inhibitory post synaptic potentials (IPSPs)

• • IPSPs can reduce the effect of summation and even prevent an action potential in the post synaptic membrane
  • in many cases, this inhibitory effect is caused by the opening of chloride (-) or potassium (+) ion channels
• why does this cause an inhibitory effect ?

  • chloride ions are negative so when they enter cells they make them more negative on the inside so cells find it more difficult to reach threshold
  • potassium ions leave cell membrane making it more negative
  • both make it harder for threshold to be reached