We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Assessing the Role of Inhibition in Stabilizing Neocortical Networks Requires Large-Scale Perturbation of the Inhibitory Population.
- Authors
Sadeh, Sadra; Silver, R. Angus; Mrsic-Flogel, Thomas D.; Muir, Dylan Richard
- Abstract
Neurons within cortical microcircuits are interconnected with recurrent excitatory synaptic connections that are thought to amplify signals (Douglas and Martin, 2007), form selective subnetworks (Ko et ah, 2011), and aid feature discrimination. Strong inhibition (Haider et ah, 2013) counterbalances excitation, enabling sensory features to be sharpened and represented by sparse codes (Willmore et ah, 2011). This balance between excitation and inhibition makes it difficult to assess the strength, or gain, of recurrent excitatory connections within cortical networks, which is key to understanding their operational regime and the computations that they perform. Networks that combine an unstable high-gain excitatory population with stabilizing inhibitory feedback are known as inhibitionstabilized networks (ISNs) (Tsodyks et ah, 1997). Theoretical studies using reduced network models predict that ISNs produce paradoxical responses to perturbation, but experimental perturbations failed to find evidence for ISNs in cortex (Atallah et ah, 2012). Here, we reexamined this question by investigating how cortical network models consisting of many neurons behave after perturbations and found that results obtained from reduced network models fail to predict responses to perturbations in more realistic networks. Our models predict that a large proportion of the inhibitory network must be perturbed to reliably detect an ISN regime robustly in cortex. We propose that wide-field optogenetic suppression of inhibition under promoters targeting a large fraction of inhibitory neurons may provide a perturbation of sufficient strength to reveal the operating regime of cortex. Our results suggest that detailed computational models of optogenetic perturbations are necessary to interpret the results of experimental paradigms.
- Subjects
NEURONS; OPTOGENETICS; INHIBITORY postsynaptic potential; SPARSE matrices; REINFORCEMENT learning; GENE regulatory networks
- Publication
Journal of Neuroscience, 2017, Vol 37, Issue 49, p12050
- ISSN
0270-6474
- Publication type
Article
- DOI
10.1523/JNEUROSCI.0963-17.2017