IOVS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

(Investigative Ophthalmology and Visual Science. 2004;45:361-367.)
© 2004 by The Association for Research in Vision and Ophthalmology, Inc.
DOI:  10.1167/iovs.03-0624
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via ISI Web of Science (12)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by May, C. A.
Right arrow Articles by Lütjen-Drecoll, E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by May, C. A.
Right arrow Articles by Lütjen-Drecoll, E.

Immunohistochemical Classification and Functional Morphology of Human Choroidal Ganglion Cells

Christian Albrecht May,1 Winfried Neuhuber,2 and Elke Lütjen-Drecoll1

1From the Departments of Anatomy II, and 2Anatomy I, Friedrich-Alexander University, Erlangen, Germany.


   Abstract
Top
 Abstract
Material and Methods
 Results
 Discussion
 References
 
PURPOSE. To characterize human choroidal ganglion cells (CGCs) further, regarding their immunohistochemical and ultrastructural appearance and their pre- and postsynaptic connections.

METHODS. Choroidal wholemounts and serial sections of human donor eyes were stained with antibodies against neuronal nitric oxide synthase (nNOS), vasoactive intestinal peptide (VIP), tyrosine hydroxylase (TH), vesicular monoaminergic transporter (VMAT)-2, vesicular acetylcholine transporter (VAChT), neuropeptide Y (NPY), substance P (SP), calcitonin gene-related peptide (CGRP), calretinin, galanin, synaptophysin, and {alpha}-smooth muscle actin. Ultrathin sections of glutaraldehyde-fixed eyes were studied with an electron microscope.

RESULTS. All CGCs stained for nNOS, most for VIP, approximately 45% for calretinin, and only single neurons for NPY and galanin. Ultrastructurally, the CGCs showed an incomplete glial sheath and, in places, showed close contact to surrounding collagen fibrils. The CGCs were in close contact with numerous boutons staining for the different neuronal markers including synaptophysin, nNOS, VIP, NPY, TH, VMAT-2, VAChT, calretinin, and NPY.

CONCLUSIONS. The data indicate a complex integrative function of CGCs. The immunohistochemical and ultrastructural characteristics also indicate that the CGCs may have mechanosensory properties. The complex synaptic information points to a specific regulative CGC function in parallel with ciliary muscle contraction (accommodation). Axons originating from CGCs mainly supply the choroidal vasculature, thus implicating the CGCs as vasodilative neurons, but single CGCs may also innervate other structures such as nonvascular choroidal smooth muscle cells.

It is well established that the uvea in most species is innervated by two parasympathetic pathways, namely by nerves deriving from the ciliary ganglion and by those deriving from the sphenopalatine ganglion.

Within the uvea of human eyes, an additional group of nitric oxide synthase (NOS) and vasoactive intestinal peptide (VIP)-immunoreactive (IR) neurons has recently been discovered.1 2 3 Approximately, 2000 of these neurons are located in the inner portion of the ciliary muscle and presumably are involved in fine regulation of the accommodation.3 In addition, approximately 2000 neurons are present in the choroid. Most of the postganglionic nerve fibers of these choroidal ganglion cells (CGCs) join the perivascular nerve fiber plexus that supports the vasodilative innervation of the choroidal vasculature.1 2 A small number of these CGCs is located within the ciliary nerves. The postganglionic nerve fibers of this group of neurons do not enter the choroid but join the nerve fiber plexus that innervates the outflow system.4

When different mammalian eyes were compared, substantial numbers of CGCs in the posterior choroid were found only in higher primates and human eyes containing a fovea centralis.5 CGCs are also present in a number of birds with a specialized accommodative system and one or more foveae.6 7 Further characterization of the CGCs in the duck revealed that in addition to NO and VIP, the CGCs express galanin. The postganglionic fibers of these cells innervate not only the choroidal vasculature, but also the numerous non–vascular smooth muscle cells (NVSMCs) present in the avian choroidal stroma.8 Duck CGCs are surrounded by tyrosine hydroxylase (TH)/dopamine-ß-hydrolase (DBH)–immunoreactive nerve fibers forming synaptic contacts with the CGCs.9 Evidence has shown that these fibers derive from the superior cervical ganglion. The CGCs in the duck also receive calcitonin gene-related peptide (CGRP)–positive efferent collaterals of trigeminal afferents that may indicate precentral reflex arcs.10 Innervation of CGCs by postsynaptic sympathetic fibers in the avian eye, however, indicates a more complex integrative function of the ganglion cell plexus, similar to that in the enteric nervous system.9

It is not yet known whether CGCs in primate eyes have a similar complex function. In the present study we investigated human CGCs to clarify which neurotransmitters are expressed by these cells, to characterize their presynaptic input, and to define their target tissue.


   Material and Methods
Top
 Abstract
 Material and Methods
Results
 Discussion
 References
 
The studies were performed in 50 human eyes with no previous clinical history of ocular disease, the donors ranging in age between 12 and 95 years. The eyes were obtained during autopsy 4 to 36 hours after death. All donors had given permission to use their tissues for research. Tissue observation was in accordance with the Declaration of Helsinki and the local regulations. Eyes with obvious signs of ocular disease (e.g., macular degeneration, loss of retinal pigmented epithelium) or ocular treatment other than artificial lens implantation (e.g., laser-treatment of the retina) were excluded from the study. A further histologic screening for ocular disease was not performed.

