PhD Scientific Days 2025

Poster Session III. - R: Neurosciences

Interplay between retinotopic and orientation maps in the visual cortex of a high-acuity species

Name of the presenter

Csikós Klaudia

Institute/workplace of the presenter

HUN REN Természettudományi Kutatóközpont

Authors

Klaudia Csikós¹, Abel Petik¹, Domonkos Horvath¹, Attila B. Dobos¹, Alan Urban², Daniel Hillier¹

1: Institute of Cognitive Neuroscience and Psychology, HUN-REN Research Centre for Natural Sciences, Budapest, Hungary
2: Neuro-Electronics Research Flanders (NERF), VIB, Department of Neuroscience KU Leuven, imec, Leuven, Belgium

Text of the abstract

The primary visual cortex in mammals with high visual acuity, such as primates or cats, exhibits a patterned spatial organization. In visual cortex, neuronal circuits encode multiple stimulus dimensions, such as spatial position, eye dominance, light-dark polarity, orientation, and spatial resolution. Among these, orientation preference has been extensively studied, as it is critical for detecting object edges and shapes, with neurons tuned to similar orientations forming iso-orientation domains that create smoothly varying patterns across the cortical surface. Despite significant advances in imaging techniques, the three-dimensional organization of these functional maps and their interactions remain poorly understood.
We employed functional ultrasound (fUS) imaging to explore the 3D organization of the primary visual cortex, focusing on the interplay between retinotopic and orientation maps. High-resolution fUS enabled the identification of functional maps at multiple scales: from the centimeter scale across multiple cytoarchitectonic areas, to the millimeter scale at the pinwheel level, and down to sub-millimeter resolution within iso-orientation domain structures. This approach is particularly suited for its unique combination of high spatial resolution and sensitivity to hemodynamic changes, allowing detailed mapping of cortical functional architecture.
Our results reveal that local iso-orientation domains are shaped by their embedding within the global retinotopy map. This interdependence between retinotopic and orientation representations underscores how large-scale organization constrains local structure, optimizing the balance between global continuity and fine-scale feature processing in the visual cortex.
These findings provide insights into the organizational principles of the primary visual cortex, emphasizing the role of global orientation biases in shaping local cortical representations. By leveraging fUS imaging, this study unifies large-scale cortical mapping with fine-scale domain analysis, providing a methodological framework to explore the interplay between cortical maps in encoding the complete visual field. Integrating these scales is essential for understanding the mechanisms underlying sensory processing in the visual cortex.