Innervation of the mouse cornea during development

Area of Science:

• Ophthalmology
• Developmental Biology
• Neuroscience

Background:

• Corneal nerves are vital for maintaining eye homeostasis and transparency.
• Adult corneal innervation is well-documented, but developmental patterns remain largely unknown.
• Understanding corneal nerve development is key to addressing related pathologies.

Purpose of the Study:

• To provide a detailed profile of mammalian corneal innervation during development.
• To elucidate the spatiotemporal pattern of nerve projection into the developing mouse cornea.
• To characterize the formation of stromal and epithelial nerve networks.

Main Methods:

• Collection of mouse heads and corneas at various developmental stages (embryonic and postnatal).
• Immunostaining using neuron-specific β-tubulin antibody (TUJ1).
• Whole-mount and section imaging to analyze axonal projections and nerve branching patterns.

Main Results:

• Nerve bundles first appear at the eye periphery by embryonic day 12.5.
• Direct stromal innervation begins at embryonic day 13.5, bypassing a pericorneal nerve ring.
• Epithelial innervation starts at embryonic day 16.5, with nerves progressively organizing into a central swirl pattern by adulthood.

Conclusions:

• Mouse corneal innervation originates from four quadrants, directly accessing the stroma.
• The developing cornea lacks a pericorneal nerve ring during initial innervation.
• Epithelial nerve arrangement transitions from radial to a distinct central swirl pattern postnatally.