Immunohistochemistry
Thirty-seven eyes of human donors ranging in age between 12 and 95 years were observed 11 to 36 hours after death. All eyes were incised equatorially and fixed either for 4 hours in neutral buffered 4% paraformaldehyde (PFA) or for 12 hours in Zamboni fixative, containing 4% PFA and 0.01% picric acid. The tissue was then rinsed in phosphate-buffered saline (PBS, pH 7.4) several times. In 27 eyes, the posterior segments were divided into four quadrants and wholemounts of the choroid and sclera were performed. From some of the wholemounts and from the remaining eyes, serial 14- to 16-µm-thick sagittal and tangential sections were cut through the choroid and sclera with a cryostat (Leica, Bensheim, Germany) and mounted on poly-L-lysine–coated glass slides.

Incubation with the primary antibody was performed overnight at room temperature, with the antibody diluted in PBS containing 1% bovine serum albumin and 0.1% Triton X. Control experiments were performed by incubating the sections only with the dilution solution. The primary antibodies used are listed in Table 1 . The sections and wholemounts were then rinsed in PBS and incubated for 1 hour with an appropriate fluorescent-dye–conjugated secondary antibody, diluted in PBS (Dianova, Hamburg, Germany). In the double-staining procedure, the steps were the same, but the incubation time of the primary antibody was reduced to 4 to 6 hours.


View this table:
[in this window]
[in a new window]
  		TABLE 1. Specification of the Primary Antibodies Used in the Study

 
Most of the antibodies showed sufficient staining in all specimens obtained, regardless of the donor age, time since death, or fixation. For some antibodies, certain special conditions must exist in the tissue to promote sufficient staining. Therefore, the number of tissue specimens was limited for these markers. The antibody against VIP showed sufficient staining of CGCs only in tissue fixed for 24 hours in Zamboni fixative and with a time since death of less than 24 hours. PFA-fixed specimens showed axonal VIP staining but no staining of the CGCs. Staining with the antibody against neuropeptide Y (NPY) was only possible by using cryosections of both PFA- and Zamboni-fixed specimens. Wholemounts did not show sufficient staining of either neurons or nerve fibers.

All sections were mounted with Kaiser glycerol jelly and viewed with a fluorescence microscope (Aristoplan; Leica) or with a confocal laser scanning system (MRC 1000; Bio-Rad, Munich, Germany) attached to an inverted microscope (Diaphot 300; Nikon, Tokyo, Japan). In estimating the size of single neurons, a diameter was defined as the shortest distance between opposing cell boundaries, when passing through the center of the cell.

Electron Microscopy
The ultrastructural morphology and the surrounding tissue of the CGCs was investigated in 13 eyes of donors ranging in age between 56 and 91 years. The eyes were obtained 4 to 24 hours after death, incised equatorially, and fixed in 4% PFA and 1% glutaraldehyde for at least 24 hours.

Small samples of the choroid and sclera were prepared and embedded in Epon. Sagittal and tangential semithin serial sections (1 µm thick) were performed and stained with toluidine blue. From localized CGCs, ultrathin sections were performed, stained with leaded citrate and uranyl acetate, and viewed with a transmission electron microscope (model EM 902; Carl Zeiss Meditec, Oberkochen, Germany).


   Results
Top
 Abstract
 Material and Methods
 Results
Discussion
 References
 
Choroidal Ganglion Cells
In human choroidal sections and wholemounts incubated with antibodies against neuronal NOS (nNOS), all 1820 visualized CGCs showed positive staining (Fig. 1A) . No additional CGCs, either identified by their content of autofluorescent lipofuscin or by a nonspecific light fluorescent background in the neuronal cytoplasm, were detected in the nNOS-stained specimens. The nNOS staining was independent of the size (10–37 µm in diameter) and the location of the neurons. Numerous axons within the suprachoroidal nerve plexus and around choroidal vessels were also nNOS IR.



View larger version (120K):
[in this window]
[in a new window]
  		FIGURE 1. (A, B) Double-immunofluorescent staining of two human choroidal ganglion cells for nNOS (A) and VIP (B). (C) A human choroidal flatmount stained with antibodies against calretinin shows a positive neuronal network and some immunoreactive neurons. Original magnification: (A, B) x400; (C) x200.

 
Staining with antibodies against VIP revealed that most of the CGCs (354/362 CGCs evaluated) were VIP IR. Colocalization was documented by double staining with antibodies against nNOS and VIP (Fig. 1B) . It appeared that the few VIP-negative CGCs, visualized by autofluorescent lipofuscin or by a nonspecific light fluorescent background, were of smaller size (12–18 µm in diameter).

