Functional Diversity of Mouse dLGN Neurons and Modulation of Their Encoding Properties by Superior Colliculus.

Abstract

Background: The dorsal lateral geniculate nucleus (dLGN) exhibits remarkable functional diversity, yet a systematic classification of its neuronal properties and the subcortical mechanisms that modulate these representations remains to be fully elucidated.

Methods: In this study, we performed a comprehensive functional mapping of the mouse dLGN using a diverse battery of visual stimuli. Neurons were grouped into clusters using unsupervised clustering of multi-dimensional response features, and the superior colliculus (SC) was pharmacologically silenced to assess its modulatory role.

Results: We identified at least 33 distinct functional clusters characterized by specialized tuning for contrast, frequency, and speed, as well as direction and orientation selectivity, providing a high-dimensional atlas of dLGN diversity. SC suppression triggered a multidimensional reorganization of dLGN properties that was cluster-specific and selectively affected various functional indices, including contrast sensitivity and feature selectivity, depending on the cell group.

Conclusions: These results indicate that distinct functional clusters of dLGN neurons exhibit heterogeneous modulation by SC inputs, demonstrating that collicular inputs are essential for shaping the diverse functional profiles of thalamic visual channels.