PT  - JOURNAL ARTICLE
AU  - Cian O’Donnell
AU  - J. Tiago Gonçalves
AU  - Carlos Portera-Cailliau
AU  - Terrence J. Sejnowski
TI  - Beyond excitation/inhibition imbalance in multidimensional models of neural circuit changes in brain disorders
AID  - 10.1101/086363
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 086363
4099  - http://biorxiv.org/content/early/2017/09/08/086363.short
4100  - http://biorxiv.org/content/early/2017/09/08/086363.full
AB  - A leading theory holds that neurodevelopmental brain disorders arise from imbalances in excitatory and inhibitory (E/I) brain circuitry. However, it is unclear whether this onedimensional model is rich enough to capture the multiple neural circuit alterations underlying brain disorders. Here we combined computational simulations with analysis of in vivo 2-photon Ca2+ imaging data from somatosensory cortex of Fmr1 knock-out (KO) mice, a model of Fragile-X Syndrome, to test the E/I imbalance theory. We found that: 1) The E/I imbalance model cannot account for joint alterations in the observed neural firing rates and correlations; 2) Neural circuit function is vastly more sensitive to changes in some cellular components over others; 3) The direction of circuit alterations in Fmr1 KO mice changes across development. These findings suggest that the basic E/I imbalance model should be updated to higher-dimensional models that can better capture the multidimensional computational functions of neural circuits.