Less frequent IR in CGCs was seen in choroidal tissue stained with antibodies against calretinin. Wholemounts revealed that 82 of the 146 CGCs evaluated were calretinin IR (Fig. 1C) . In some cases, these CGCs were preferentially of larger size (24–36 µm in diameter), but there were also other cases showing mainly small calretinin-positive cells (17–21 µm in diameter).

Only few small CGCs (14–18 µm in diameter) were NPY IR (7/152 evaluated CGCs). Single larger CGCs (25–34 µm in diameter) revealed faint staining with antibodies against galanin (3/189 evaluated CGCs). Most of the neurons in NPY- and galanin-stained sections, however, were unstained. There was no staining of CGCs with the antibodies against TH, DBH, vesicular monoaminergic transporter (VMAT)-2, vesicular acetylcholine transporter (VAChT), substance P (SP), and CGRP (total number of evaluated CGCs: 1340).

Ultrastructural investigations showed, that the CGCs appeared as typical neurons with a large nucleus containing light-appearing chromatin and a clear nucleolus and a cytoplasm containing ribosomes, stacks of rough endoplasmic reticulum, and mitochondria (Fig. 2A) . In CGCs of aged donor eyes, lipofuscin granules were frequently seen within the cytoplasm of the neurons. numerous vesicle-filled boutons were present around the CGC, forming synaptic contacts with the neuron (Fig. 2B) . The surface of the CGCs toward the surrounding connective tissue space was only incompletely covered by glial cell processes. In places, the basement membrane of the neurons directly contacted the adjacent collagen fibrils (Fig. 2C) without forming specialized contacts, such as with hemidesmosomes. Those CGCs arranged in doublets or clusters of even more cells were partly apposed to each other without being completely separated by glial cell processes (Fig. 2D) . Neither single cells nor groups of CGCs were supplied by or adjacent to capillaries. All CGCs were embedded in a nerve fiber plexus.



View larger version (227K):
[in this window]
[in a new window]
  		FIGURE 2. Ultrastructural appearance of human CGCs. (A) The nucleus (ZK) contained light-appearing chromatin, and the cytoplasm contained stacks of rough endoplasmic reticulum (rER) and mitochondria (M). (B) Numerous vesicle-filled boutons (arrows) were present around the CNC, forming synaptic contacts (S) with the neuron. (C) In places, the basement membrane of the neurons directly contacted the adjacent collagen fibrils (). (D) Those CGCs arranged in doublets or clusters of even more cells were partly apposed to each other without being separated by glial cell processes (arrows). Original magnifications: (A) x3,600; (B) x26,000; (C) x17,000; (D) x25,000.

 
Neuronal Boutons Apposed to CGCs
Staining of the choroid with antibodies against synaptophysin revealed the presence of synaptic contacts around each CGC, independent of size (cell diameter) and localization (choroidal versus suprachoroidal; in the choroidal stroma versus in the ciliary nerves). However, not all boutons around the CGCs revealed the same neurochemical composition (Table 2) .


View this table:
[in this window]
[in a new window]
  		TABLE 2. Staining of CGCs and Surrounding Boutons with the Neuronal Markers Used in the Study

 
All CGCs showed appositions of nNOS and VIP IR boutons (Fig. 3A) . Single boutons also stained for NPY (Fig. 3B) . Calretinin IR boutons were seen only at CGCs that were not calretinin IR themselves (Fig. 3C) . However, only 42 of the 64 calretinin-negative CGCs investigated had close calretinin-positive contacts. The calretinin-negative CGCs that showed no calretinin IR boutons were always next to calretinin-positive CGCs (Fig. 3D) . No colocalization occurred with antibodies against calretinin and VMAT-2 (Fig. 4A) , whereas some but not all boutons showed colocalization with antibodies against calretinin and VAChT (Fig. 4B) .



View larger version (111K):
[in this window]
[in a new window]
  		FIGURE 3. Micrographs of human choroidal ganglion cells stained with antibodies against (A) VIP), (B) NPY, and (C, D) calretinin. Note the numerous positive appositions of VIP and NPY boutons. (C) Calretinin-positive boutons were seen in proximity with CGCs that did not stain for calretinin themselves. (D) Two calretinin-negative CGCs (arrowheads) that showed no calretinin-positive boutons but lipofuscin granules (arrows) were next to a calretinin-positive CGC (). Original magnification, x400

 


View larger version (53K):
[in this window]
[in a new window]
  		FIGURE 4. (A) Double immunostaining for calretinin (red) and vesicular monoaminergic transporter 2 (green) showed no colocalization in boutons. (B) Double-immunostaining for calretinin (red) and vesicular acetylcholine transporter (green) showed only slight colocalization in boutons (yellow). The intracellular yellow granules in the double-stained images refer to autofluorescence of the lipofuscin (arrows), also marked by arrows in the single-stained images. Original magnification: (A) x400; (B) x630.

 
Approximately half of the CGCs showed an intense innervation of TH-positive nerve fibers. One third of the TH-IR boutons around the CGCs were colocalized with antibodies against VMAT-2, and others showed colocalization with antibodies against VAChT. No staining of boutons in close apposition to the CGCs was seen using antibodies against galanin, SP, and CGRP.

