Different Regions Of Nervous System Research Articles

Epidermal growth factor regulates apoptosis and oxidative stress in a rat model of spinal cord injury

Spinal cord injury (SCI) leads to vascular damage and disruption of blood-spinal cord barrier which participates in secondary nerve injury. Epidermal growth factor (EGF) is an endogenous protein which regulates cell proliferation, growth and differention. Previous studies reported that EGF exerts neuroprotective effect in spinal cord after SCI. However, the molecular mechanisms underlying EGF-mediated protection in different regions of nervous system have not shown yet. In this study, we aimed to examine possible anti-apoptotic and protective roles of EGF not only in spinal cord but also in brain following SCI.Twenty-eight adult rats were divided into four groups of seven animals each as follows: sham, trauma (SCI), SCI + EGF and SCI + methylprednisolone (MP) groups. The functional neurological deficits due to the SCI were assessed by behavioral analysis using the Basso, Beattie and Bresnahan (BBB) open-field locomotor test. The alterations in pro-/anti-apoptotic protein levels and antioxidant enzyme activities were measured in spinal cord and frontal cortex.In our study, EGF promoted locomotor recovery and motor neuron survival of SCI rats. EGF treatment significantly decreased Bax and increased Bcl-2 protein expressions both in spinal cord and brain when compared to SCI group. Moreover, antioxidant enzyme activities including catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx) were increased following EGF treatment similar to MP treatment. Our experiment also suggests that alteration of the ratio of Bcl-2 to Bax may result from decreased apoptosis following EGF treatment. As a conclusion, these results show, for the first time, that administration of EGF exerts its protection via regulating apoptotic and oxidative pathways in response to spinal cord injury in different regions of central nervous system.

The Anesthetic Cascade

The Anesthetic Cascade

Cell-Intrinsic Differences between Stem Cells from Different Regions of the Peripheral Nervous System Regulate the Generation of Neural Diversity

Stem cells in different regions of the nervous system give rise to different types of mature cells. This diversity is assumed to arise in response to local environmental differences, but the contribution of cell-intrinsic differences between stem cells has been unclear. At embryonic day (E)14, neural crest stem cells (NCSCs) undergo primarily neurogenesis in the gut but gliogenesis in nerves. Yet gliogenic and neurogenic factors are expressed in both locations. NCSCs isolated by flow-cytometry from E14 sciatic nerve and gut exhibited heritable, cell-intrinsic differences in their responsiveness to lineage determination factors. Gut NCSCs were more responsive to neurogenic factors, while sciatic nerve NCSCs were more responsive to gliogenic factors. Upon transplantation of uncultured NCSCs into developing peripheral nerves in vivo, sciatic nerve NCSCs gave rise only to glia, while gut NCSCs gave rise primarily to neurons. Thus, cell fate in the nerve was stem cell determined.