This picture was taken from Purves' Neuroscience, chapter 5:

enter image description here

Image (C) shows a inhibitory postsynaptic potential whose reversal potential "goes" to the action potential. If two or more IPSPs occur, will temporal summation cause an action potential?

  • $\begingroup$ What do you think, based on the other information in C? $\endgroup$ – Bryan Krause Nov 15 '19 at 15:27
  • $\begingroup$ @BryanKrause I would say yes, but this seems to contradict the "inhibitory". Also, why is this "homework"? $\endgroup$ – Gabriel Nov 17 '19 at 0:51
  • $\begingroup$ This is exactly how I would write a homework or exam question for a basic neuroscience course. We don't allow answers to those sorts of questions, because the whole point is to work through it yourself. There are 2 other lines besides the IPSP voltage trace drawn in panel C. What do they mean? Also, have you looked at panel D? What is it telling you? $\endgroup$ – Bryan Krause Nov 17 '19 at 3:44
  • $\begingroup$ @BryanKrause Well, it isn't homework... It's a question I come up when reading Purves. I see that Panel D say say if the reversal potential is below the threshold the postsynaptic potential, and according to Purves, this is inhibitory because the change in V will be "pushed" toward the reversal potential of the specific synapse (GABA in this case). But if many inhibitory occur by definition, why can't the temporal summation of IPSPs be enough to reach the threshold value to fire the AP? this sum I'm thinking of can occur by different receptors. $\endgroup$ – Gabriel Nov 17 '19 at 13:16
  • $\begingroup$ What is the meaning of the reversal potential for a given ion or type of channel? $\endgroup$ – Bryan Krause Nov 17 '19 at 15:41

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.