Innervation of the Choroidal Vasculature
A dense perivascular network of nerve fibers was seen around the arteries, arterioles, and veins when using antibodies against VAChT, nNOS, or VIP as the marker for parasympathetic, and TH, DBH, VMAT-2, or NPY as the marker for sympathetic nerve fibers. The larger arteries were also accompanied by CGRP-positive nerve fibers. SP-positive nerve fibers formed a fine network in the outer choroid without showing close affiliation to the vessels but rather contacting cells in the choroidal stroma. In the inner choroid, only single TH/VMAT-2/NPY-positive nerve fibers reached the choriocapillary layer, forming a fine network at the level of the precapillary arterioles.

Innervation of NVSMCs
NVSMCs were identified by their general content of {alpha}-smooth muscle actin. A subgroup of these cells (15%) also stained for smooth muscle myosin, as described previously.11

The general presence of nerve fibers in close proximity to NVSMCs was detected by double staining of choroidal sections and wholemounts with antibodies against {alpha}-smooth muscle actin and PGP 9.5. However, not every muscle cell was innervated separately. Approximately 20% of all NVSMCs showed close contact to nerve fibers. As the choroid is densely innervated and many NVSMCs also run parallel with nerve fiber bundles, the number of innervated cells could only be estimated. Double staining with antibodies against smooth muscle myosin and PGP 9.5 showed that close contact of the NVSMCs with nerve fibers was not exclusively characteristic of the myosin-containing NVSMCs.

Specific neuronal markers that stained nerve fibers with boutons in close contact to the NVSMCs included NPY and VAChT. Choroidal wholemounts double stained for {alpha}-smooth muscle actin and NPY (Fig. 5) or {alpha}-smooth muscle actin and VAChT and investigated by confocal microscopy revealed that the same estimated number of NVSMCs as for PGP 9.5 received input from NPY- and VAChT-positive nerve fibers. All other antibodies tested, including nNOS, TH, VMAT-2, VIP, SP, and CGRP, showed no nerve fibers in close relation to the NVSMCs.



View larger version (152K):
[in this window]
[in a new window]
  		FIGURE 5. Confocal image of a human choroid section double stained with antibodies against {alpha}-smooth muscle {alpha}-actin (green) and NPY (red), showing the close contact of NPY IR boutons to some of the NVSMCs in the choroid (arrows).

 

   Discussion
Top
 Abstract
 Material and Methods
 Results
 Discussion
References
 
In the present study we showed that numerous CGCs stain not only for nNOS and VIP,1 2 12 but also show immunoreactivity for antibodies against calretinin. Single CGCs were NPY IR. Ultrastructurally, the CGCs showed an incomplete glial sheath and, in places, close contact to surrounding collagen fibrils. The CGCs were in close contact with numerous boutons staining for different neuronal markers, including synaptophysin, nNOS, VIP, NPY, TH, VMAT-2, VAChT, calretinin, and NPY. Because we observed NPY-positive nerve fibers supplying the NVSMCs, it is tempting to speculate that the NPY-positive CGCs may regulate the NVSMCs.

In mammals without a fovea centralis, the vasodilative innervation of the choroid derives from the sphenopalatine ganglion,13 14 15 16 17 18 19 similar to mammals with foveas, including humans. To some extent, the CGCs in the human choroid also show similarities to the neurons of the sphenopalatine ganglion. There, most of the neurons stain for nNOS and VIP,20 21 22 and single neurons stain for NPY.22 A colocalization of NPY and VIP is also reported for some neurons in the human sphenopalatine ganglion.23 However, in contrast to the mammalian sphenopalatine ganglion, where numerous neurons also contain acetylcholinesterase,24 choline acetyltransferase and acetylcholine,25 no staining for VAChT or choline acetyltransferase was present in human CGCs.4 The CGCs therefore differ from sphenopalatine ganglion neurons in regard to their cholinergic immunohistochemical staining. Whether this failure of staining in human tissue is due to the sensitivity of the transmitters or to a true functional diversity between CGCs and sphenopalatine ganglion neurons remains to be determined.

It is unknown, why primates have neurons in the choroid. In this context it is interesting to note that the CGCs reveal glia-free areas, covered only by a basement membrane, that show contact to the surrounding connective tissue. An incomplete glial sheath is typical for enteric neurons in the gut and gallbladder,26 27 but not for other autonomic ganglia.28 Direct exposure of enteric neurons to periganglionic matrix has been discussed in the context of a possible mechanosensory function.26 There exist electrophysiological data on direct mechanosensitivity of enteric neurons,29 30 and intrinsic primary afferent neurons in enteric ganglia have been characterized recently by both morphologic and electrophysiological methods.31 Furthermore, vagal afferent terminals in the gastrointestinal tract are typically associated with enteric ganglia32 where they are located immediately beneath the basement membrane facing the periganglionic collagen matrix.33 Their low threshold mechanosensory function has been elegantly demonstrated by recent electrophysiological studies.34 35 Thus, it is tempting to speculate that, in addition to motor neurons, choroid ganglia harbor sensory neurons, as do enteric ganglia, and that their intimate relationship to the periganglionic matrix hints of a mechanosensory subpopulation of CGCs.

