Papers by Donald Newgreen
Chicken wings and the brachial plexus
Neurological Research, 2007
Some stages of limb development can now be described in terms of gene sequences and functions. Th... more Some stages of limb development can now be described in terms of gene sequences and functions. This paper reports on the development of the brachial plexus (BP) in the chick. It also presents a short review on the principles of the peripheral nerve outgrowth. The early development of the brachial plexus of chicken embryos is mapped using immunohistochemistry. This is then analysed in relation to the expression pattern of an axonal guidance gene, Semaphorin3a, by in situ hybridization studies. The motor axons that innervate the chick wing emerge from the spinal cord in spinal nerves 12-17. These axons grow towards the developing limb and then congregate at its base to form the plexus. In response to unknown cues, these axons rearrange, before emerging in the defined nerve trunks that innervate the limb. The developmental stages of BP morphogenesis described here closely correlate with previous reports with a significant difference of a shorter 'waiting period'. The development of the brachial plexus is now better understood. The waiting period, with more modern techniques, is observed to be shorter than previously reported. The significance of this and the role of the guidance molecule, Semaphorin3a, in this process, are being investigated and the results may have important implications on the management of brachial plexus palsy and other peripheral nerve lesions.
In Vitro Cellular & Developmental Biology - Animal, 2006
IS-002 Effects of age, presence of neurons and endothelin-3 on the ability of neural crest cells to colonize recipient gut(International Session I,Better Life for Sick Children, Better Future for Pediatric Surgery,the 45th Annual Meeting of Japanese Society of Pediatric Surgeons)
日本小児外科学会雑誌, May 20, 2008
The Neural Crest
Molecular Biology Intelligence Unit, 2005
ABSTRACT The concept of the epithelial-mesenchymal transition (EMT) arose from developmental biol... more ABSTRACT The concept of the epithelial-mesenchymal transition (EMT) arose from developmental biology, (see ref. 1) where EMT occurs in many situations, each being predictable, stereotyped and with the outcomes often dramatic. The EMT of the neural crest (NC) is an example of this event in development. In its own right; the NC has been ranked as a “fourth germ layer” by Hall.[2] The tissues and structures to which the NC gives rise is widespread in the body and diverse in cell types, ranging from craniofacial connective tissues to peripheral nerve and glial cells to skin pigment cells.[3] In addition, abnormalities involving NC development seem to be disproportionately represented in human birth defects. The NC is important for evolutionary research too, because it is the only organ system unique to vertebrates. Its appearance in evolution is suggested to have enabled the massive adaptive radiation of these chordates. Technically, the experimental approaches for developmental biology, described as “cutting, labeling and pasting”,[4] have shown the NC to be a particularly accessible, manipulatable and robust subject, with relatively straight-forward evaluation of the results in terms of altered developmental patterns. Thus because of its importance and technical advantages, the NC is probably the most studied developmental EMT.
Pediatric Surgery International, 2015
Dr. Hadziselimovic reminds us that in evolution, the primary structure that descended is the caud... more Dr. Hadziselimovic reminds us that in evolution, the primary structure that descended is the caudal epididymis, and the testis appears to have descended secondarily. However, in the human, clearly descent of the testis is a major process occurring simultaneously with descent of the epididymis.
Catecholamine accumulation in neural crest cells and the primary sympathetic chain
The American journal of anatomy, 1977
Catecholamine accumulation in chick embryos of stages 16 to 24 was investigated using formaldehyd... more Catecholamine accumulation in chick embryos of stages 16 to 24 was investigated using formaldehyde-induced fluorescence. Fluorescence first appeared at stage 21 in the anterior sympathetic chain. After L-DOPA treatment, this fluorescence appeared at stage 18. Noradrenaline could not advance the onset of fluorescence or reconstitute fluorescence after its depletion by reserpine at stages 22 to 24. Under no conditions could fluorescence be identified in neural crest cells prior to their aggregation to form the primary sympathetic chain. Noradrenaline induced fluorescence in the neural tube, notochord, myotome, sclerotome, gut mesenchyme and suprarenal cortical cells. In addition to these structures, the dorsal pancreas and some blood cells were fluorescent after l-DOPA treatment. The implication of the results for the neural crest origin of APUD (Amine Precursor Uptake Decaboxylase) cells is considered.
The rostral level of origin of sympathetic neurons in the chick embryo, studied in tissue culture
The American journal of anatomy, 1979
Groups of three consecutive somites from the first to the eleventh somite from chick embryos of s... more Groups of three consecutive somites from the first to the eleventh somite from chick embryos of stages 17-18 were grown in tissue culture for seven days. Sympathetic neurons, identified both by phase contrast microscopy and FIF histochemistry, occurred only in cultures which included the sixth, or more caudal, somites. If it is assumed that sympathetic precursor cells (neural crest cells) have not undergone a caudal shift prior to stages 17-18, and taking into account the loss of one or two rostral somites, then the anterior sympathetic ganglia are derived from neural crest caudal to the sixth or seventh somite. Thus, the vagal zone (level with somites 1-7) contributes little to the sympathetic nervous system.
