Approximate, not Perfect Synchrony Maximizes the Downstream Effectiveness of Excitatory Neuronal Ensembles.
Abstract: The most basic functional role commonly ascribed to synchrony
in the brain is that of amplifying excitatory neuronal signals. The reasoning is
straightforward: When positive charge is injected into a leaky target neuron over a
time window of positive duration, some of it will have time to leak back out before
an action potential... read moreis triggered in the target, and it will in that sense be wasted.
If the goal is to elicit a firing response in the target using as little charge as
possible, it seems best to deliver the charge all at once, i.e., in perfect
synchrony. In this article, we show that this reasoning is correct only if one
assumes that the input ceases when the target crosses the firing threshold, but
before it actually fires. If the input ceases later—for instance, in response to a
feedback signal triggered by the firing of the target—the "most economical" way of
delivering input (the way that requires the least total amount of input) is no longer
precisely synchronous, but merely approximately so. If the target is a heterogeneous
network, as it always is in the brain, then ceasing the input "when the target
crosses the firing threshold" is not an option, because there is no single moment
when the firing threshold is crossed. In this sense, precise synchrony is never
optimal in the brain.
Keywords: Function of synchrony, Leakiness, Coincidence detection.
Springer Open.read less
- Börgers, Christoph, Jie Li, and Nancy Kopell. "Approximate, not Perfect Synchrony Maximizes the Downstream Effectiveness of Excitatory Neuronal Ensembles." The Journal of Mathematical Neuroscience 4, no. 1 (12, 2014): 1-22.