Many of the processes issued by CGCs are targeted to choroidal arteries where they form a dense perivascular plexus. Although hitherto interpreted in favor of a vasomotor function,2 5 some of them may represent mechanosensory terminals similar to carotid and aortic baroreceptors of the IXth and Xth cranial nerves, respectively.36 37 In conjunction with indications for intrinsic CGC–CGC connections in both primates (this study, discussed below) and birds,8 this could be interpreted in terms of an intrinsic neuronal mechanism for regulation of choroidal blood flow.

Another hint of the possible existence of a mechanosensory subpopulation of CGCs is calretinin immunoreactivity in some of them. This calcium-binding protein is typically contained in low-threshold spinal mechanosensors (e.g., muscle spindles) in both rat and chicken,38 in vagal mechanosensors in the rat esophagus,39 and in intrinsic primary afferent type II neurons in the human small intestine. However, the predictive value of immunocytochemical neuronal markers for neuronal function should be discussed with great care because of significant species differences.41 42

The second major finding of this study was the characterization of the numerous synaptic contacts on the CGCs. Besides calretinin, several neurotransmitters were found in the synaptic boutons in close contact with the CGCs. Calretinin-, VIP-, and nNOS-positive boutons probably demonstrate an inter-CGCs connection, although they could also derive from the sphenopalatine ganglion. The distribution of cholinergic boutons differed markedly from that seen for VIP and nNOS. Because virtually all sphenopalatine ganglion neurons express one of these markers, we concluded that the source of the cholinergic boutons is most likely not only the sphenopalatine ganglion. nNOS-positive neurons also exist in the trigeminal ganglion,43 but they do not express VIP and most of the trigeminal neurons express SP and CGRP.44 As these markers do not stain CGCs synaptic boutons, the trigeminal ganglion seems to play no role in regulation of human CGCs. Most of the superior cervical ganglion neurons stain positively for NPY,44 noradrenalin, TH, and DBH.22 45 Most of the TH/VMAT-2 positive endings around the CGCs derive from this source, similar to the duck.9 These contacts point to a more complex regulation of the CGCs that is generally not common to other intrinsic neurons beside the enteric nervous system.46 Presumably these contacts are formed to restrain the vasoconstrictive effect of the sympathetic nerve fibers.

Within the ciliary ganglion, various neurons exist that also show great species differences. In the human, approximately 23% stain positively for TH,43 whereas only single cells stain for nNOS.47 All ciliary ganglion neurons are thought to be cholinergic. Therefore, the VAChT-positive–NOS-negative synaptic contacts on CGCs could also derive from this ganglion. As the ciliary ganglion mainly supplies the ciliary muscle, one can speculate that, during ciliary muscle contraction for accommodation, the CGCs receive a copy of this information and therefore can modulate the volume of the choroid to keep the fovea centralis in place. This could explain, why choroidal ganglion cells occur only in species with a well-developed accommodative system and a fovea centralis. In support of this evidence, one can add that the cholinergic nerve fibers are in close contact with the NVSMCs. In contrast to paraffin-embedded sections described in the literature,48 our careful examination of frozen serial sections revealed that the NVSMCs in the human choroid do not receive input from nNOS- or VIP-positive nerve fibers. Rather, they are innervated by NPY-VAChT–positive axons. However, CGCs may not represent the main source of these axons. This differs from the avian eye, where a clear innervation of NVSMCs deriving from the choroidal ganglion cells could be demonstrated.8 Human CGCs also do not have CGRP-positive endings being present in the avian eye and leading to the postulation of a local precentral reflex arc.9 10 Regarding these differences, the function of the CGCs in birds may be somewhat different from that in the human eye.

In conclusion, we found a rather homogenous staining pattern of CGCs in the human choroid that showed similarities to the pterygopalatine ganglion. In addition, ultrastructural findings and immunofluorescence for calretinin point to a possible mechanoreceptor-like function of the CGCs themselves, thus explaining the location of these neurons in the choroid proper. The target of the CGCs in the human eye is mainly the choroidal vasculature. This could recently be confirmed by intracellular staining of the processes of human CGCs with neurobiotin.49 The supply of the CGCs to the choroidal vasculature is regarded as supplementary to a direct vasodilative innervation of the sphenopalatine ganglion. Because of their complex synaptic input the CGCs seem to form a highly regulated intrinsic system that reacts not only to parasympathetic and sympathetic information, but as an integrated local vasoregulatory system for foveal vision during accommodation. The importance of the choroid for proper vision is also known during recovery from form-deprivation myopia in the foveated avian, tree shrew, and primate eye.50 51 52 Neuronal involvement of cholinergic, NO-, and VIP-ergic nerve fibers seem to play key roles in this process.53 54 55 Their source is not defined and may also include the CGCs.


   Footnotes
 
Supported by German Research Community SFB 539 BII,2.

Submitted for publication June 20, 2003; revised September 29, 2003; accepted October 26, 2003.

