Functional circuits in the visual cortex require the coordinated activity of excitatory and inhibitory neurons. Molecular genetic approaches in the mouse have led to the “local non-specific pooling principle” of inhibitory connectivity, in which inhibitory neurons are untuned for stimulus features due to the random pooling of local inputs. However, it remains unclear whether this principle generalizes to species with a columnar organization of feature selectivity such as carnivores, primates, and humans. Here we use virally mediated GABAergic-specific GCaMP6f expression to demonstrate that inhibitory neurons in ferret visual cortex respond robustly and selectively to oriented stimuli. We find that the tuning of inhibitory neurons is inconsistent with the local non-specific pooling of excitatory inputs and that inhibitory neurons exhibit orientation-specific noise correlations with local and distant excitatory neurons. These findings challenge the generality of the non-specific pooling principle for inhibitory neurons, suggesting different rules for functional excitatory-inhibitory interactions in non-murine species.
Bibliographical noteFunding Information:
The authors wish to thank the GENIE project for GCaMP6f, Dominique Ouimet for surgical assistance, David Whitney, Ben Scholl, and other members of the Fitzpatrick lab for helpful discussions. This work was supported by grants from the National Institutes of Health: EY011488 (D.F.), EY023408 (D.F.), MH071679 (G.F.), NS08297 (G.F.), NS074972 (G.F.), as well as support from the Simons Foundation (SFARI) (G.F.) and the Max Planck Florida Institute for Neuroscience (D.F.).
- Visual cortex
- excitatory neurons
- inhibitory neurons
- orientation selectivity