الفهرس 
ANATOMY AND HISTOLOGY OF THE HUMAN SPINALOnly 14 pages are availabe for public view
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Abstract
Stem cells play a critical and essential role in the human body not only by providing the starting material for organs and tissues but also for their continual maintenance, growth and renewal through life.
The present study was carried out to detect and localize NSCs positive cells in spinal cord of albino rat at different postnatal ages.
Seventy albino rats were used to carry out this study. They were divided equally into seven age groups varies from neonatal (one day age), early childhood(one week age), late childhood(one month age), adolescence(3 months age), early adulthood(6months age), late adulthood(one year age) and senility (tow years age).
All studied groups of albino rats were subjected to: anesthesia, dissection, histological staining with Hx & E stains and immunostaining using specific stem cell marker called nestin and sox2. Then, the slides were studied using light microscope. After that, morphometrical studies were done to evaluate the density of the neural stem cells using computer based image analysis system for measuring the numerical densities of immunostained positive cells.. Finally, data were subjected to statistical analysis.
In the present study, positive cells were detected in one day age then gradually decreased till the age of 6 months and became negative at one and two years. In addition, the densities of positive cells were higher in cervical region than both lumbosacral and thoracic region; the latter showed the lowest density at all studied age groups. The densities of positive cells were higher in white matter, followed by posterior horn, zone around the central canal and anterior horn in order.
In the current work, immunostained positive cells appeared rounded, oval, fusiform, bibolar or star-shaped; with large nucleus. These cells appeared scattered or in aggregations. The cytoplasm of nestin positive cells was stained brownish but that of sox2 positive cells was stained red.
from this study, it was concluded that spinal cord of rats contained neural stem cells that presented from early life (neonatal day one) up to six months then disappeared at old age. Further efforts should be devoted to delineate the differentiation mechanism of NSCs and their functional capacity in the repair and remodeling of injured spinal cord.
At the end of the present study, it is recommended to:
a- Design further research to examine the role of stem cells in spinal cord regeneration.
b- Design further studies to identify the role neural stem cells in differentiation to different types of neural cells and also detection of factors helping this differentiation.
c- These present results can suggest the use of endogenous neural stem cells in young age and exogenous neural stem cells in old age during management of spinal cord injuries.
d- Also, the behavior of neural stem cells during injury should be studied and clarified to know whether these cells migrate to the site of injury or not and if it migrate what are the factors helping this migration.