Environment geometry alters subiculum boundary vector cell receptive fields in adulthood and early development

Area of Science:

• Neuroscience
• Spatial Navigation
• Cognitive Science

Background:

• Landmark information is crucial for navigation.
• Boundary Vector Cells (BVCs) encode location relative to environmental boundaries.
• Understanding BVC function is key to understanding spatial representation.

Purpose of the Study:

• Characterize subiculum BVC prevalence and spatial tuning in adult and developing rats.
• Investigate the relationship between BVC spatial firing and boundary geometry.
• Explore the developmental trajectory of BVCs and their relation to the entorhinal cortex.

Main Methods:

• Electrophysiological recordings in rats (adult and developing).
• Analysis of BVC firing patterns in response to different environmental geometries (squares, circles, inserted barriers).
• Comparison of BVC maturation in the subiculum and entorhinal cortex.

Main Results:

• BVC directional tuning aligns with walls in square environments but is uniformly distributed in circular ones.
• Environmental geometry significantly alters BVC receptive fields.
• Inserted barriers reveal both excitatory and inhibitory components in BVC receptive fields.
• Subiculum BVCs exhibit slower maturation compared to entorhinal cortex cells.
• Both subiculum and entorhinal BVCs show early sensitivity to boundary geometry.

Conclusions:

• Environmental geometry fundamentally shapes BVC receptive fields.
• Inhibitory inputs play a role in BVC field formation.
• The hippocampal representation of space, via BVCs, inherently incorporates boundary geometry from early development.