Kavli Affiliate: John Reynolds, Kenneth Miller
| Authors: Alessandro Sanzeni, Agostina Palmigiano, Tuan H Nguyen, Junxiang Luo, Jonathan J Nassi, John H Reynolds, Mark H Histed, Kenneth D Miller and Nicolas Brunel
| Summary:
The ability to observe the response of neural circuits to controlled optogenetic perturbations opens an unprecedented window into the mechanisms governing network dynamics and computations. We combined an analysis of neuronal responses to visual and optogenetic inputs in mice and monkey V1 with theoretical modelling. In both species, we found that optogenetic stimulation of excitatory neurons strongly modulated the activity of single neurons, but had only a weak effect on the distribution of firing rates across the population. Key statistics of responses of mice and monkeys lay on a continuum, with mice/monkeys occupying the low/high rate regions, respectively. At high contrast of the visual stimulus, optogenetic inputs did not significantly affect the distribution of firing rates, i.e. they reshuffled firing rates across the network. We show that neuronal reshuffling emerges generically in randomly connected networks of excitatory and inhibitory neurons, as long as the combination of recurrent coupling and feedforward input is sufficiently strong so that a powerful inhibitory feedback cancels the mean increase in firing rate due to optogenetic input.