neurotransmitters

• excitatory neurotransmitters 


  • increase likelihood
  • positively charged
• inhibitory neurotransmitters 


  • decrease likelihood
  • negatively charged
• excitatory neurotransmitters 


  • increase the likelihood that an excitatory signal will be sent (acetylcholine and noradrenaline)
  • adrenaline is a hormone and neurotransmitter, resulting in post synaptic membrane becoming positively charged
  • positively charged means that it is easier for the membrane to reach the threshold for when a new action potential is sent
• inhibitory neurotransmitters 


  • decrease the likelihood that an inhibitory signal will be sent (serotonin and GABA)
  • serotonin results in post synaptic membrane becoming negatively charged
  • negatively charged means that it is harder for the membrane to reach the threshold for when a new action potential is sent
• summation 


  the sum of the effects of the inhibitory and excitatory neurotransmitters
• more excitatory - more likely the threshold will be met (so action potential is sent)
• more inhibitory - less likely theshold will be reached (so action potential is not sent)
• summation 


  the net effect of the sum of excitatory and inhibitory neurotransmitters