- Research article
- Open Access
Effects of NGF, NT-3 and GDNF family members on neurite outgrowth and migration from pelvic ganglia from embryonic and newborn mice
© Stewart et al; licensee BioMed Central Ltd. 2008
Received: 11 April 2008
Accepted: 25 July 2008
Published: 25 July 2008
Pelvic ganglia are derived from the sacral neural crest and contain both sympathetic and parasympathetic neurons. Various members of the neurotrophin and GDNF families of neurotrophic factors have been shown to play important roles in the development of a variety of peripheral sympathetic and parasympathetic neurons; however, to date, the role of these factors in the development of pelvic ganglia has been limited to postnatal and older ages. We examined the effects of NGF, NT-3, GDNF, neurturin and artemin on cell migration and neurite outgrowth from explants of the pelvic ganglia from embryonic and newborn mice grown on collagen gels, and correlated the responses with the immunohistochemical localization of the relevant receptors in fixed tissue.
Cell migration assays showed that GDNF strongly stimulated migration of tyrosine hydroxylase (TH) cells of pelvic ganglia from E11.5, E14.5 and P0 mice. Other factors also promoted TH cell migration, although to a lesser extent and only at discrete developmental stages. The cells and neurites of the pelvic ganglia were responsive to each of the GDNF family ligands – GDNF, neurturin and artemin – from E11.5 onwards. In contrast, NGF and NT-3 did not elicit a significant neurite outgrowth effect until E14.5 onwards. Artemin and NGF promoted significant outgrowth of sympathetic (TH+) neurites only, whereas neurturin affected primarily parasympathetic (TH-negative) neurite outgrowth, and GDNF and NT-3 enhanced both sympathetic and parasympathetic neurite outgrowth. In comparison, collagen gel assays using gut explants from E11.5 and E14.5 mice showed neurite outgrowth only in response to GDNF at E11.5 and to neurturin only in E14.5 mice.
Our data show that there are both age-dependent and neuron type-dependent differences in the responsiveness of embryonic and neo-natal pelvic ganglion neurons to growth factors.
The pelvic ganglia provide the majority of autonomic innervation to the urogenital organs and part of the extrinsic innervation of the lower bowel [1–3]. In humans, the plexus is extensive and is frequently injured during pelvic surgical procedures [4–7]. The development of regenerative therapies may be facilitated by improved knowledge of the processes that occur during the normal development of the pelvic neuronal circuits. In mice and rats, the structure of the pelvic ganglia is simpler than in humans, and consists of paired, morphologically discrete, major pelvic ganglia . Hence, developing rodent pelvic ganglia are an accessible system in which to study developmental processes involved in formation of pelvic autonomic circuits .
Unlike other autonomic ganglia, the pelvic ganglia are comprised of a mixture of sympathetic and parasympathetic post-ganglionic neurons [1, 2, 10]. Both sympathetic and parasympathetic post-ganglionic neurons of pelvic ganglia are derived from the sacral neural crest [11–14]. In embryonic mice, sacral neural crest cells migrate ventrally and coalesce into aggregates between the distal hindgut and the urogenital sinus [11, 15]. Some sacral neural crest cells contribute neurons and glial cells to distal regions of the gut ; these cells reside transiently within the pelvic plexus primordia for around 3 days before entering the hindgut [11, 15–17].
The factors that regulate the migration of sacral neural crest cells and the axonal projections of the developing pelvic ganglia remain largely unknown. In contrast, factors regulating migration and axon extension in other components of the autonomic nervous system including the enteric nervous system, sympathetic ganglia, and cranial parasympathetic ganglia have been well studied [18–28]. As neural crest from different axial levels possess different developmental capabilities, and in vitro, differ in their response to some factors , the mechanisms regulating cell differentiation in the sacral neural crest-derived sympathetic and parasympathetic neurons may be different from those in more rostral sympathetic and parasympathetic ganglia.
Axon extension and neural migration in the peripheral nervous system is influenced by numerous neurotrophic factors. The best characterized group is the neurotrophin family that consists of four members – nerve growth factor (NGF), neurotrophin-3 (NT-3), brain-derived neurotrophic factor (BDNF), and neurotrophin-4 (NT-4). There are three different tyrosine kinase receptors that mediate the effects of neurotrophins – TrkA, TrkB and TrkC . NGF binds and activates the TrkA receptor, BDNF and NT-4 both signal through TrkB, and NT-3 activates TrkC. While NGF, BDNF and NT-4 show very little receptor promiscuity, NT-3 can under some circumstances also interact with the TrkA and TrkB receptors .
The GDNF family ligands (GFLs) – glial cell-line-derived neurotrophic factor (GDNF), neurturin (NRTN) and artemin (ART) are important neurotrophic factors for many types of neurons including central motor, dopamine, and noradrenaline neurons as well as for sub-populations of peripheral autonomic and sensory neurons [32–42]. All GFLs signal through a receptor complex composed of a common signaling subunit, the Ret receptor tyrosine kinase. The ligand specificity is determined by a co-receptor subunit – GDNF, neurturin and artemin bind preferentially to GFRα1, GFRα2 and GFRα3 respectively . GFRα receptors are usually bound to the plasma membrane, but can also be cleaved to produce soluble forms .
A number of studies have examined the expression of neurotrophic factor receptors by pelvic ganglion neurons and ligand expression in their targets in post-natal and adult animals. A variety of neurotrophic factors including neurotrophins and members of the GDNF family are expressed in tissues innervated by pelvic neurons including the colon, penis, vas deferens and bladder [45–51]. Furthermore, there are changes in pelvic neurons and their innervation of targets in neurotrophic factor ligand- or receptor-deficient mice; in mice lacking neurturin, or its receptor GFRα2, there are defects in the parasympathetic innervation of some of the reproductive organs [3, 50, 52]. In vitro studies have shown that neurturin stimulates soma growth and promotes neurite extension of dissociated parasympathetic neurons from adult male rats . However, these studies demonstrate that neurturin is only essential in some pelvic target organs.
While the role of neurotrophins and neurturin in the adult [49–58], and more recently, postnatal  pelvic plexus has been examined, there is relatively little known about the role of different neurotrophic factors in the pre-natal development of the pelvic ganglia. In mice, GDNF and neurturin are expressed by a variety of pelvic tissues at mid-embryonic ages including the colon (from E10), genital tubercle (from E10) and urogenital sinus (from E14), ovary (from E14) and testicle (from E14) , but the expression of neurotrophins and artemin does not appear to have been examined pre-natally.
In the present study, we report the effects of neurotrophin and GFL signalling on cell migration and neurite outgrowth of parasympathetic and sympathetic neurons in pelvic ganglia from embryonic and newborn mice and correlate the responses with the expression of the corresponding receptors. Our data show that GDNF family members have actions from early stages (E11.5) of pelvic plexus development, while neurotrophins do not exert an influence until later. As in older animals, sympathetic and parasympathetic neurons in pelvic ganglia from embryonic and newborn mice show differences in their responses to a number of neurotrophic factors.
