Biology subjects

Foucher, C. G.

Publications and source records attributed to Foucher, C. G..

3 recordsLinked to original sources

bioRxiv2026

LightSuite: scalable atlas registration and cell detection across the central nervous system

Deciphering brain-wide circuits requires large animal cohorts, yet computational bottlenecks in atlas registration and whole-volume cell detection reduce precision, reproducibility, and sample yield. We present LightSuite, an open-source framework enabling scalable, multimodal registration and cellular mapping across the central nervous system (CNS). LightSuite combines damage-resilient 3D point-cloud initialization with user-steerable non-rigid registration, and GPU-accelerated local background normalization for rapid, illumination-invariant cell detection. Applying LightSuite to Fos-dependent activity labeling in mice, we extracted reproducible, layer-resolved profiles of active cell density, soma-size distributions and per-animal labeling-efficiency factors. LightSuite computationally untwists and registers cleared spinal cords to map myeloarchitecture, reconstructs serial wide-field histology to map surface GluA1 distributions, resolves optic fiber tracks, and aligns in vivo functional ultrasound hemodynamics into common atlas coordinates. LightSuite establishes an integrated, accessible platform for cohort-level structural, molecular, and functional CNS mapping.

neuroscience↗

bioRxiv2024

Emergence of neocortical function in heterotopic neurons

Brains come in various sizes and shapes, yet how neuronal position constrains the type of circuits that they can form remains largely unknown. The spatial layout of anatomical structures with corresponding functions varies widely across species (J-4). Also, during evolution, anatomical structures have duplicated and then diverged to generate new circuits and functions (5, 6). Thus, it is critical to understand how the position of neurons constrains their integration into circuits and, ultimately, their function. To address this question, we studied EmlJ knockout mice in which subsets of neocortical neurons form a new structure below the neocortex termed heterotopia (Ht). We examined how this new location affects the molecular identity, topography, input-output circuit connectivity, electrophysiology, and functional properties of these neurons. Our results reveal a striking conservation of the cellular features and circuit properties of Ht neurons, despite their abnormal location and misorientation. Supporting this observation, these neurons were able to functionally substitute for overlying neocortical neurons in a behaviorally relevant task when the latter were optogenetically silenced. Hence, specific neuronal identities and associated function can be reproduced in altered anatomical settings, revealing a remarkable level of self-organization and adaptability of neocortical circuits.

neuroscience↗

bioRxiv2023

Cortical circuits for goal-directed cross-modal transfer learning

Adapting goal-directed behaviors to changing sensory conditions is a fundamental aspect of intelligence. The brain uses abstract representations of the environment to generalize learned associations across sensory modalities. The circuit organization that mediates such cross-modal generalizations remains, however, unknown. Here, we demonstrate that mice can bidirectionally generalize sensorimotor task rules between touch and vision by using abstract representations of peri-personal space within the cortex. Using large-scale mapping in the dorsal cortex at single-cell resolution, we discovered multimodal neurons with congruent spatial representations within multiple associative areas of the dorsal and ventral streams. Optogenetic sensory substitution and systematic silencing of these associative areas revealed that a single area in the dorsal stream is necessary and sufficient for cross-modal generalization. Our results identify and comprehensively describe a cortical circuit organization that underlies an essential cognitive function, providing a structural and functional basis for abstract reasoning in the mammalian brain.

neuroscience↗