Synaptic transmission

• Synaptic Transmission

  1. Electrical impulse reaches axon terminals
  2. Molecules of neurotransmitters are released across the synaptic gap
  3. Attach to postsynaptic receptors
  4. Triggers an electrical impulse
  5. Electrical impulse triggers synaptic vesicles to release neurotransmitters
  6. neurotransmitters diffuse across the synaptic gap
  7. bind to specialised receptor sites
• Impulses can either be excitatory or inhibitory.

  Excitatory - makes a nerve impulse more likely to be triggered. Excitatory postsynaptic potential (EPSP)

  Inhibitory - makes a nerve impulse less likely to be triggered. Inhibitory postsynaptic potential (ISPS)
• SUMMITATION

  • the excitatory or inhibitory influences on the post synaptic neuron are summed
  • if the net effect on the post synaptic is inhibitory, the neuron will be less likely to 'fire',
  • if its excitatory, the neuron will be more likely to fire
• Neurotransmitters are chemical messengers that transmit signals across the synaptic gap between neurons. When an electrical impulse reaches the end of a neuron (the presynaptic terminal), it triggers the release of neurotransmitters into the synapse. These chemicals bind to receptors on the postsynaptic neuron. Excitatory neurotransmitters increase the likelihood that the postsynaptic neuron will fire, while inhibitory neurotransmitters decrease this likelihood.