Embryonic C57/Bl6 mice were used for all explant culture experiments. Mice in which the expression of GFP was driven by the rat tyrosine hydroxylase (TH) promoter  were used for receptor localisation studies. TH-GFP mice were on a C57/BL6 background. The genotype of adult TH-GFP mice was determined by PCR using the primers and conditions previously reported . Male mice heterozygous for the TH-GFP allele (THGFP/+ mice) were mated to wild-type (C57/BL6) females. To distinguish THGFP/+ from wild-type embryos, the sympathetic chain of each embryo was examined under a fluorescence microscope to determine if GFP+ cells were present; only THGFP/+ embryos were used. Timed pregnant mice were killed by cervical dislocation. The morning on which a copulatory plug was observed was designated E0.5. All procedures were approved by the University of Melbourne Animal Experimentation Ethics Committee.
Pelvic plexus explants grown on collagen gels
The location of pelvic plexus primordium in E11.5 and E14.5 mice has been described previously [11, 15]. In E11.5 mice, the plexus primordia are dorso-lateral to the distal hindgut, and in E14.5 mice, they are ventro-lateral to the distal hindgut. In P0 male mice, discrete ganglia are located on the dorsal surface of the prostate gland, and can be recognized macroscopically [11, 15]. Connective tissue containing pelvic plexus primordia (E11.5, E14.5) or ganglia (P0) were dissected from E11.5, E14.5 and P0 mice and placed in culture medium (DMEM containing 10% foetal bovine serum, 2 mM glutamine, 0.075% sodium bicarbonate and penicillin/streptomycin sulfate solution), and were grown on collagen gels as described previously [61, 62]. Briefly, acidic collagen solution (4 mg/ml; Upstate, CA, USA) was restored to normal osmolality with 5 × Dulbecco's modified Eagle's medium (DMEM) and normal pH with 200 mM NaOH, on ice. This solution was diluted to 1 mg/ml with culture medium. Growth factor was added to the collagen solution prior to gelling to give a final concentration of 100 ng/ml GDNF, artemin, neurturin or NGF; or 40 ng/ml NT-3 (Peprotech, NJ, USA). These concentrations are based on previous studies that have examined the responses of sympathetic and enteric neurons from embryonic and post-natal mice in vitro [61, 63, 64]. Each explant contained an entire ganglion. Transverse slices from E11.5 midgut and E14.5 hindgut, as well as dorsal root ganglia from E11.5, E14.5 or P0 mice, were also grown on control and growth-factor impregnated gels.
Immunohistochemical analysis of cryosections
Primary and secondary antibodies
Sheep anti-tyrosine hydroxylase
Chemicon, Temecula, CA, USA
Jackson Immunoresearch, West Grove, PA, USA
Covance Research, Berkeley, CA, USA
Dr Miles Epstein; 
anti human-Texas Red
Rockland Immunochemicals, Gilbertsville, PA, USA
Molecular Probes, Eugene, OR, USA
Goat anti-GFRα1, GFRα2 or GFRα3
R&D Systems, Minneapolis, MN, USA
Dr Louis Reichardt; 
Dr Thomas Müller; 
Quantification of process outgrowth and cell migration
Explants grown on collagen gels were imaged under a Leica MZ16F fluorescence stereomicroscope. Explants were immunostained using antibodies to Tuj-1 and TH. Tuj-1 immunostaining will identify all neurites and TH immunostaining will identify the cell bodies and neurites of most sympathetic neurons (see Discussion). To quantify cell and neurite outgrowth from collagen gel explants, a feathered, Otsu-algorithm thresholded mask was applied to each channel, excluding the explant, to eliminate noise from regions without outgrowth (ImageJ and Adobe Photoshop, CA, USA) as described previously . Three thresholded images were then produced for quantification corresponding to Tuj-1 fibres, TH-fibres and TH-cells. The total area of stained pixels was obtained, as an estimate of the total number of cells/fibres outside the explant. The quantification of Tuj-1 fibres and TH-fibres provided information about the area occupied by stained fibres outside the explant, but do not provide any information about the length of individual fibres or intensity of immunostaining. To estimate neurite outgrowth from parasympathetic neurons in the explants, the area of TH immunostaining was subtracted from the area of Tuj-1 immunostaining. The quantification of TH+ cell bodies separately from TH-fibres was possible due to TH+ cell bodies possessing an increased intensity of immunofluorescence compared to TH+ fibres, allowing their differential selection by thresholding. The quantification of TH+ cells outside of the explants provided information about the area occupied by TH+ cell bodies outside the explants, but do not provide any information about the distance of the TH+ cell bodies from the explants. TH+ cells had to be greater than one cell body diameter away from the explant to be considered outside of the explant. Measurements were made using ImageJ (NIH, USA). Results are reported as mean ± standard error of the mean. Statistical analyses were performed using one way ANOVAs followed by Dunnett's post-hoc tests. A p value of < 0.05 was deemed significant. The data for each age and each factor are based on analysis of a minimum of 3 experiments and a minimum of 7 explants.
Response of pelvic plexus neurons to neurotrophic factors
In explants of pelvic plexus primordium from E11.5 mice, parasympathetic fibre outgrowth was significantly increased by both GDNF and neurturin (12-fold and 13-fold change compared to control explants, respectively; p < 0.01), whereas artemin did not elicit a significant response (Fig. 1A). Neither NGF nor NT-3 affected the parasympathetic fibre response (Fig. 1A). We observed a significant increase in outgrowth of TH fibres in the presence of both GDNF and artemin (4-fold and 3.5-fold, respectively; p < 0.01; Figs. 1B, 3B' and 3C'), but not in the presence of neurturin, NGF or NT-3 (Figs. 1B and 3D'). Significant increases in TH+ cell migration were only observed in the presence of GDNF and artemin (2-fold and 1.5-fold, respectively; p < 0.05; Fig. 2A).
Parasympathetic fibre outgrowth was significantly increased by GDNF (17-fold, p < 0.01) and neurturin (9-fold, p < 0.05; Fig. 1C). Unlike E11.5 explants, NT-3 induced a significant parasympathetic outgrowth from E14.5 explants (6-fold, p < 0.05; Fig. 1C). NGF and artemin did not promote parasympathetic outgrowth from E14.5 explants. GDNF and artemin no longer stimulated a significant TH+ fibre outgrowth, whereas increased TH+ fibre outgrowth was observed in response to neurturin, NGF, and NT-3 (3.5-fold, 3-fold, and 3-fold, respectively; p < 0.05; Fig. 1D). In the presence of NT-3, neurites appeared to be more fasciculated than in control explants or explants grown in the presence of the other growth factors. In E14.5 explants, GDNF continued to elicit TH+ cell migration (4-fold, p < 0.01; Fig. 2B). Neurturin and NGF were also able to elicit significant TH+ cell migration (3-fold, p < 0.05; and 2-fold, p < 0.01; respectively; Fig. 2B). However, unlike E11.5 explants, no significant TH+ cell migration was observed in response to artemin, and, despite inducing TH+ fibre outgrowth at this age, NT-3 did not promote TH+ cell migration (Fig. 2B).