Disclosure: C.A. May, None; W. Neuhuber, None; E. Lütjen-Drecoll, None

The publication costs of this article were defrayed in part by page charge payment. This article must therefore be marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.

Corresponding author: Christian Albrecht May, Anatomisches Institut II, Universitätsstr. 19, D-91054 Erlangen, Germany; albrecht.may{at}anatomie2.med.uni-erlangen.de.


   References
Top
 Abstract
 Material and Methods
 Results
 Discussion
 References
 

  1. Bergua A, Jünemann A, Naumann GOH. NADPH-D reaktive choroidale Ganglienzellen beim Menschen. Klin Monatsbl Augenheilk. 1993;203:77–82.[Medline][Order article via Infotrieve]
  2. Flügel C, Tamm ER, Mayer B, Lütjen-Drecoll E. Species differences in choroidal vasodilative innervation: evidence for specific intrinsic nitrergic and VIP-positive neurons in the human eye. Invest Ophthalmol Vis Sci. 1994;35:592–599.[Abstract/Free Full Text]
  3. Tamm ER, Flügel-Koch C, Mayer B, Lütjen-Drecoll E. Nerve cells in the human ciliary muscle: ultrastructural and immunocytochemical characterization. Invest Ophthalmol Vis Sci. 1995;36:414–426.[Abstract/Free Full Text]
  4. May CA, Fuchs AV, Scheib M, Lütjen-Drecoll E. Characterization of nitrergic neurons in the porcine and human ciliary nerves. Invest Ophthalmol Vis Sci. 2002;43:581–586.[Abstract/Free Full Text]
  5. Flügel-Koch C, Kaufman P, Lütjen-Drecoll E. Association of a choroidal ganglion cell plexus with the fovea centralis. Invest Ophthalmol Vis Sci. 1994;35:4268–4272.[Abstract/Free Full Text]
  6. Bergua A, Mayer B, Neuhuber WL. Nitrergic and VIPergic neurons in the choroid and ciliary ganglion of the duck Anis carina. Anat Embryol. 1996;193:239–248.[Medline][Order article via Infotrieve]
  7. Cuthbertson S, Jackson B, Toledo C, et al. Innervation of orbital and choroidal blood vessels by the pterygopalatine ganglion in pigeons. J Comp Neurol. 1997;386:422–442.[CrossRef][ISI][Medline][Order article via Infotrieve]
  8. Schrödl F, Brehmer A, Neuhuber WL. Intrinsic choroidal neurons in the duck eye express galanin. J Comp Neurol. 2000;425:24–33.[CrossRef][ISI][Medline][Order article via Infotrieve]
  9. Schrödl F, Tines R, Brehmer A, Neuhuber WL. Intrinsic choroidal neurons in the duck eye receive sympathetic input: anatomical evidence for adrenergic modulation of nitrergic functions in the choroid. Cell Tissue Res. 2001;304:175–184.[CrossRef][ISI][Medline][Order article via Infotrieve]
  10. Schrödl F, Schweigert M, Brehmer A, Neuhuber WL. Intrinsic neurons in the duck choroid are contacted by CGRP-immunoreactive nerve fibres: evidence for a local pre-central reflex arc in the eye. Exp Eye Res. 2001;72:137–146.[CrossRef][ISI][Medline][Order article via Infotrieve]
  11. Flügel-Koch C, May CA, Lütjen-Drecoll E. Presence of a contractile cell network in the human choroid. Ophthalmologica. 1996;210:296–302.[ISI][Medline][Order article via Infotrieve]
  12. Miller AS, Coster DJ, Costa M, Furness JB. Substance P and vasoactive intestinal peptide immunoreactive nerves in the human and rat eye (Abstract). Neurosci Lett. 1982;8:S67.
  13. Uddman R, Alumets J, Ehinger B, Hakanson R, Loren I, Sundler F. Vasoactive intestinal peptide nerves in ocular and orbital structures of the cat. Invest Ophthalmol Vis Sci. 1980;19:878–885.[Abstract/Free Full Text]
  14. Butler JM, Ruskell GL, Cole DF, et al. Effects of VIIth (facial) nerve degeneration on vasoactive intestinal polypeptide and substance P levels in ocular and orbital tissues of the rabbit. Exp Eye Res. 1984;39:523–532.[CrossRef][ISI][Medline][Order article via Infotrieve]
  15. Ten Tusscher MP, Klooster J, Baljet B, Van der Werf F, Vrensen GF. Pre- and post-ganglionic nerve fibres of the pterygopalatine ganglion and their allocation to the eyeball of rats. Brain Res. 1990;517:315–323.[CrossRef][ISI][Medline][Order article via Infotrieve]
  16. Beckers HJ, Klooster J, Vrensen GF, Lamers WP. Facial parasympathetic innervation of the rat choroid, lacrimal glands and ciliary ganglion: an ultrastructural pterygopalatine tracing and immunohistochemical study. Ophthalmic Res. 1993;25:319–330.[ISI][Medline][Order article via Infotrieve]
  17. Yamamoto R, Bredt DS, Snyder SH, Stone RA. The localization of nitric oxide synthase in the rat eye and related cranial ganglia. Neuroscience. 1993;54:189–200.[CrossRef][ISI][Medline][Order article via Infotrieve]
