Synaptic Transmission

• Synapse


  - actions potential has arrived at terminal button, needs to be transferred to another neurone or to tissue.

  - presynaptic neurone and post synaptic neurone - in between synapse.

  - end of axon - synaptic vessels.

  - vesicles contain chemical messengers.

  - action potential reaches the synaptic vesicles - release contents.

  - released transmitters diffuses across the gap between pre and postsynaptic cell, binds to specialised receptors that recognise it.
• Excitatory Neurotransmitter


  - noradrenaline are excitatory - cause excitation of post synaptic neurone by increasing its positive charge making more likely to fire.

  - electrical charge in the membrane of that cell resulting in excitatory post synaptic potential making more likely to fire.
• Inhibitory Neurotransmitter


  - neurotransmitter serotonin causes inhibition in receiving neurone.

  - neurone becomes more negatively charge and less likely to fire.

  - generally responsible for calming mind and body inducing sleep and filtering out unnecessary excitatory signals.

  neurotransmitter binds with a postsynaptic receptor resulting in an postsynaptic potential so less likely to fire.