A number of differences in the response of pelvic ganglia explants to the various growth factors were observed in P0 explants compared to E11.5 and E14.5 explants. Parasympathetic fibre outgrowth continued to be stimulated in response to both neurturin and NT-3 (8.5-fold and 12-fold, respectively; p < 0.05; Fig. 1E). However, GDNF no longer produced a parasympathetic fibre outgrowth response (Fig. 1E). NT-3 stimulated TH+ fibre outgrowth (3-fold; p < 0.05; Figs. 1F and 4D'); and, similar to their effect on E11.5 but not E14.5 explants, GDNF and artemin elicited significant TH+ fibre outgrowth responses from P0 explants (3-fold and 2.5-fold, respectively; p < 0.05; Figs. 1F and 4B'). All of the growth factors except NGF induced significant increases in TH+ cell migration (GDNF: 5.5-fold, NT-3: 4.5-fold, p < 0.01; neurturin: 2.5-fold, artemin: 4.5-fold, p < 0.05; Fig. 2C).
Response of E11.5 midgut and E14.5 hindgut explants to NT-3, NGF and GDNF family members
As previously shown , E11.5 and E14.5 gut explants grown on control gels (devoid of any neurotrophic factor) or in the presence of artemin, exhibit little or no neurite outgrowth (Fig. 5A); which is in contrast to pelvic plexus explants, which show some basal level of neurite extension in the absence of added neurotrophic factor. We observed a significant neurite outgrowth response to GDNF from E11.5 midgut slices (GDNF: 4-fold, p < 0.05; Fig. 5A). At E14.5, only neurturin induced significant neurite outgrowth (2.5-fold, p < 0.05) and there was little or no neurite outgrowth in response to GDNF (Fig. 5B). Although TrkC is expressed by a sub-population of neural crest derived cells in the gut and NT-3 has effects on differentiation , the effects of NGF and NT-3 on neurite outgrowth from gut slices has not been previously examined. Neither NGF nor NT-3 elicited a significant increase in total (Tuj-1+) neurite outgrowth at either E11.5 or E14.5 (Fig. 5A and 5B, respectively).
Expression of receptors for NGF, NT-3 and GDNF family members during development of pelvic ganglia
Expression of receptors for NGF, NT-3 and GDNF family members during development of pelvic ganglia
The pelvic plexus primordium is now located ventrolateral to the gut and dorsolateral to the urogenital sinus . A sub-population of the Hu+ cells was also TH+. TrkA staining was first evident at this stage and was present primarily on the Hu+/TH+ cells, although some Hu+/TH- cells also were TrkA+ (data not shown). Similarly, Hu+/TH+ cells were found to show strong TrkC immunostaining, but no TrkC staining was observed on the Hu+/TH- sub-population of cells (data not shown). GFRα2 immunostaining was also present primarily on the Hu+/TH+ sub-population of cells, with most of the Hu+/TH- population only weakly GFRα2+. By contrast, GFRα1 was localised primarily to a subgroup of the Hu+/TH- cells, with only weak GFRα1 staining found on the Hu+/TH+ sub-population (data not shown). GFRα3 staining was uniformly weak across all Hu+ cells (data not shown).
We have used collagen gel assays to investigate the role of the GFLs and neurotrophins in pelvic plexus development in embryonic and newborn mice. Our data show that neurons in the pelvic plexus primordium of E11.5 mice show neurite outgrowth and cell migration responses to GFLs. By contrast, an effect of the neurotrophins was not seen until E14.5. Most of the sympathetic neurons in pelvic ganglia are TH+ . To estimate neurite outgrowth from parasympathetic neurons in the explants in the current study, the TH staining was subtracted from the Tuj-1 staining. A caveat of these methods is that definitions of "sympathetic" and "parasympathetic" should be based on neuroanatomical inputs rather than chemistry . For example, there are some TH-negative sympathetic neurons in pelvic ganglia  and thus a small number of TH-negative neurites analysed in the current study are likely to arise from sympathetic neurons. Our data show that both the sympathetic (TH+) and parasympathetic (TH-negative) sub-populations of neurons are responsive to GDNF and NT-3, sympathetic neurons are primarily responsive to artemin and NGF, while parasympathetic neurons are mainly responsive to neurturin.
Effects of neurotrophic factors on pelvic plexus cell migration
Of the receptor components studied, only GFRα1 was found to be expressed on Hu-negative sacral crest-derived pelvic plexus cells at E11.5. These cells are probably cells of the neural crest-derived progenitor pool, but may also be glial precursors. As all other growth factor receptors were only found on Hu+ cells, it appears that only differentiated neurons are responsive to NGF, NT-3, artemin and neurturin. GDNF-GFRα1 signaling could therefore potentially regulate the very early stages of pelvic ganglia formation, with possible actions on guidance, differentiation, proliferation or survival of the undifferentiated sacral neural crest cells.
GDNF exhibited the most potent chemotactic action on cell migration of pelvic plexus neurons of all the factors examined; GDNF stimulated migration of TH+ cells from pelvic plexus explants at E11.5, E14.5 and P0 mice. The finding that GDNF produces significant TH+ cell migration at all stages is surprising, as TH+ cells did not express detectable levels of GFRα1. There are three possible explanations: first, the migration-promoting action of GDNF is not through its canonical receptor GFRα1. GFRα2 is expressed by TH+ cells, and it has been reported that, in vitro, GDNF can actively signal through binding to GFRα2 . However, neurturin, which most strongly activates the GFRα2 receptor, does not elicit a significant cell migration response at E11.5, and thus this possibility appears unlikely. Second, GDNF may act on the Hu-/TH- and/or Hu+/TH- sub-populations of cells, which do express GFRα1; these cells migrate in response to GDNF and then subsequently up-regulate TH expression. Finally, the number of GFRα1 receptors required to mediate a biological response might be below the detection threshold for immunohistochemical detection.
The timing of effect of the other growth factors on TH+ cell migration also gives the latter explanation further credence, as in each case the stages at which TH+ cell migration occurred correlated with the expression of the relevant receptors on the Hu+/TH- sub-population, but does not correlate with the expression of the relevant receptors on the Hu+/TH+ sub-population. Further studies are required to examine the migratory ability of Hu+/TH+, Hu+/TH- and Hu-/TH- cells.
