Structure and process in synaptic

• Synaptic transmittion 


  are chemical messengers that diffuse across the synapse and are detected by receptor sites on other neurons.
• Excitation and Inhibition 


  -not all neurotransmitters result in propagation of an action potential.

  -Likelihood of an action potential being created in post-synaptic neuron depends on the concentration of IPSP's and EPSP's.

  -When excitary neuron binds to a receptor it creates an EPSP and this increases likelihood of it creating action potential e.g. adrenaline.

  -When an inhibitory neurotransmitter binds to the receptor it creates an IPSP which decreases likelihood of creating action potential. e.g. serotonin.
• Summation 


  is the process carried out by the axon hillock on the post-synaptic membrane. It is the net sum of IPSP's and EPSP's generated at the membrane.

  In order to generate action potential the post-synaptic neuron and must meet voltage threshold.

  -More EPSP's raises voltage so more likely to propergate.

  -More IPSP's lowers voltage so less likely to propergate action potential.