Contextual modulation emerges by integrating feedforward and feedback processing in mouse visual cortex

• Published in: Cell reports (Cambridge) Vol. 44; no. 1; p. 115088
• Main Authors: Di Santo, Serena, Dipoppa, Mario, Keller, Andreas, Roth, Morgane, Scanziani, Massimo, Miller, Kenneth D.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 28.01.2025; Elsevier
• Subjects: Animals; contextual modulation; cortical microcircuitry; CP: Neuroscience; feedback; Feedback, Physiological; higher visual areas; inhibitory subclasses; Mice; Models, Neurological; Neurons - physiology; perception; surround facilitation; surround suppression; visual cortex; Visual Cortex - physiology; feedback; inhibitory subclasses; visual cortex; surround facilitation; CP: Neuroscience; contextual modulation; higher visual areas; cortical microcircuitry; surround suppression; perception
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2024.115088

Sensory systems use context to infer meaning. Accordingly, context profoundly influences neural responses to sensory stimuli. However, a cohesive understanding of the circuit mechanisms governing contextual effects across different stimulus conditions is still lacking. Here we present a unified circuit model of mouse visual cortex that accounts for the main standard forms of contextual modulation. This data-driven and biologically realistic circuit, including three primary inhibitory cell types, sheds light on how bottom-up, top-down, and recurrent inputs are integrated across retinotopic space to generate contextual effects in layer 2/3. We establish causal relationships between neural responses, geometrical features of the inputs, and the connectivity patterns. The model not only reveals how a single canonical cortical circuit differently modulates sensory response depending on context but also generates multiple testable predictions, offering insights that apply to broader neural circuitry. [Display omitted] •One “toy” model explains three different types of contextual modulation•The widths of spatial response patterns grow much more slowly than stimulus size•Inverse responses depend on the geometry of feedback response fields and projections•Summation of classical and inverse response accounts for surround facilitation Our brain’s sensory systems use context to make sense of what we see, but the exact mechanisms behind this are not well understood. Di Santo et al. developed a unifying (toy) model of the mouse visual cortex that shows how brain cells work together to blend sensory input with contextual information.