Modular microcircuit organization of the presubicular head-direction map

Area of Science:

• Neuroscience
• Systems Neuroscience
• Computational Neuroscience

Background:

• The internal sense of direction relies on head-direction (HD) neurons.
• The dorsal presubiculum (PreS) is a key brain region for cortical HD representation.

Purpose of the Study:

• To investigate the microcircuit organization of the mouse dorsal presubiculum (PreS).
• To understand how this organization supports head-direction (HD) neural representations.

Main Methods:

• Analysis of the modular "patch-matrix" organization in the mouse dorsal presubiculum.
• Identification of calbindin-positive layer 2 neurons and their microcircuits.
• Tracing inputs from thalamic nuclei (anterodorsal and laterodorsal).
• Optogenetic perturbation of microcircuits in identified HD cells.

Main Results:

• The dorsal presubiculum exhibits a conserved "patch-matrix" organization across species.
• Modular recurrent microcircuits are formed by calbindin-positive neurons in the "matrix" layer.
• Thalamic inputs selectively target "patch" and "matrix" compartments.
• HD cells sample inputs non-randomly within the "matrix" layer.
• Perturbing microcircuits tonically suppresses firing in a subpopulation of HD neurons.

Conclusions:

• The dorsal presubiculum possesses a modular microcircuit organization underlying the HD map.
• Cell-type-specific microcircuits within the PreS are essential for cortical HD representation.
• This modular architecture supports precise structure-function relationships in spatial navigation.