  18. Klooster J, Beckers HJ, Ten Tusscher MP, Vrensen GF, van der Want JJ, Lamers WP. Sympathetic innervation of the rat choroid: an autoradiographic tracing and immunohistochemical study. Ophthalmic Res. 1996;28:36–43.[ISI][Medline][Order article via Infotrieve]
  19. Steinle JJ, Krizsan-Agbas D, Smith PG. Regional regulation of choroidal blood flow by autonomic innervation in the rat. Am J Physiol. 2000;279:R202–R209.[ISI]
  20. Motosugi H. Immunohistochemical observation of neurotransmitters in rat and human pterygopalatine ganglia [in Japanese]. Nippon Jibiinkoka Gakkai Kaiho. 1993;96:936–945.[Medline][Order article via Infotrieve]
  21. Hanazawa T, Tanaka K, Chiba T, Konno A. Distribution and origin of nitric oxide synthase-containing nerve fibers in human nasal mucosa. Acta Otolaryngol. 1997;117:735–737.[Medline][Order article via Infotrieve]
  22. Grimes PA, Koeberlein B, Tigges M, Stone RA. Neuropeptide Y-like immunoreactivity localizes to preganglionic axon terminals in the rhesus monkey ciliary ganglion. Invest Ophthalmol Vis Sci. 1998;39:227–232.[Abstract/Free Full Text]
  23. Lacroix JS, Anggard A, Hokfelt T, O’Hare MM, Fahrenkrug J, Lundberg JM. Neuropeptide Y: presence in sympathetic and parasympathetic innervation of the nasal mucosa. Cell Tissue Res. 1990;259:119–128.[CrossRef][ISI][Medline][Order article via Infotrieve]
  24. Uddman R, Malm L, Sundler F. Peptide containing nerves in the nasal mucosa. Rhinology. 1981;19:75–79.[Medline][Order article via Infotrieve]
  25. Suzuki N, Hardebo JE. The cerebrovascular parasympathetic innervation. Cerebrovasc Brain Metab Rev. 1993;5:33–46.[ISI][Medline][Order article via Infotrieve]
  26. Gabella G. On the ultrastructure of the enteric nerve ganglia. Scand J Gastroenterol Suppl. 1982;71:15–25.[Medline][Order article via Infotrieve]
  27. Cornbrooks EB, Pouliot WA, Mawe GM. Structure of neurons and ganglia of the guinea-pig gallbladder: an immunohistochemical study. J Comp Neurol. 1992;317:45–56.[CrossRef][ISI][Medline][Order article via Infotrieve]
  28. Baluk P, Fujiwara T, Matsuda S. The fine structure of the ganglia of the guinea-pig trachea. Cell Tissue Res. 1985;239:51–60.[CrossRef][ISI][Medline][Order article via Infotrieve]
  29. Wood JD. Physiology of the enteric nervous system. Johnson LR eds. 2nd ed. Physiology of the Gastrointestinal Tract. 1987;1:67–109. Raven Press New York.
  30. Kunze WA, Clerc N, Furness JB, Gola M. The soma and neurites of primary afferent neurons in the guinea-pig intestine respond differentially to deformation. J Physiol. 2000;526:375–385.[Abstract/Free Full Text]
  31. Furness JB, Kunze WAA, Bertrand PP, Clerc N, Bornstein JC. Intrinsic primary afferent neurons of the intestine. Prog Neurobiol. 1998;54:1–18.[CrossRef][ISI][Medline][Order article via Infotrieve]
  32. Phillips RJ, Powley TL. Tension and stretch receptors in gastrointestinal smooth muscle: re-evaluating vagal mechanoreceptor electrophysiology. Brain Res Brain Res Rev. 2000;34:1–26.[CrossRef][Medline][Order article via Infotrieve]
  33. Neuhuber WL. Sensory vagal innervation of the rat esophagus and cardia: a light and electron microscopic anterograde tracing study. J Auton Nerv Syst. 1987;20:243–255.[CrossRef][ISI][Medline][Order article via Infotrieve]
  34. Zagorodnyuk VP, Brookes SJ. Transduction sites of vagal mechanoreceptors in the guinea pig esophagus. J Neurosci. 2000;20:6249–6255.[Abstract/Free Full Text]
  35. Zagorodnyuk VP, Chen BN, Brookes SJ. Intraganglionic laminar endings are mechano-transduction sites of vagal tension receptors in the guinea-pig stomach. J Physiol. 2001;534:255–268.[Abstract/Free Full Text]
  36. Hohler B, Mayer B, Kummer W. Nitric oxide synthase in the rat carotid body and carotid sinus. Cell Tissue Res. 1994;276:559–564.[ISI][Medline][Order article via Infotrieve]
  37. Thames MD, Smith ML, Dibner-Dunlap ME, Minisi AJ. Reflexes governing autonomic outflow to the heart. Shepherd JT Vatner SF eds. Nervous Control of the Heart. 1996;295–327. Harwood Academic Publishers Amsterdam.
  38. Duc C, Barakat-Walter I, Droz B. Innervation of putative rapidly adapting mechanoreceptors by calbindin- and calretinin-immunoreactive primary sensory neurons in the rat. Eur J Neurosci. 1994;6:264–271.[CrossRef][ISI][Medline][Order article via Infotrieve]
