Integrated Mechanisms of Anticipation and Rate-of-Change Computations in Cortical Circuits
Figure 6
In a Network Scheme with Both SFA and STD, Basic Integration and Spiking Mechanisms in the Postsynaptic Membrane Allow the Postsynaptic Neuron to Encode the Temporal Derivative
(A) Current injected into presynaptic neurons (Iin, solid black line).
(B) Synaptic conductance opening in the postsynaptic neuron Gsyn(t).
(C) Membrane voltage modulations resulting from synaptic currents and synaptic conductance changes when postsynaptic spiking is inactivated.
(D) Sample spike trains (above) and trial-averaged firing rate (below) of the postsynaptic neuron subject to the presynaptic network activity. In all panels, the dashed black curves trace the mathematical derivative of the input, rescaled by the s.d. and recentered by the mean of the plotted signal to allow a direct comparison. The network is exactly as in Figure 4E, with enabled synaptic integration and spiking mechanisms in the postsynaptic neuron. The firing rate curve in (D) was obtained from 400 different simulations and by averaging together normalized bell-curve of s.d. 10 ms centered at the time of spike occurrence. Average postsynaptic firing rate was 64 Hz.