-transparent.png){kind=logo}
OBJECTIVE To study the innervation of the presumably contractile, myofibroblast-like scleral spur cells in human and cynomolgus monkey eyes. METHODS Serial tangential sections of the scleral spur region of the eyes of 16 human donors and 6 cynomolgus monkeys were investigated with immunocytochemical methods. Antibodies against acetylcholinesterase, synaptophysin, alpha-smooth muscle actin, calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY), nitric oxide synthase (NOS), substance P (SP), tyrosine hydroxylase (TH), and vasoactive intestinal peptide (VIP) were used. In addition, sections were processed for glyoxylic acid-induced catecholamine fluorescence (CF) and for NADPH-diaphorase (NADPH-d). RESULTS In the eyes of both species, circumferentially oriented varicose axons were observed in the scleral spur region of all quadrants. Double labeling showed that most of these scleral spur axons were in close contact with the alpha-smooth muscle actin-positive, myofibroblast-like scleral spur cells. In human eyes, the axons showed like-immunoreactivity (LI) for SP, CGRP, NPY, VIP, and NOS. In addition, numerous scleral spur axons stained for NADPH-d. Most SP-LI scleral spur axons were double-labeled for CGRP-LI, and none for VIP-LI. All NPY-LI scleral spur axons were double labeled for VIP-LI but lacked immunoreactivity to TH. Some VIP-LI axons were not labeled for NPY-LI. Nerve fibers immunoreactive (IR) for TH or positively stained for CF were not observed in association with scleral spur cells. In contrast, in cynomolgus monkey eyes, circumferentially oriented TH-IR and CF-positive varicose axons were observed frequently in the scleral spur region. In addition, SP-LI, CGRP-LI, and NPY-LI/TH-IR axons were present in the chamber angle of monkey eyes, whereas VIP-LI, VIP-LI/NPY-LI, NOS-positive, or NADPH-d-positive nerve fibers were absent. In both species, positive staining for acetylcholinesterase was seen only in the ciliary muscle, not in the scleral spur region. CONCLUSIONS The close association of varicose axons with the myofibroblast-like scleral spur cells indicates that nervous signals modulate scleral spur cell tone. A sympathetic scleral spur cell innervation is present only in cynomolgus monkeys but seems to be absent in humans. Conversely, scleral spur axons of presumably parasympathetic origin (NOS-IR or NADPH-d-positive, VIP-LI, and VIP-LI/NPY-LI) are absent in the cynomolgus monkeys but present in humans. In both species, a cholinergic innervation of the scleral spur cells seems to be rare or absent.
E R Tamm, and
T A Koch, and
B Mayer, and
F H Stefani, and
E Lütjen-Drecoll
April 1992,
Experimental eye research,
E R Tamm, and
T A Koch, and
B Mayer, and
F H Stefani, and
E Lütjen-Drecoll
June 1994,
Journal of anatomy,
E R Tamm, and
T A Koch, and
B Mayer, and
F H Stefani, and
E Lütjen-Drecoll
January 1998,
European journal of cell biology,
E R Tamm, and
T A Koch, and
B Mayer, and
F H Stefani, and
E Lütjen-Drecoll
January 1989,
Japanese journal of ophthalmology,
E R Tamm, and
T A Koch, and
B Mayer, and
F H Stefani, and
E Lütjen-Drecoll
January 1974,
Acta ophthalmologica,
E R Tamm, and
T A Koch, and
B Mayer, and
F H Stefani, and
E Lütjen-Drecoll
February 2015,
Investigative ophthalmology & visual science,
E R Tamm, and
T A Koch, and
B Mayer, and
F H Stefani, and
E Lütjen-Drecoll
July 2000,
Investigative ophthalmology & visual science,
E R Tamm, and
T A Koch, and
B Mayer, and
F H Stefani, and
E Lütjen-Drecoll
July 2002,
Investigative ophthalmology & visual science,
E R Tamm, and
T A Koch, and
B Mayer, and
F H Stefani, and
E Lütjen-Drecoll
October 1977,
Investigative ophthalmology & visual science,
E R Tamm, and
T A Koch, and
B Mayer, and
F H Stefani, and
E Lütjen-Drecoll
January 2012,
PloS one,