  39. Dütsch M, Eichhorn U, Wörl J, Wank M, Berthoud HR, Neuhuber WL. Vagal and spinal afferent innervation of the rat esophagus: a combined retrograde tracing and immunocytochemical study with special emphasis on calcium-binding proteins. J Comp Neurol. 1998;398:289–307.[CrossRef][ISI][Medline][Order article via Infotrieve]
  40. Brehmer A, Schrödl F, Neuhuber W. Quantitative morphological and immunohistochemical assessment of putative primary afferent (type II) versus type V myenteric neurons of human small intestine (Abstract). Neurogastroenterol Motil. 2003;15:217A.
  41. Timmermans JP, Hens J, Adriaensen D. Outer submucous plexus: an intrinsic nerve network involved in both secretory and motility processes in the intestine of large mammals and humans. Anat Rec. 2001;262:71–78.[CrossRef][Medline][Order article via Infotrieve]
  42. Brehmer A, Schrödl F, Neuhuber W. Morphological phenotyping of enteric neurons using neurofilament immunohistochemistry renders chemical phenotyping more precise in porcine ileum. Histochem Cell Biol. 2002;117:257–263.[CrossRef][ISI][Medline][Order article via Infotrieve]
  43. Kirch W, Neuhuber W, Tamm ER. Immunohistochemical localization of neuropeptides in the human ciliary ganglion. Brain Res. 1995;681:229–234.[CrossRef][ISI][Medline][Order article via Infotrieve]
  44. Matsumoto Y, Tanabe T, Ueda S, Kawata M. Immunohistochemical and enzyme histochemical studies of peptidergic, aminergic and cholinergic innervation of the lacrimal gland of the monkey (Macaca fuscata). J Autonom Nerv Syst. 1992;37:207–214.[CrossRef][ISI][Medline][Order article via Infotrieve]
  45. Tajti J, Moller S, Uddman R, Bodi I, Edvinsson L. The human superior cervical ganglion: neuropeptides and peptide receptors. Neurosci Lett. 1999;263:121–124.[CrossRef][ISI][Medline][Order article via Infotrieve]
  46. Baluk P, Gabella G. Innervation of the guinea pig trachea: a quantitative morphological study of intrinsic neurons and extrinsic nerves. J Comp Neurol. 1989;285:117–132.[CrossRef][ISI][Medline][Order article via Infotrieve]
  47. Demer JL, Poukens V, Miller JM, Micevych P. Innervation of extraocular pulley smooth muscle in monkeys and humans. Invest Ophthalmol Vis Sci. 1997;38:1774–1785.[Abstract/Free Full Text]
  48. Poukens V, Glasgow BJ, Demer JL. Nonvascular contractile cells in sclera and choroid of humans and monkeys. Invest Ophthalmol Vis Sci. 1998;39:1765–1774.[Abstract/Free Full Text]
  49. Schrödl F, De Laet A, Tassignon MJ, et al. Intrinsic choroidal neurons in the human eye: projections, targets and basic electrophysiological data. Invest Ophthalmol Vis Sci. 2003;44:3705–3712.[Abstract/Free Full Text]
  50. Wildsoet C, Wallman J. Choroidal and scleral mechanisms of compensation for spectacle lenses in chicks. Vision Res. 1995;35:1175–1194.[CrossRef][ISI][Medline][Order article via Infotrieve]
  51. Wallman J, Wildsoet C, Xu A, et al. Moving the retina: choroidal modulation of refractive state. Vision Res. 1995;35:37–50.[CrossRef][ISI][Medline][Order article via Infotrieve]
  52. Hung LF, Wallman J, Smith EL., III. Vision-dependent changes in the choroidal thickness of macaque monkeys. Invest Ophthalmol Vis Sci. 2000;41:1259–1269.[Abstract/Free Full Text]
  53. Fujikado T, Kawasaki Y, Fujii J, et al. The effect of nitric oxide synthase inhibitor on form-deprivation myopia. Curr Eye Res. 1997;16:992–996.[CrossRef][ISI][Medline][Order article via Infotrieve]
  54. Seltner RL, Stell WK. The effect of vasoactive intestinal peptide on development of form deprivation myopia in the chick: a pharmacological and immunocytochemical study. Vision Res. 1995;35:1265–1270.[CrossRef][ISI][Medline][Order article via Infotrieve]
  55. Pendrak K, Lin T, Stone RA. Ciliary ganglion choline acetyltransferase activity in avian macrophthalmos. Exp Eye Res. 1995;60:237–243.[CrossRef][ISI][Medline][Order article via Infotrieve]




This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via ISI Web of Science (12)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by May, C. A.
Right arrow Articles by Lütjen-Drecoll, E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by May, C. A.
Right arrow Articles by Lütjen-Drecoll, E.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS