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Neurotransmitters And Its Effect On The Brain

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Neurotransmitters communicate by transmitting signals from a neuron to a target cell through a synapse. Before this communication can happen, the neurotransmitter must be synthesized and stored in vesicles so that when an action potential arrives, the cell is ready to fuss with the membrane of the neuron. When the synaptic vesicle is ready, the final triggering of vesicle fusion with the presynaptic terminal membrane occurs rapidly in response to the action potential invasion of the terminal. This step is highly dependent on calcium ions, which enter the terminal through voltage-gated calcium channels (Steinberg & Walton, 1978; Westenbrock, 1981). This action potential causing the opening of calcium channels for calcium ions to stream into the presynaptic cleft. The presence of calcium ions cause the synaptic vesicle to open and release neurotransmitters which fuses into the cleft. Miledi (1967) suggested that the idea that calcium entry into the terminal is a key step in the neurotransmitter release process formed the basis of what is known as the “calcium hypothesis.” Next, when an action potential does arrive at the terminal, the neurotransmitter is released from the terminal into the synaptic cleft. When the neurotransmitter arrives into the synaptic cleft, it must be recognized by its own receptors in the postsynaptic cell to create the binding action, causing ion channels to open, thus changing membrane potential and initiating another action potential. After the
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