Whether or not an action potential is generated in a postsynaptic neuron depends on a number of factors. What are they? What ultimately determines whether or not an action potential is generated in the postsynaptic neuron?
Whether or not an action potential is generated in a postsynaptic neuron depends on a number of factors. What are they? What ultimately determines whether or not an action potential is generated in the postsynaptic neuron?
Related textbook solutions
Related questions
1. True or False: A postsynaptic potential isexcitatory (EPSP) if the ion involved has a reversal potential(Eion) that is more depolarized than the resting membrane potential(Vm or Vrest), even if that Eion is hyperpolarized to the thresholdfor firing an action potential.
2. An EPSP causes adepolarization of 15 mV on a proximal dendrite. At the same time,an IPSP causes a hyperpolarization of 10 mV in a different proximaldendrite.
Vm is -65 mV, and threshold for firing an action potential is-55 mV.
In this case, will an action potential be generated?
A. No, because the net effect on the membrane is -60 mV, whichis below threshold. | ||
B. Yes, because the EPSPs travel faster than IPSPs, so thehillock (trigger zone) will be stimulated to -50 mV, which exceedsthreshold. | ||
C. Maybe. We don't have enough information to answer this. | ||
D. It depends on factors like "how much will the gradedpotentials decay before they arrive at the hillock". In short, ifthe axon hillock (trigger zone) is depolarized beyond -55 mV, theanswer is "yes". If not, then "no". |
