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CNS Development - Anatomy & Physiology (view source)
Revision as of 16:21, 4 August 2011
, 16:21, 4 August 2011→Neural Differentiation
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==Neural Differentiation==
==Neural Development==
In the early embryo as shown in the images above, the neural tube is formed and represents the initial stages of the formation of the brain and spinal cord. As the embryo develops, the neural tube continues to develop in conjunction with the formation of the vertebrae of the spine.
In the early embryo as shown in the images above, the neural tube is formed and represents the initial stages of the formation of the brain and spinal cord. As the embryo develops, the neural tube continues to develop in conjunction with the formation of the vertebrae of the spine.
===Development of Vertebrae===
===Development of Vertebrae===
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Therefore in neonates CSF taps must be caudal to the conus medullaris to avoid damaging the spinal cord.
Therefore in neonates CSF taps must be caudal to the conus medullaris to avoid damaging the spinal cord.
==Neuronal Differentiation==
An important element to the development of the CNS is the development and regulation of orientation within the embryo, i.e. which part is cranial, caudal, lateral etc. Within the neural tube this is controlled via '''HOX''' (Homeobox) transcription factors which ensure there is an orientation between rostral and caudal. Two HOX genes are expressed resulting in boundaries within the tissue that is expressing that particular gene. One HOX gene is expressed rostrally and the other along the length of the spinal cord. This ensures only appropriate neural development takes place for the given location and orientation.
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Within the neural tube there are also controls on orientation that facilitate the development of both dorsal and ventral horns of the spinal cord. An indentation in the neural canal called the '''Sulcus limitans''' deliniates the dorsal and ventral columns such that two distinct development 'plates' are formed. The '''Alar Plate''' is dorsal and gives rise to sensory neurons whilst the '''Basal Plate''' is ventral and gives rise to motor neurons.