PT  - JOURNAL ARTICLE
AU  - Yann Sweeney
AU  - Jeanette Hellgren Kotaleski
AU  - Matthias H. Hennig
TI  - A diffusive homeostatic signal maintains neural heterogeneity and responsiveness in cortical networks
AID  - 10.1101/011957
DP  - 2014 Jan 01
TA  - bioRxiv
PG  - 011957
4099  - http://biorxiv.org/content/early/2014/11/29/011957.short
4100  - http://biorxiv.org/content/early/2014/11/29/011957.full
AB  - Gaseous neurotransmitters such as nitric oxide (NO) provide a unique and often overlooked mechanism for neurons to communicate through diffusion within a network, independent of synaptic connectivity. NO provides homeostatic control of intrinsic excitability. Here we conduct a theoretical investigation of the distinguishing roles of NO-mediated diffusive homeostasis in comparison with canonical non-diffusive homeostasis in cortical networks. We find that both forms of homeostasis provide a robust mechanism for maintaining stable activity following perturbations. However, the resulting networks differ, with diffusive homeostasis maintaining substantial heterogeneity in activity levels of individual neurons, a feature disrupted in networks with non-diffusive homeostasis. This results in networks capable of representing input heterogeneity, and linearly responding over a broader range of inputs than those undergoing non-diffusive homeostasis. We further show that these properties are preserved when homeostatic and Hebbian plasticity are combined. These results suggest a mechanism for dynamically maintaining neural heterogeneity, and expose computational advantages of non-local homeostatic processes.