Figure 4.

Signaling of synchronized transitions in the activity of a population of presynaptic neurons. (A) Experimentally recorded EPSPs generated by a Poisson spike train undergoing transition (indicated by arrow) from 10 to 40 Hz. The average membrane potentials before and after the transition (indicated by dashed line) were equal to the third decimal point. (B1) Simulated postsynaptic current, generated by Poisson spike trains, of a population of 500 presynaptic neurons with synchronous transitions from 1 to 10 Hz and then to 40 Hz, together with the response of a pyramidal neuron when the simulated synaptic current was injected into the soma. A population signal emerged as the number of neurons in the presynaptic pool was increased. Parameters of the model are the same as in Fig. 3. (B2) The same as B1 but with lower value of U_SE and twice as large A_SE. (C) Average voltage response recorded from a postsynaptic neuron after stimulating the presynaptic neuron with the sequence of 200 different Poisson spike trains undergoing the same transitions as in B.