Responses to neurotrophins
NGF is widely expressed within the target pelvic organs of neurons of the pelvic ganglia [49, 72–78]; and the neurotrophin receptors trkA and p75 are expressed by adult noradrenergic pelvic ganglion neurons [49, 54], as would be expected for NGF-sensitive neurons [79, 80]. Furthermore, in mice in which both the NGF and Bax genes were knocked-out to permit the role of NGF in target innervation to be determined separately from the role of NGF in survival, there were impairments in the density of sympathetic nerves in the urinary bladder, ureter and gonads, demonstrating a role for NGF in axon pathfinding and/or axon growth and branching in these targets . Thus, it has been assumed that many or all pelvic noradrenergic neurons are potentially affected by endogenous NGF. However, we found NGF to be the neurotrophic factor least effective at eliciting responses from the pelvic ganglia in embryonic and newborn mice, resulting in a small but significant increase in TH+ cell and fibre outgrowth only in E14.5 mice. An earlier study using Remak's ganglia in chick, which are also derived from the sacral neural crest and are comprised of both sympathetic and parasympathetic neurons – also found a weak response to NGF throughout embryonic development with a limited period (E8–E12) of fibre outgrowth above the control level . This lack of effect of NGF on explants up to P0 in age contrasts with previous studies which showed NGF to stimulate sympathetic neurite outgrowth from dispersed adult rat pelvic ganglion neurons [55, 56, 58]. However, maturation of the pelvic ganglia continues after P0; particularly changes in the pelvic ganglia neurons due to the actions of sex hormones. Thus, it appears that the major actions of NGF occur post-natally.
Neurotrophin-3 (NT-3) is essential during sympathetic neuron development [83–85], but the role of NT-3 in pelvic ganglion development has received only limited attention [49, 82]. We found that NT-3 induces strong sympathetic (TH+) and parasympathetic (non-TH+) fibre outgrowth responses from E14.5 onwards.
Effect of GDNF family ligands on pelvic plexus development
The glial cell line-derived family of neurotrophic factors (GFLs) are implicated in development, maintenance, and plasticity of parasympathetic neurons [43, 86, 87]. Various studies have also implicated GFLs in the development or plasticity of sympathetic noradrenergic neurons [35, 39, 88–90]. In addition, the common GFL co-receptor, Ret, was found to be essential for survival of cholinergic sympathetic neurons in the stellate ganglion , and the development and/or maintenance of cholinergic sympathetic innervation of sweat glands are at least partly dependent on GFRα2 signaling . Thus, the GFLs are likely to play key roles in the development of the pelvic plexus, where noradrenergic sympathetic, cholinergic sympathetic and parasympathetic classes of neurons are all present.
In adult rat pelvic ganglia, GFRα1 has previously been found to be expressed by many noradrenergic and cholinergic neurons ; however, we did not observe detectable GFRα1 immunostaining on TH+ (ie noradrenergic) neurons after E11.5. This may be because GFRα1 is only expressed by TH+ neurons after birth, or due to an interspecies difference. Despite the absence of detectable GFRα1 immunostaining by TH+ cells, we found that GDNF can stimulate outgrowth from both the TH+ and TH- classes of cells. As proposed above for the effects of GDNF-GFRα1 signaling on TH+ cell migration, some GFRα1+/TH- neurites may grow in response to GDNF, and then upregulate TH and downregulate GFRα1 during the culture period. GDNF also induced large increases in parasympathetic fibre outgrowth at E11.5 and E14.5, but had no significant effect on parasympathetic fibre outgrowth at P0. However, neurturin stimulated outgrowth of these fibres at P0, and GFRα2 was upregulated at P0 on the Hu+/TH- cells. The switch from an early importance of GDNF to a later importance for neurturin is fairly common during development of peripheral ganglia [25, 26, 93].
Gfrα2-/- and Nrtn-/- mice have defects in a number of parasympathetic ganglia [87, 93, 94] and the innervation of target organs by the parasympathetic component of the pelvic ganglia has also been shown to be altered. A recent study of P0-P21 Nrtn-/- mice has shown that the parasympathetic fibre deficit in each organ is quite variable and can be due to failure of initial projection to the tissue and/or maintenance of the terminal field . Our results also support a role for neurturin in stimulating parasympathetic (non-TH+) fibre outgrowth, as previously shown in adult rat primary neuronal culture , because we observed significant increases in non-TH+ fibre outgrowth at E11.5, E14.5 and P0. We also observed an effect of neurturin on sympathetic (ie TH+) fibre outgrowth, although this only occurred at E14.5. However, no major deficits have been identified in noradrenergic sympathetic neurons in Gfrα2-/- and Nrtn-/- mice [3, 51, 52], so the in vivo significance of this data is unclear. We found widespread GFRα2 immunostaining on all neurons within the developing pelvic ganglia, which is in contrast to previous studies on adult mice and rat where no GFRα2 expression was found on the noradrenergic sympathetic neurons .
In the adult rat, most noradrenergic neurons, as well as half the penile projecting S1 DRG neurons, contained mRNA for GFRα3 . We could not find detectable levels of GFRα3 protein in pelvic neurons using immunohistochemistry in E11.5 or P0 mice, and levels only barely above background in E14.5 mice. GFRα3 may be upregulated at post-natal stages, especially if it plays a role in the innervation of reproductive tissues, which largely occurs post-natally . Nonetheless, we observed artemin-induced TH+ fibre outgrowth at both E11.5 and P0, but not E14.5. This may be because the number of GFRα3 receptors required to mediate a biological response is below the detection threshold for immunohistochemical detection.
Neurotrophic factor regulation of transmitter phenotype
Neurotrophic factors can be involved in regulating phenotypic characteristics of neurons, including the expression of peptides and enzymes involved in neurotransmitter pathways. Studies in parasympathetic neurons have demonstrated that lack of neurotrophic support can decrease choline acetyltransferase expression and increase neuropeptide Y expression [55, 95]. Of particular relevance to the current study are the effects of neurotrophic factors on TH synthesis: NGF has been found to enhance TH synthesis in adult rat major pelvic ganglion cultures ; neurturin reduced the upregulation of TH expression in cultured pelvic parasympathetic neurons ; and, GDNF has been demonstrated to downregulate expression of TH in dopamine neurons upon overexpression in vivo , but to upregulate the expression of TH in a neuroblastoma cell line by increasing the activity of the TH gene promoter and stabilizing TH mRNA . In the current study we analysed the effects of neurotrophins on the TH+ cell migration and TH+/TH- fibre outgrowth from developing pelvic plexus, but we cannot rule out the possibility that the analysis may be confounded in part due to an action of the factors on the phenotype, as well as migration and neurite outgrowth.
Previous studies have shown that adult pelvic ganglion sympathetic and parasympathetic neurons show differential responses to neurotrophic factors. This study showed that TH+ (sympathetic) neurons are present in the pelvic ganglion primordium from E11.5, and that at this developmental stage, pelvic TH+ neurons already show differences from the non-TH neurons in their neurite outgrowth and migration responses to neurotrophic factors. This may result from the fact that some transcription factors that regulate neurotransmitter expression also regulate expression of receptors for neurotrophic factors. For example, in developing sympathetic ganglia, Phox2b is required for both Ret and TH expression . Further studies are required to determine how expression of the different GFRαs, Trks and p75 are developmentally regulated on cells in pelvic ganglia.
