Neurons can exhibit burst firing and this presynaptic process basically results in a flurry of action potentials being fired in a short time window.

I'm, however, wondering how these signals are further relayed once they synapse onto other neurons? Specifically, does each action potential in the burst volley generate another post-synaptic action potential, or is the bursting somehow averaged to then transmit either one or no action potential post-synaptically depending on long the burst train was?


Short answer
It depends.

It all depends on the neuronal circuit and neurotransmitter system under investigation. For example, raphe neurons release 5-HT in a burst-like fashion onto cortical dendrites. However, the postsynaptic effect is inhibitory, so no action potentials there (Gartside, 2000).

Intracortical recordings in the rat have shown that each action potential in a burst resulted in neurotransmitter (glutamate) release and subsequent excitatory postsynaptic currents (EPSCs) and potentials (EPSPs) (Williams & Stuart, 1999). So that would positively answer your question, at least in this specific neuronal circuit.

- Gartside, Neurosci (2000); 98(2): 295-300
- Williams & Stuart, J Physiol (1999); 521(2): 467–82

  • $\begingroup$ Thanks @AliceD ! Are you aware of a case where presynaptic bursts lead to a single postsynaptic potential? I suppose excitatory relay neurons will most likely fire in bursts as well whereas the end target might integrate the incoming burst and only fire if there were "enough of them". Anyways, this was probably too loaded a question... $\endgroup$ – Moppentapper Mar 24 '18 at 1:03
  • $\begingroup$ @AliceD: Does "each action potential in a burst resulted in neurotransmitter release" literally mean, that each single action potential in a burst resulted in a single vesicle fusion - with probability 1? $\endgroup$ – Hans-Peter Stricker Jan 13 '20 at 15:22

This is just my personal opinion and impression:

First, it's not at all clear which effects burst firing of action potentials of a pre-synaptic neuron do have at the synaptic end bulbs: Does it cause a burst of fusions of vesicles and thus a burst of releases of neurotransmitters? Or isn't the intricate firing pattern completely smeared and blurred at the synapse?

Second: Each neuron's synaptic input to another neuron takes a long way (along the dendrite and so on) to get part of the effect at the axon hillock where post-synaptic action potentials are created. The firing pattern of the pre-synaptic neuron (which is one of thousands) will hardly be visible and mirrored here.

  • $\begingroup$ To the down-voter: What's so wrong with this answer? $\endgroup$ – Hans-Peter Stricker Jan 13 '20 at 15:04
  • 1
    $\begingroup$ Not the down-voter, but the referenced part is a question (answers are basically reserved for answers) and the answer part is unreferenced. $\endgroup$ – AliceD Jan 13 '20 at 18:56

Your Answer

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

Not the answer you're looking for? Browse other questions tagged or ask your own question.