Multimodal gradient mapping of rodent hippocampus.

Area of Science:

• Neuroscience
• Computational Neuroscience
• Genomics

Background:

• The hippocampus is crucial for self-perception and spatial orientation.
• Previous research indicates functional variation along the hippocampal axis, but with debated discontinuity.
• Understanding hippocampal organization and its drivers is key.

Purpose of the Study:

• To map hippocampal functional connectivity (FC) organization in mice using gradient analysis.
• To investigate the relationship between genomic anatomy and functional organization.
• To clarify the nature of functional transitions along the hippocampal axis.

Main Methods:

• Gradient analysis of resting-state fMRI data in mice.
• Analysis of mouse gene co-expression data.
• Comparison of functional and genomic organizational principles.

Main Results:

• Two primary FC gradients identified along the hippocampal axis.
• A sharp discontinuity separated dorsal (spatial navigation) and ventral (emotion) hippocampus.
• Gene co-expression showed a more discrete organization than FC.

Conclusions:

• Hippocampal functional organization features both sharp and gradual transitions.
• Genomic anatomy has a limited influence on hippocampal functional organization.
• Findings align with human hippocampal functional segregation.