We thank Miles Epstein, Thomas Müller and Louis Reichardt for provision of the Hu, B-FABP and TrkA antibodies respectively, and Annette Bergner and Linda Chuang for excellent technical assistance.
- Keast JR: Unusual autonomic ganglia: connections, chemistry, and plasticity of pelvic ganglia. Int Rev Cytol. 1999, 193: 1-69.View ArticlePubMedGoogle Scholar
- Keast JR: Plasticity of pelvic autonomic ganglia and urogenital innervation. Int Rev Cytol. 2006, 248: 141-208.View ArticlePubMedGoogle Scholar
- Yan H, Keast JR: Neurturin regulates postnatal differentiation of parasympathetic pelvic ganglion neurons, initial axonal projections, and maintenance of terminal fields in male urogenital organs. J Comp Neurol. 2008, 507: 1169-83.View ArticlePubMedGoogle Scholar
- Butler-Manuel SA, Buttery LD, A'Hern RP, Polak JM, Barton DP: Pelvic nerve plexus trauma at radical hysterectomy and simple hysterectomy: the nerve content of the uterine supporting ligaments. Cancer. 2000, 89: 834-41.View ArticlePubMedGoogle Scholar
- Kato T, Murakami G, Yabuki Y: Does the cardinal ligament of the uterus contain a nerve that should be preserved in radical hysterectomy?. Anat Sci Int. 2002, 77: 161-8.View ArticlePubMedGoogle Scholar
- Maas CP, Moriya Y, Steup WH, Klein Kranenbarg E, Velde van de CJ: A prospective study on radical and nerve-preserving surgery for rectal cancer in the Netherlands. Eur J Surg Oncol. 2000, 26: 751-7.View ArticlePubMedGoogle Scholar
- Walsh PC, Donker PJ: Impotence following radical prostatectomy: insight into etiology and prevention. J Urol. 1982, 128: 492-7.PubMedGoogle Scholar
- Purinton PT, Fletcher TF, Bradley WE: Gross and light microscopic features of the pelvic plexus in the rat. Anat Rec. 1973, 175: 697-705.View ArticlePubMedGoogle Scholar
- Wanigasekara Y, Kepper ME, Keast JR: Immunohistochemical characterisation of pelvic autonomic ganglia in male mice. Cell Tissue Res. 2003, 311: 175-85.PubMedGoogle Scholar
- Keast JR: Visualization and immunohistochemical characterization of sympathetic and parasympathetic neurons in the male rat major pelvic ganglion. Neuroscience. 1995, 66: 655-62.View ArticlePubMedGoogle Scholar
- Kapur RP: Colonization of the murine hindgut by sacral crest-derived neural precursors: experimental support for an evolutionarily conserved model. Dev Biol. 2000, 227: 146-155.View ArticlePubMedGoogle Scholar
- Burns AJ, Le Douarin NM: The sacral neural crest contributes neurons and glia to the post-umbilical gut: spatiotemporal analysis of the development of the enteric nervous system. Development. 1998, 125: 4335-47.PubMedGoogle Scholar
- Yntema CL, Hammond WS: Experiments on the origin and development of the sacral autonomic nerves in the chick embryo. J Exp Zool. 1955, 129: 375-413.View ArticleGoogle Scholar
- Le Douarin NM, Kalcheim C: The neural crest. 1999, Cambridge: Cambridge University PressView ArticleGoogle Scholar
- Anderson RB, Stewart AL, Young HM: Phenotypes of neural-crest-derived cells in vagal and sacral pathways. Cell Tissue Res. 2006, 323: 11-25.View ArticlePubMedGoogle Scholar
- Druckenbrod NR, Epstein ML: The pattern of neural crest advance in the cecum and colon. Dev Biol. 2005, 287: 125-33.View ArticlePubMedGoogle Scholar
- Anderson RB, Bergner AJ, Taniguchi M, Fujisawa H, Forrai A, Robb L, Young HM: Effects of different regions of the developing gut on the migration of enteric neural crest-derived cells: a role for Sema3A, but not Sema3F. Dev Biol. 2007, 305: 287-99.View ArticlePubMedGoogle Scholar
- Newgreen D, Young HM: Enteric nervous system: development and developmental disturbances-part 1. Pediatr Dev Pathol. 2002, 5: 224-47.PubMedGoogle Scholar
- Newgreen D, Young HM: Enteric nervous system: development and developmental disturbances – part 2. Pediatr Dev Pathol. 2002, 5: 329-49.View ArticlePubMedGoogle Scholar
- Young HM, Newgreen DF, Burns AJ: Development of the enteric nervous system in relation to Hirschsprung's disease. Embryos, genes and birth defects. Edited by: Ferretti P, Copp A, Tickle C, Moore G. 2004, John Wiley & Sons, 263-300.Google Scholar
- Young HM, Anderson RB, Anderson CR: Guidance cues involved in the development of the peripheral autonomic nervous system. Auton Neurosci. 2004, 112: 1-14.View ArticlePubMedGoogle Scholar
- Francis N, Farinas I, Brennan C, Rivas-Plata K, Backus C, Reichardt L, Landis S: NT-3, like NGF, is required for survival of sympathetic neurons, but not their precursors. Dev Biol. 1999, 210: 411-27.View ArticlePubMedGoogle Scholar
- Ernsberger U: The development of postganglionic sympathetic neurons: coordinating neuronal differentiation and diversification. Auton Neurosci. 2001, 94: 1-13.View ArticlePubMedGoogle Scholar
- Cordes SP: Molecular genetics of cranial nerve development in mouse. Nat Rev Neurosci. 2001, 2: 611-23.View ArticlePubMedGoogle Scholar
- Enomoto H, Heuckeroth RO, Golden JP, Johnson EM, Milbrandt J: Development of cranial parasympathetic ganglia requires sequential actions of GDNF and neurturin. Development. 2000, 127: 4877-89.PubMedGoogle Scholar
- Hashino E, Shero M, Junghans D, Rohrer H, Milbrandt J, Johnson EM: GDNF and neurturin are target-derived factors essential for cranial parasympathetic neuron development. Development. 2001, 128: 3773-82.PubMedGoogle Scholar
- Gallagher D, Gutierrez H, Gavalda N, O'Keeffe G, Hay R, Davies AM: Nuclear factor-kappaB activation via tyrosine phosphorylation of inhibitor kappaB-alpha is crucial for ciliary neurotrophic factor-promoted neurite growth from developing neurons. J Neurosci. 2007, 27: 9664-9.View ArticlePubMed CentralPubMedGoogle Scholar
