Synapses

• Synaptic Transmission- once the action potential reaches the axon terminal it needs to be transferred to the next neuron or tissue.
• Synapse- the meeting point between a neuron and a neuron tissue.
• 1. Electrical impulse needs to be transferred to another neuron via the synaptic gap between the two neurons.
• 2. The end of the pre-synaptic neuron consists of synaptic vesicles that contain chemical messengers that assist in transmission of electrical impulse (neurotransmitters).
• 2. As the action potential reaches the end of the axon, it causes the vesicles to open up.
• 3. Once neurotransmitter released into the gap, it diffuses across & binds to the receptors of the post synaptic neuron (dendrites) and then gets activated.
• 4. In post-synaptic neuron, chemical messenger converted into an electrical charge (action potential and fires transmission in that neuron).
• 4. If the neurotransmitter is inhibitory, it makes an impulse less likely and an excitatory neurotransmitter makes it more likely.
• 5. A nerve cell can receive both excitatory post-synaptic potential & inhibitory post- synaptic potential. (Determined by adding up the excitatory and subtracting of inhibitory synaptic input- if gives a post-synaptic potential above a threshold for that neuron, then it will become active).
• 6. Reuptake of the neurotransmitter back into the vesicles occurs which stops the stimulation of the post-synaptic neuron & recycles the chemical for next usage.