Preganglionic Parasympathetic Denervation Rabbit Model for Innervation Studies.

Area of Science:

• Ophthalmology
• Neuroscience
• Anatomy

Background:

• Tear secretion is crucial for ocular surface health.
• The main lacrimal gland (LG) is the primary source of basal and reflex tears.
• Parasympathetic innervation plays a key role in regulating lacrimal gland function.

Purpose of the Study:

• To investigate the role of parasympathetic nerves in lacrimal gland innervation and tear secretion.
• To evaluate the effects of parasympathetic denervation on lacrimation.
• To assess the potential of glial cell-derived neurotrophic factor (GDNF) in mitigating denervation-induced effects.

Main Methods:

• Retrograde dye tracing was used to map LG innervation in male rabbits.
• Pre-ganglionic parasympathetic denervation was performed.
• Glial cell-derived neurotrophic factor (GDNF) was administered post-surgery.

Main Results:

• Parasympathetic ganglia in the pterygopalatine ganglion were predominantly stained.
• Parasympathetic denervation led to decreased tear secretion and increased dry eye staining scores (fluorescein and rose bengal).
• These effects persisted for at least 3 months post-surgery, with minimal improvement from GDNF administration.

Conclusions:

• The main lacrimal gland is primarily innervated by parasympathetic nerves.
• Parasympathetic denervation causes significant and persistent dry eye.
• Glial cell-derived neurotrophic factor (GDNF) showed limited efficacy in restoring tear secretion after denervation.