- Zamburlin P, Gilardino A, Dalmazzo S, Ariano P, Lovisolo D: Temporal dynamics of neurite outgrowth promoted by basic fibroblast growth factor in chick ciliary ganglia. J Neurosci Res. 2006, 84: 505-14.View ArticlePubMedGoogle Scholar
- Abzhanov A, Tzahor E, Lassar AB, Tabin CJ: Dissimilar regulation of cell differentiation in mesencephalic (cranial) and sacral (trunk) neural crest cells in vitro. Development. 2003, 130: 4567-79.View ArticlePubMedGoogle Scholar
- Reichardt LF, Farinas I: Neurotrophic factors and their receptors: roles in neuronal development and function. 1997, Oxford University PressGoogle Scholar
- Ip NY, Stitt TN, Tapley P, Klein R, Glass DJ, Fandl J, Greene LA, Barbacid M, Yancopoulos GD: Similarities and differences in the way neurotrophins interact with the Trk receptors in neuronal and nonneuronal cells. Neuron. 1993, 10: 137-49.View ArticlePubMedGoogle Scholar
- Lin LF, Doherty DH, Lile JD, Bektesh S, Collins F: GDNF: a glial cell line-derived neurotrophic factor for midbrain dopaminergic neurons. Science. 1993, 260: 1130-2.View ArticlePubMedGoogle Scholar
- Henderson CE, Phillips HS, Pollock RA, Davies AM, Lemeulle C, Armanini M, Simmons L, Moffet B, Vandlen RA, Koliatsos VE, Rosenthal A: GDNF: a potent survival factor for motoneurons present in peripheral nerve and muscle. Science. 1994, 266: 1062-4.View ArticlePubMedGoogle Scholar
- Arenas E, Trupp M, Akerud P, Ibanez CF: GDNF prevents degeneration and promotes the phenotype of brain noradrenergic neurons in vivo. Neuron. 1995, 15: 1465-73.View ArticlePubMedGoogle Scholar
- Buj-Bello A, Buchman VL, Horton A, Rosenthal A, Davies AM: GDNF is an age-specific survival factor for sensory and autonomic neurons. Neuron. 1995, 15: 821-8.View ArticlePubMedGoogle Scholar
- Trupp M, Ryden M, Jornvall H, Funakoshi H, Timmusk T, Arenas E, Ibanez CF: Peripheral expression and biological activities of GDNF, a new neurotrophic factor for avian and mammalian peripheral neurons. J Cell Biol. 1995, 130: 137-48.View ArticlePubMedGoogle Scholar
- Hearn CJ, Murphy M, Newgreen D: GDNF and ET-3 differentially modulate the numbers of avian enteric neural crest cells and enteric neurons in vitro. Dev Biol. 1998, 197: 93-105.View ArticlePubMedGoogle Scholar
- Heuckeroth RO, Lampe PA, Johnson EM, Milbrandt J: Neurturin and GDNF promote proliferation and survival of enteric neuron and glial progenitors in vitro. Dev Biol. 1998, 200: 116-29.View ArticlePubMedGoogle Scholar
- Kotzbauer PT, Lampe PA, Heuckeroth RO, Golden JP, Creedon DJ, Johnson EM, Milbrandt J: Neurturin, a relative of glial-cell-line-derived neurotrophic factor. Nature. 1996, 384: 467-70.View ArticlePubMedGoogle Scholar
- Baloh RH, Tansey MG, Lampe PA, Fahrner TJ, Enomoto H, Simburger KS, Leitner ML, Araki T, Johnson EM, Milbrandt J: Artemin, a novel member of the GDNF ligand family, supports peripheral and central neurons and signals through the GFRalpha3-RET receptor complex. Neuron. 1998, 21: 1291-302.View ArticlePubMedGoogle Scholar
- Horger BA, Nishimura MC, Armanini MP, Wang LC, Poulsen KT, Rosenblad C, Kirik D, Moffat B, Simmons L, Johnson E, Milbrandt J, Rosenthal A, Bjorklund A, Vandlen RA, Hynes MA, Phillips HS: Neurturin exerts potent actions on survival and function of midbrain dopaminergic neurons. J Neurosci. 1998, 18: 4929-37.PubMedGoogle Scholar
- Milbrandt J, de Sauvage FJ, Fahrner TJ, Baloh RH, Leitner ML, Tansey MG, Lampe PA, Heuckeroth RO, Kotzbauer PT, Simburger KS, Golden JP, Davies JA, Vejsada R, Kato AC, Hynes M, Sherman D, Nishimura M, Wang LC, Vandlen R, Moffat B, Klein RD, Poulsen K, Gray C, Garces A, Henderson CE, Phillips HS, Johnson EM: Persephin, a novel neurotrophic factor related to GDNF and neurturin. Neuron. 1998, 20: 245-53.View ArticlePubMedGoogle Scholar
- Baloh RH, Enomoto H, Johnson EM, Milbrandt J: The GDNF family ligands and receptors – implications for neural development. Curr Opin Neurobiol. 2000, 10: 103-110.View ArticlePubMedGoogle Scholar
- Paratcha G, Ledda F, Baars L, Coulpier M, Besset V, Anders J, Scott R, Ibanez CF: Released GFRalpha1 potentiates downstream signaling, neuronal survival, and differentiation via a novel mechanism of recruitment of c-Ret to lipid rafts. Neuron. 2001, 29: 171-84.View ArticlePubMedGoogle Scholar
- Mirabella N, Squillacioti C, Paone I, Ciarcia R, Russo M, Paino G: Effects of castration on the expression of brain-derived neurotrophic factor (BDNF) in the vas deferens and male accessory genital glands of the rat. Cell Tissue Res. 2006, 323: 513-22.View ArticlePubMedGoogle Scholar
- Dolatshad NF, Saffrey MJ: Differential expression of glial cell line-derived neurotrophic factor family receptor alpha-2 isoforms in rat urinary bladder and intestine. Neurosci Lett. 2007, 415: 215-8.View ArticlePubMedGoogle Scholar
- Lommatzsch M, Quarcoo D, Schulte-Herbruggen O, Weber H, Virchow JC, Renz H, Braun A: Neurotrophins in murine viscera: a dynamic pattern from birth to adulthood. Int J Dev Neurosci. 2005, 23: 495-500.View ArticlePubMedGoogle Scholar
- Kawakami T, Wakabayashi Y, Aimi Y, Isono T, Okada Y: Developmental expression of glial cell-line derived neurotrophic factor, neurturin, and their receptor mRNA in the rat urinary bladder. Neurourol Urodyn. 2003, 22: 83-8.View ArticlePubMedGoogle Scholar
- Hiltunen JO, Laurikainen A, Klinge E, Saarma M: Neurotrophin-3 is a target-derived neurotrophic factor for penile erection-inducing neurons. Neuroscience. 2005, 133: 51-8.View ArticlePubMedGoogle Scholar
