Bidirectionally connected cores in a mouse connectome: Towards extracting the brain subnetworks essential for consciousness
Jun Kitazono, Yuma Aoki, Masafumi Oizumi
bioRxiv Preprint Server July 12, 2021 preprint DOI: 10.1101/2021.07.12.452022 via bioRxiv
Summary
A method for hierarchically decomposing a brain network into cores based on the strength of bidirectional connections helps identify regions likely essential for consciousness. Applied to a whole-brain mouse connectome, cores with strong bidirectional connections included the isocortex, thalamus, and claustrum—areas thought to support consciousness—and excluded the cerebellum, which is not considered relevant. Simpler methods that ignore bidirectionality failed to show this correspondence. The findings suggest that analyzing bidirectional connectivity offers a novel way to relate brain network structure to consciousness.
Study at a glance
| Characteristics | Observational study |
|---|---|
| Population | Mouse brain connectome |
| Key finding | Cores with strong bidirectional connections in the mouse connectome include regions presumably essential to consciousness (isocortex, thalamus, claustrum) and exclude the cerebellum, whereas methods ignoring bidirectionality do not show this correspondence. |
Abstract
Where in the brain consciousness resides remains unclear. It has been suggested that the subnetworks supporting consciousness should be bidirectionally (recurrently) connected because both feed-forward and feedback processing are necessary for conscious experience. Accordingly, evaluating which subnetworks are bidirectionally connected and the strength of these connections would likely aid the identification of regions essential to consciousness. Here, we propose a method for hierarchically decomposing a network into cores with different strengths of bidirectional connection, as a means of revealing the structure of the complex brain network. We applied the method to a whole-brain mouse connectome. We found that cores with strong bidirectional connections consisted of regions presumably essential to consciousness (e.g., the isocortical and thalamic regions, and claustrum) and did not include regions presumably irrelevant to consciousness (e.g., cerebellum). Contrarily, we could not find such correspondence between cores and consciousness when we applied other simple methods which ignored bidirectionality. These findings suggest that our method provides a novel insight into the relation between bidirectional brain network structures and consciousness.