Real Time Multiplicative Memory Amplification Mediated by Whole-Cell Scaling of Synaptic Response in Key Neurons
Fig 9
Whole-cell amplification functions as an instantaneous amplifier.
A. At the peaks of the fluctuations the effect of the amplification was larger. The synaptic activity exhibited the same pattern before and after the amplification thus demonstrating the instantaneous effect of whole-cell balanced amplification. B. The probability of the excitatory synapses was increased according to a time course described by an alpha function (tau = 24 ms), with a multiplication factor of 5, resulting in voltage transients that were considerably larger than the ongoing voltage fluctuations with a half time around 90 ms. Despite a different synaptic activity pattern, and the relatively short duration of these transients the amplification induced by whole-cell balanced amplification was very evident. In both traces the sodium conductance was set to zero to eliminate the action potentials. C. Whole-cell balanced amplification induced robust event based amplification where in the large majority of the synchronized events (74%) the number of spikes increased. Simulation were performed at 30 different simulation sets at which both resting potential and synaptic strength were varied (see Materials and Methods) D. Due to the multiplicative nature of whole-cell amplification, the increase in the number of spikes was pronounced during the increased voltage transients while the increase in the number of spikes during the baseline was negligible.