- Laurikainen A, Hiltunen JO, Vanhatalo S, Klinge E, Saarma M: Glial cell line-derived neurotrophic factor is expressed in penis of adult rat and retrogradely transported in penile parasympathetic and sensory nerves. Cell Tissue Res. 2000, 302: 321-9.View ArticlePubMedGoogle Scholar
- Laurikainen A, Hiltunen JO, Thomas-Crusells J, Vanhatalo S, Arumae U, Airaksinen MS, Klinge E, Saarma M: Neurturin is a neurotrophic factor for penile parasympathetic neurons in adult rat. J Neurobiol. 2000, 43: 198-205.View ArticlePubMedGoogle Scholar
- Wanigasekara Y, Airaksinen MS, Heuckeroth RO, Milbrandt J, Keast JR: Neurturin signalling via GFRalpha2 is essential for innervation of glandular but not muscle targets of sacral parasympathetic ganglion neurons. Mol Cell Neurosci. 2004, 25: 288-300.View ArticlePubMedGoogle Scholar
- Wanigasekara Y, Keast JR: Neurturin has multiple neurotrophic effects on adult rat sacral parasympathetic ganglion neurons. Eur J Neurosci. 2005, 22: 595-604.View ArticlePubMedGoogle Scholar
- Keast JR, Kepper ME: Differential regulation of trkA and p75 in noradrenergic pelvic autonomic ganglion cells after deafferentation of their cholinergic neighbours. Eur J Neurosci. 2001, 13: 211-20.PubMedGoogle Scholar
- Meusburger SM, Keast JR: Testosterone and nerve growth factor have distinct but interacting effects on structure and neurotransmitter expression of adult pelvic ganglion cells in vitro. Neuroscience. 2001, 108: 331-40.View ArticlePubMedGoogle Scholar
- Tuttle JB, Steers WD: Nerve growth factor responsiveness of cultured major pelvic ganglion neurons from the adult rat. Brain Res. 1992, 588: 29-40.View ArticlePubMedGoogle Scholar
- Purves-Tyson TD, Arshi MS, Handelsman DJ, Cheng Y, Keast JR: Androgen and estrogen receptor-mediated mechanisms of testosterone action in male rat pelvic autonomic ganglia. Neuroscience. 2007, 148: 92-104.View ArticlePubMed CentralPubMedGoogle Scholar
- Tuttle JB, Mackey T, Steers WD: NGF, bFGF and CNTF increase survival of major pelvic ganglion neurons cultured from the adult rat. Neurosci Lett. 1994, 173: 94-8.View ArticlePubMedGoogle Scholar
- Golden JP, DeMaro JA, Osborne PA, Milbrandt J, Johnson EM: Expression of neurturin, GDNF, and GDNF family-receptor mRNA in the developing and mature mouse. Exp Neurol. 1999, 158: 504-28.View ArticlePubMedGoogle Scholar
- Sawamoto K, Nakao N, Kobayashi K, Matsushita N, Takahashi H, Kakishita K, Yamamoto A, Yoshizaki T, Terashima T, Murakami F, Itakura T, Okano H: Visualization, direct isolation, and transplantation of midbrain dopaminergic neurons. Proc Natl Acad Sci USA. 2001, 98: 6423-8.View ArticlePubMed CentralPubMedGoogle Scholar
- Young HM, Hearn CJ, Farlie PG, Canty AJ, Thomas PQ, Newgreen DF: GDNF is a chemoattractant for enteric neural cells. Dev Biol. 2001, 229: 503-516.View ArticlePubMedGoogle Scholar
- Stewart AL, Young HM, Popoff M, Anderson RB: Effects of pharmacological inhibition of small GTPases on axon extension and migration of enteric neural crest-derived cells. Dev Biol. 2007, 307: 92-104.View ArticlePubMedGoogle Scholar
- Chalazonitis A, Rothman TP, Chen J, Gershon MD: Age-dependent differences in the effects of GDNF and NT-3 on the development of neurons and glia from neural crest-derived precursors immunoselected from the fetal rat gut: expression of GFRalpha-1 in vitro and in vivo. Dev Biol. 1998, 204: 385-406.View ArticlePubMedGoogle Scholar
- Yan H, Bergner AJ, Enomoto H, Milbrandt J, Newgreen DF, Young HM: Neural cells in the esophagus respond to glial cell line-derived neurotrophic factor and neurturin, and are RET-dependent. Dev Biol. 2004, 272: 118-33.View ArticlePubMedGoogle Scholar
- Forrest SL, Keast JR: Expression of receptors for glial cell line-derived neurotrophic factor family ligands in sacral spinal cord reveals separate targets of pelvic afferent fibers. J Comp Neurol. 2008, 506: 989-1002.View ArticlePubMed CentralPubMedGoogle Scholar
- Callahan T, Young HM, Anderson RB, Enomoto H, Anderson CR: Development of satellite glia in mouse sympathetic ganglia: Gdnf and Gfrα1 are not essential. Glia. 2008,Google Scholar
- Clary DO, Weskamp G, Austin LR, Reichardt LF: TrkA cross-linking mimics neuronal responses to nerve growth factor. Mol Biol Cell. 1994, 5: 549-63.View ArticlePubMed CentralPubMedGoogle Scholar
- Chalazonitis A: Neurotrophin-3 in the development of the enteric nervous system. Prog Brain Res. 2004, 146: 243-63.View ArticlePubMedGoogle Scholar
- Britsch S, Goerich DE, Riethmacher D, Peirano RI, Rossner M, Nave KA, Birchmeier C, Wegner M: The transcription factor Sox10 is a key regulator of peripheral glial development. Genes Dev. 2001, 15: 66-78.View ArticlePubMed CentralPubMedGoogle Scholar
- Kurtz A, Zimmer A, Schnutgen F, Bruning G, Spener F, Muller T: The expression pattern of a novel gene encoding brain-fatty acid binding protein correlates with neuronal and glial cell development. Development. 1994, 120: 2637-49.PubMedGoogle Scholar
- Sanicola M, Hession C, Worley D, Carmillo P, Ehrenfels C, Walus L, Robinson S, Jaworski G, Wei H, Tizard R, Whitty A, Pepinsky RB, Cate RL: Glial cell line-derived neurotrophic factor-dependent RET activation can be mediated by two different cell-surface accessory proteins. Proc Natl Acad Sci USA. 1997, 94: 6238-43.View ArticlePubMed CentralPubMedGoogle Scholar
- MacGrogan D, Despres G, Romand R, Dicou E: Expression of the beta-nerve growth factor gene in male sex organs of the mouse, rat, and guinea pig. J Neurosci Res. 1991, 28: 567-73.View ArticlePubMedGoogle Scholar
- Katoh-Semba R, Semba R, Kashiwamata S, Kato K: Sex-dependent and sex-independent distribution of the beta-subunit of nerve growth factor in the central nervous and peripheral tissues of mice. J Neurochem. 1989, 52: 1559-65.View ArticlePubMedGoogle Scholar
