synaptic transmission

• synaptic transmission is the process by which a nerve impulse passes across a synaptic cleft from one neuron (the presynaptic neuron) to another (the postsynaptic neuron)
• synaptic transmissions happens as follows:

  1. an action potential arrives at the synaptic ending of the presynaptic neuron.
  2. this causes the vesicles (containing neurotransmitters) to move to the membrane of the presynaptic neuron and release their contents into the synaptic space
  3. the neurotransmitter diffuses across the synaptic gap where it binds to specific receptors on the surface of the postsynaptic neuron
  4. when the impulse has been transferred, re-uptake will take place
  5. neurotransmitters can also be ‘turned off’ by enzymes that make them ineffective