TY - JOUR
T1 - Quantitative and qualitative analysis of asynchronous neural activity
AU - Ullner, Ekkehard
AU - Politi, Antonio
AU - Torcini, Alessandro
N1 - ACKNOWLEDGMENTS
A.T. received financial support by the Excellence Initiative I-Site Paris Seine (Grant No. ANR-16-IDEX-008), by the Labex MME-DII (Grant No ANR-11-LBX-0023-01) (together with A.P. and E.U.), and by the ANR Project ERMUNDY (Grant No ANR-18-CE37-0014), all part of the French program Investissements d’Avenir.
PY - 2020/4
Y1 - 2020/4
N2 - The activity of a sparse network of leaky integrate-and-fire neurons is carefully revisited with reference to a regime of bona fide asynchronous dynamics. The study is preceded by a finite-size scaling analysis, carried out to identify a setup where collective synchronization is negligible. The comparison between quenched and annealed networks reveals the emergence of substantial differences when the coupling strength is increased, via a scenario somehow reminiscent of a phase transition. For sufficiently strong synaptic coupling, quenched networks exhibit a highly bursting neural activity, well reproduced by a self-consistent approach, based on the assumption that the input synaptic current is the superposition of independent renewal processes. The distribution of interspike intervals turns out to be relatively long-tailed; a crucial feature required for the self-sustainment of the bursting activity in a regime where neurons operate, on average, (much) below threshold. A semiquantitative analogy with Ornstein-Uhlenbeck processes helps validate this interpretation. Finally, an alternative explanation in terms of Poisson processes is offered under the additional assumption of mutual correlations among excitatory and inhibitory spikes.
AB - The activity of a sparse network of leaky integrate-and-fire neurons is carefully revisited with reference to a regime of bona fide asynchronous dynamics. The study is preceded by a finite-size scaling analysis, carried out to identify a setup where collective synchronization is negligible. The comparison between quenched and annealed networks reveals the emergence of substantial differences when the coupling strength is increased, via a scenario somehow reminiscent of a phase transition. For sufficiently strong synaptic coupling, quenched networks exhibit a highly bursting neural activity, well reproduced by a self-consistent approach, based on the assumption that the input synaptic current is the superposition of independent renewal processes. The distribution of interspike intervals turns out to be relatively long-tailed; a crucial feature required for the self-sustainment of the bursting activity in a regime where neurons operate, on average, (much) below threshold. A semiquantitative analogy with Ornstein-Uhlenbeck processes helps validate this interpretation. Finally, an alternative explanation in terms of Poisson processes is offered under the additional assumption of mutual correlations among excitatory and inhibitory spikes.
U2 - 10.1101/2019.12.19.882456
DO - 10.1101/2019.12.19.882456
M3 - Article
VL - 2
JO - Physical Review Research
JF - Physical Review Research
SN - 2643-1564
IS - 2
M1 - 023103
ER -