The word “dendrite” is derived from the Greek for “tree” and it’s no wonder why! The branches of a neuron do often have an uncanny resemblance to the branches of a tree! Lots of dendrite related phrases also relate back to the tree – “dendritic branching,” “dendritic arbor.”ĭendrites form synapses with the axons of other cells. If you were lucky you may have come across myelin sheath in our datasets, and have had the conundrum over whether to include it in your trace or not (we’ve collectively decided not to trace it for consistency). One final thing you may know about the axon is that it sometimes is blanketed in a myelin sheath, a fatty substance that protects the axon and increases the speed of signal transmission. Depending on the activated receptors, the target cell can be excited, inhibited, or have an altered metabolism.The neurotransmitter binds to receptors activated by the neurotransmitter chemical.The neurotransmitter is released from the presynaptic neuron.The increasing calcium concentration signals synaptic vesicles to fuse with the axon’s membrane and empty neurotransmitter chemicals.Calcium ion channels in the axon’s membrane open. The synaptic process follows these steps (often in less than a 1000th of a second!): There is an exception to this rule however – some types of neurons with short axons carry graded electrochemical signals with variable amplitude. Action potentials are “all-or-nothing” signals, meaning they travel from one end of the axon to the other without any reduction in size. Most axons carry action potentials – electrochemical impulses that begin at the cell body and travel along the axon, terminating at points where the axon makes a synaptic connection with its target cell.
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