The formation of single axon and multiple dendrites in a neural cell through distribution of specific functions to discrete cellular domains.
The neurons undergo complex morphological rearrangements to assemble into neuronal circuits and propagate signals. Hence they start as a round neuronal spheres and gradually adopting a complex morphology by forming one long axon and several shorted dendrites to eventually connect to target cell or other neurons via synapses. The central importance for the axon formation and the neuronal polarity is the specialized, highly motile cellular compartment at the tips of the growing axons called growth cone.
Different stages of neuronal polarity
Stage 1: Neuronal development starts with round spheres that spread a lamellipodium around the cell body
Stage 2: Then transform into cells containing several neuritis, which are decorated with dynamic growth cones at their tips.
Stage 3: Neurites at this early developmental stage show characteristic alternations of growth and retraction. The major polarity event is when one of these equally long neurites starts to grow rapidly to become the axon.
Stage 4: The next step is the morphological development of the remaining short neurites into dendrites.
Stage 5-6: Here Functional polarization of axons and dendrites, including synapse formation happens and dendritic spines are formed at later stages.
0 comments:
Post a Comment