- Harper GP, Thoenen H: The distribution of nerve growth factor in the male sex organs of mammals. J Neurochem. 1980, 34: 893-903.View ArticlePubMedGoogle Scholar
- Steers WD, Kolbeck S, Creedon D, Tuttle JB: Nerve growth factor in the urinary bladder of the adult regulates neuronal form and function. J Clin Invest. 1991, 88: 1709-15.View ArticlePubMed CentralPubMedGoogle Scholar
- Varilek GW, Neil GA, Bishop WP, Lin J, Pantazis NJ: Nerve growth factor synthesis by intestinal epithelial cells. Am J Physiol. 1995, 269: G445-52.PubMedGoogle Scholar
- Dalal R, Djakiew D: Molecular characterization of neurotrophin expression and the corresponding tropomyosin receptor kinases (trks) in epithelial and stromal cells of the human prostate. Mol Cell Endocrinol. 1997, 134: 15-22.View ArticlePubMedGoogle Scholar
- Tuttle JB, Steers WD, Albo M, Nataluk E: Neural input regulates tissue NGF and growth of the adult rat urinary bladder. J Auton Nerv Syst. 1994, 49: 147-58.View ArticlePubMedGoogle Scholar
- Huang EJ, Reichardt LF: Neurotrophins: Roles in neuronal development and function. Annu Rev Neurosci. 2001, 24: 677-736.View ArticlePubMed CentralPubMedGoogle Scholar
- Kaplan DR, Miller FD: Neurotrophin signal transduction in the nervous system. Curr Opin Neurobiol. 2000, 10: 381-91.View ArticlePubMedGoogle Scholar
- Glebova NO, Ginty DD: Heterogeneous requirement of NGF for sympathetic target innervation in vivo. J Neurosci. 2004, 24: 743-51.View ArticlePubMedGoogle Scholar
- Hallbook F, Backstrom A, Kullander K, Kylberg A, Williams R, Ebendal T: Neurotrophins and their receptors in chicken neuronal development. Int J Dev Biol. 1995, 39: 855-68.PubMedGoogle Scholar
- Rush RA, Chie E, Liu D, Tafreshi A, Zettler C, Zhou XF: Neurotrophic factors are required by mature sympathetic neurons for survival, transmission and connectivity. Clin Exp Pharmacol Physiol. 1997, 24: 549-55.View ArticlePubMedGoogle Scholar
- Zhou XF, Rush R: Sympathetic neurons in neonatal rats require endogenous neurotrophin-3 for survival. J Neurosci. 1995, 15: 6521-30.PubMedGoogle Scholar
- Francis NJ, Landis SC: Cellular and molecular determinants of sympathetic neuron development. Annu Rev Neurosci. 1999, 22: 541-66.View ArticlePubMedGoogle Scholar
- Airaksinen MS, Saarma M: The gdnf family: signalling, biological functions and therapeutic value. Nat Rev Neurosci. 2002, 3: 383-94.View ArticlePubMedGoogle Scholar
- Rossi J, Tomac A, Saarma M, Airaksinen MS: Distinct roles for GFRalpha1 and GFRalpha2 signalling in different cranial parasympathetic ganglia in vivo. Eur J Neurosci. 2000, 12: 3944-52.View ArticlePubMedGoogle Scholar
- Honma Y, Araki T, Gianino S, Bruce A, Heuckeroth R, Johnson E, Milbrandt J: Artemin is a vascular-derived neurotropic factor for developing sympathetic neurons. Neuron. 2002, 35: 267-82.View ArticlePubMedGoogle Scholar
- Yu LY, Jokitalo E, Sun YF, Mehlen P, Lindholm D, Saarma M, Arumae U: GDNF-deprived sympathetic neurons die via a novel nonmitochondrial pathway. J Cell Biol. 2003, 163: 987-97.View ArticlePubMed CentralPubMedGoogle Scholar
- Enomoto H, Crawford PA, Gorodinsky A, Heuckeroth RO, Johnson EM, Milbrandt J: RET signaling is essential for migration, axonal growth and axon guidance of developing sympathetic neurons. Development. 2001, 128: 3963-74.PubMedGoogle Scholar
- Burau K, Stenull I, Huber K, Misawa H, Berse B, Unsicker K, Ernsberger U: c-ret regulates cholinergic properties in mouse sympathetic neurons: evidence from mutant mice. Eur J Neurosci. 2004, 20: 353-62.View ArticlePubMedGoogle Scholar
- Hiltunen PH, Airaksinen MS: Sympathetic cholinergic target innervation requires GDNF family receptor GFRalpha2. Mol Cell Neurosci. 2004, 26: 450-7.View ArticlePubMedGoogle Scholar
- Heuckeroth RO, Enomoto H, Grider JR, Golden JP, Hanke JA, Jackman A, Molliver DC, Bardgett ME, Snider WD, Johnson EM, Milbrandt J: Gene targeting reveals a critical role for neurturin in the development and maintenance of enteric, sensory, and parasympathetic neurons. Neuron. 1999, 22: 253-63.View ArticlePubMedGoogle Scholar
- Hiltunen JO, Laurikainen A, Airaksinen MS, Saarma M: GDNF family receptors in the embryonic and postnatal rat heart and reduced cholinergic innervation in mice hearts lacking ret or GFRalpha2. Dev Dyn. 2000, 219: 28-39.View ArticlePubMedGoogle Scholar
- Lynch SW, Braas KM, Harakall SA, Kennedy AL, Mawe GM, Parsons RL: Neuropeptide Y (NPY) expression is increased in explanted guinea pig parasympathetic cardiac ganglia neurons. Brain Res. 1999, 827: 70-8.View ArticlePubMedGoogle Scholar
- Georgievska B, Kirik D, Bjorklund A: Overexpression of glial cell line-derived neurotrophic factor using a lentiviral vector induces time- and dose-dependent downregulation of tyrosine hydroxylase in the intact nigrostriatal dopamine system. J Neurosci. 2004, 24: 6437-45.View ArticlePubMedGoogle Scholar
- Xiao H, Hirata Y, Isobe K, Kiuchi K: Glial cell line-derived neurotrophic factor up-regulates the expression of tyrosine hydroxylase gene in human neuroblastoma cell lines. J Neurochem. 2002, 82: 801-8.View ArticlePubMedGoogle Scholar
- Pattyn A, Morin X, Cremer H, Goridis C, Brunet JF: The homeobox gene Phox2b is essential for the development of autonomic neural crest derivatives. Nature. 1999, 399: 366-70.View ArticlePubMedGoogle Scholar
- Fairman CL, Clagett-Dame M, Lennon VA, Epstein ML: Appearance of neurons in the developing chick gut. Dev Dyn. 1995, 204: 192-201.View ArticlePubMedGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.