Synaptic transmission

• What is the process of synaptic transmission?

  1. AP arrives at pre-synaptic neurone, causing calcium ion channels to open and Ca2+ to enter the synaptic knob by facilitated diffusion
  2. The influx of calcium ions causes synaptic vesicles to fuse with the pre-synaptic membrane, releasing the NT into the synaptic cleft
  3. The NT diffuses across the synaptic cleft and binds to receptor sites on sodium ion protein channels in the membrane of the post synaptic neurone
  4. Sodium ion channels open allowing sodium to diffuse into the post synaptic neurone, creating an AP
• What happens during reuptake?

  The NT diffuses back across the synaptic cleft into the pre synaptic neurone and is stored in the vesicles for future use
• What is an excitatory neurotransmitter?

  Increase the positive charge of the post-synaptic neurone, making it more likely to fire (excitatory post synaptic potential, EPSP)
• What is an inhibitory neurotransmitter?

  Increase negative charge of a neurone making it less likely to fire. This makes an inhibitory post synaptic potential (IPSP)
• What is the ion that enters the pre-synaptic knob?

  Calcium
• By what process does calcium ions enter the pre-synaptic knob?

  Facilitated diffusion
• What ion causes the action potential in the post-synaptic knob?

  Sodium