Purchase this article with an account.
Ryuji Hisamura, Shigeru Nakamura, Imada Toshihiro, Yusuke Izuta, Kazuo Tsubota; Parasympathetic post-ganglionic nerves to the mouse exorbital lacrimal gland plays a role in tear secretion. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):338.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The Lacrimal Gland (LG) is innervated by parasympathetic, sympathetic and sensory nerve (Prog. Retin. Eye Res., 28(3):155, 2009). Blockade of parasympathetic pathway by the cleavage of pre-ganglionic nerve or surgical removal of the ganglion induced the decreased tear secretion. But these ganglionic nerves project to the nasal and the palatine mucosa and the cerebral vasculature other than the LG. In this study, we investigated the effect of surgical denervation of the post-ganglionic nerves projected to the LG on tear secretion.
The post-ganglionic nerves projected to the LG were denervated surgically in the female 8-week-old C57/B6J mouse. Because these post-ganglionic nerves include the sympathetic nerve from the superior cervical ganglion (SCG), surgical removal of the SCG experiment was performed to investigate whether sympathetic pathway participate in tear secretion. Moreover carbachol (CCh) continuous stimulation using osmotic pump was performed after post-ganglionic denervation to assess whether the lacrimal function was maintained by the stimulation of acetylcholine receptors in the LG. Tear secretion was evaluated by the cotton thread test.
There was a significant decrease in tear secretion in the post-ganglionic denervated group compared to the initial group (3.00±0.61mm to 0.50±0.35mm, p< 0.001, n=5). However there was no change in tear secretion in SCG removed group compared to the initial group (3.70±0.55mm to 3.70±0.45mm). In addition decreased tear secretion was recovered by the CCh continuous stimulation in the postganglionic denervated mice (0.40±0.22mm to 2.20±0.57mm, p< 0.001, n=5).
These results indicate that the parasympathetic post-ganglionic nerve fibers projected to the LG play the main role in regulating aqueous tear secretion.
This PDF is available to Subscribers Only