Joseph Emerson¹, Brock Carlson¹, Ryan Holland^2,3, Yifan Hu^2,3, Audrey Sederberg^4,5, Gordon Smith^2,3, Cheryl Olman^1,2; ¹Department of Psychology, University of Minnesota - Twin Cities, ²Department of Neuroscience, University of Minnesota - Twin Cities, ³Optical Imaging and Brain Sciences Medical Discovery Team, University of Minnesota - Twin Cities, ⁴School of Physics, Georgia Institute of Technology, ⁵School of Psychology, Georgia Institute of Technology

Surround suppression in primary visual cortex (V1) is a form of contextual modulation in which neurons are suppressed by the presence of stimuli outside their classical receptive fields. However, the effects of temporal context on center-surround interactions remains poorly understood. To probe how temporal context influences center-surround interactions, we used two-photon calcium imaging in anesthetized ferrets while presenting drifting grating stimuli in two paradigms: a heterogeneous condition in which the grating is stepped rapidly through eight directions over 5 seconds, and a homogeneous condition in which the grating drifted in one direction before reversing mid-trial during 3-second trials. Each paradigm was shown both in a 15° aperture and full-field configuration to measure classical and extra-classical receptive field contributions. To our surprise, we found that population responses revealed stronger and more consistent surround suppression under heterogeneous stimulation, whereas the homogeneous stimulus produced a broader distribution spanning suppression to facilitation. These results provide evidence that the temporal context of orientation heterogeneity strongly influences the degree of surround suppression in ferret V1. Ongoing work aims to explain the sensitivity of local recurrent interactions that facilitate surround suppression to temporally-dependent network states.

Acknowledgements: NIH R01 NS123482