Can dendrites become myelinated

22.6 Basics of brain development

In the course of their development, the axons of the neuroblasts expand over considerable distances. Often they follow winding paths in order to connect to theirs Target organs outside the CNS to ensure (muscles, glands, receptors or synaptic connections with other neurons). The active path search starts from the growth cone. This free end represents a temporary, mobile structure whose job it is to explore the extracellular environment. It also speaks of various soluble and membrane-bound Signal molecules at. The latter seem to be influenced by the growth cone Growth rate and Direction of propagation to show the way. The surface of the growth cone consists of flattened membrane leaves, the Lamellipods, of which fine points of cell adhesion Filopodia go out. These processes contain actin filaments and myosin filaments that contract rhythmically (video: 2.1 Mb.). As soon as the growth cone has reached the target organ, it experiences changes in the cytoskeleton, its growth comes to a standstill, it flattens out and forms the Synapse. It should be noted that the somatic sensory and motor neurons come into direct synaptic contact with their target organ, while the vegetative nerve cells release their neurotransmitters from a certain distance to the target (synapses à distance, synapses en passant).