We consider clustered small-world networks (SWNs) with two inhibitory (I) and excitatory (E) populations. This I-E neuronal network has adaptive dynamic I to E and E to I interpopulation synaptic strengths, governed by interpopulation spike-timing-dependent plasticity (STDP). In previous works without STDPs, fast sparsely synchronized rhythms  were found to appear in a range of noise intensity D . Here, by varying D, we investigate the effect of interpopulation STDPs on population states in the I- and the E-populations. Depending on values of D, long-term potentiation (LTP) and long-term depression (LTD) for population-averaged values of saturated interpopulation synaptic strengths are found to occur, and they make effects on the degree of population synchronization. In a broad region of intermediate D, the degree of good synchronization (with higher spiking measure) becomes decreased, while in a region of large D, the degree of bad synchronization (with lower spiking measure) gets increased. Consequently, in each I- or E-population, the synchronization degree becomes nearly the same in a wide range of D. This kind of "equalization effect" is found to occur via cooperative interplay between the average occupation and pacing degrees of  synchronized rhythms. Such equalization effect is much more enhanced in the presence of combined I to E and E to I STDPs when compared with the case of individual I to E or E to I STDP. We note that the equalization effect in interpopulation synaptic plasticity is  in contrast to the Matthew (bipolarization) effect in intrapopulation (I to I and E to E) synaptic plasticity where good (bad) synchronization gets better (worse). Moreover , emergences of LTP and LTD of interpopulation synaptic strengths are intensively investigated via a microscopic method based on the distributions of time delays between the pre- and the post-synaptic spike times.
We consider clustered small-world networks with both inhibitory (I) and excitatory (E) populations. This I-E neuronal network has adaptive dynamic I to E and E to I interpopulation synaptic strengths, governed by interpopulation spike-timing-dependent plasticity (STDP). In previous works without STDPs, fast sparsely synchronized rhythms , related to diverse cognitive functions, were found to appear in a range of noise intensity D for static synaptic strengths. By varying D, we investigate the effect of interpopulation STDPs on diverse population and individual properties of fast sparsely synchronized rhythms that emerge in both the I- and the E-populations. Depending on values of D, long-term potentiation (LTP) and long-term depression (LTD) for population-averaged values of saturated interpopulation synaptic strengths are found to occur, and they make effects on the degree of fast sparse synchronization. In a broad region of intermediate D, the degree of good synchronization (with higher spiking measure) becomes decreased, while in a region of large D, the degree of bad synchronization (with lower spiking measure) gets increased. Consequently, in each I- or E-population, the synchronization degree becomes nearly the same in a wide range of D. This kind of "equalization effect" is found to occur via cooperative interplay between the average occupation and pacing degrees of fast sparsely synchronized rhythms. We note that the equalization effect in interpopulation synaptic plasticity is distinctly in contrast to the Matthew (bipolarization) effect in intrapopulation (I to I and E to E) synaptic plasticity where good (bad) synchronization gets better (worse). Finally , emergences of LTP and LTD of interpopulation synaptic strengths are intensively investigated via a microscopic method based on the distributions of time delays between the pre- and the post-synaptic spike times.
R
(SWNs) with two
with both
A
, related to diverse cognitive functions,
R
. Here, by
for static synaptic strengths. By
R
population states in
diverse population and individual properties of fast sparsely synchronized rhythms that emerge in both
R
population
fast sparse
A
fast sparsely
D
Such equalization effect is much more enhanced in the presence of combined I to E and E to I STDPs when compared with the case of individual I to E or E to I STDP.
A
distinctly
R
Moreover
Finally