P > 0.05). The change of hTERT mRNA expression is more sensitive than telomerase activity. The apoptosis rate, telomerase activity and hTERT mRNA expression of 0.4 µg/ml group and 2.0 µg/ml group were very significantly different from that in the control group (P < 0.01). The telomerase activity of 2.0 µg/ml at 72 hour group was (1.36 ± 0.27), basically completely inhibited, while the apoptosis rate was (74.87 ± 1.88)%, showed the cell apoptosis rate was in a negative correlation with the down-regulation of the hTERT mRNA (r = -0.96046, P < 0.01).</p><p><b>CONCLUSIONS</b>Vinorelbine can induce apoptosis in Anip973 cells, and its mechanism of action is related to telomerase activity. The detection of telomerase activity and expression of hTERT gene is useful in predicting prognosis of patients with lung adenocarcinoma.</p>