Neural crest cell outgrowth cultures and the analysis of cell migration
Methods in molecular biology (Clifton, N.J.), 2000
ABSTRACT The neural crest gives rise to many differentiated cell types including craniofacial con... more ABSTRACT The neural crest gives rise to many differentiated cell types including craniofacial connective tissue, peripheral neurons, Schwann cells, various endocrine organs, and pigment cells and it has been extensively studied as a model of cell commitment and lineage diversification (1). However, one of its major features is its suitability as a model for studying morphogenesis (2). It is an excellent example of epitheliumtomesenchyme transition and cell migration, because in the neural crest these events a. are strictly timetabled and routed, b. are of large scale, c. are easy to focus on because they occur when the rest of the body-plan has stabilized, d. are relatively accessible to manipulation, and e. can be replicated with high fidelity in cell culture.
The migration of neural crest cells
International review of cytology, 1986
Development (Cambridge, England), 1988
Differentiation in vitro of sympathetic cells from chick embryo sensory ganglia
Journal of embryology and experimental morphology, 1975
This study was carried out in order to determine what factors control the differentiation of cert... more This study was carried out in order to determine what factors control the differentiation of certain neural crest cells in the chick embryo. Emphasis was placed on the morphologically and biochemically divergent sensory and sympathetic pathways of differentiation. Embryos were precisely stage according to Hamburger & Hamilton (1951) and it was observed that sensory ganglia with somites, explanted at stages 21-24, gave rise to cells showing formaldehyde-induced fluorescence in more than 25% of explants. These cells were identical in properties to the fluorescent cells of the sympathetic system of embryos of similar age, and appeared by 12 days in vitro. These fluorescent cells did not appear when somites and sensory ganglia explants were maintained separately. The incidence of fluorescent cells in combined explants was considerably reduced or absent when cultures were maintained for 7 days or less, or when the explants were obtained from stage 25-26 embryos. Furthermore, when neural ...
Journal of Pediatric Surgery, 2011
Background/Purpose: Inguinoscrotal testicular descent is controlled by androgens between embryoni... more Background/Purpose: Inguinoscrotal testicular descent is controlled by androgens between embryonic days E16-19, but androgen receptor (AR) and estrogen receptor (ER) locations are unknown. We aimed to find AR, ERα, and ERβ in the gubernaculum and inguinal fat pad (IFP) in normal rats and after flutamide treatment. Methods: Sprague-Dawley timed-mated rats were injected with flutamide (75 mg/kg body weight/5% ethanol + oil) on E16-19 or vehicle alone. Male fetuses or pups (5-10/group) were collected at E16; E19; and postnatal (P) days 0, 2, 4, 8. Sections were prepared for hematoxylin and eosin or immunohistochemistry for AR, ERα, and ERβ. Receptor labeling was quantitated as distinct nuclear labeling/100 μm 2 in gubernaculum and IFP. Results: There was minimal gubernacular AR-labeling until E19, dramatically increasing postnatally. By contrast, at E16-E19 there was significant IFP AR immunoreactivity suppressed by flutamide (P b .05). No ERα expression was observed, but ERβ was expressed in both gubernaculum and IFP, maximally at E16, but unchanged by flutamide. Conclusions: During the androgen sensitivity window (E16-19), the gubernaculum contains ERβ but minimal ERα or AR, while the IFP, which is supplied by the genitofemoral nerve, contains abundant AR that are flutamide-sensitive. These results suggest that the IFP could be the site of androgenic action controlling gubernacular development.
European Journal of Cardio-Thoracic Surgery, 2008
Differences in extra-cellular matrix and myocyte homeostasis between the neonatal right ventricle... more Differences in extra-cellular matrix and myocyte homeostasis between the neonatal right ventricle in hypoplastic left heart syndrome and truncus arteriosus §
Physical influences on neural crest cell migration in avian embryos: Contact guidance and spatial restriction
Developmental Biology, 1989
Several ideas on how neural crest (NC) cell migration in bird embryos might be dependent on the p... more Several ideas on how neural crest (NC) cell migration in bird embryos might be dependent on the physical qualities of the internal embryonic environment were studied. Contact guidance has been suggested to direct NC cells ventrally in the trunk, but this has been subject to doubt (see Newgreen and Erickson, 1986, Int. Rev. Cytol. 103, 118-119). On reexamination, in situ extracellular matrix (ECM) and cell processes on the medial face of the somites were found appropriately oriented for this function. In addition, tissue culture models of oriented ECM could induce orientation of NC cells which mimicked that observed in the embryo. It is concluded that in this situation, oriented structures contribute to directed migration of NC cells in vivo, but the mechanism of contact guidance (i.e., steric or adhesive guidance) could not be ascertained. Contact guidance, in the form of steric guidance, has also been suggested as limiting ventrad NC cell movement at the midbrain level due to an insurmountable ridge on the side of the midbrain. The presence of this ridge was confirmed but it is unlikely to be responsible for prevention of ventrad migration, because, although it subsides very rapidly, the cells still refuse to move ventrad, and because models of this ridge in vitro proved to be no obstacle to NC cells. NC cell migration is also described as being limited by gross space between other organs or tissues. In vitro, NC cells could penetrate Nucleopore filters with pore diameters of 0.86 micron or greater. Observation of cell-free spaces in embryos showed that these were almost all much larger than the minimum pore size established experimentally. It is therefore concluded that in general the dimensions of gross tissue spaces probably do not set important limits for NC cell migration, but that the dimensions of transiently distensible microspaces between ECM fibrils may be a critical physical parameter.
Developmental Biology, 1983
The neural retina of avian embryos was spread on a membrane filter and cut in any desired orienta... more The neural retina of avian embryos was spread on a membrane filter and cut in any desired orientation.
Spatiotemporal changes in HNK-1/L2 glycoconjugates on avian embryo somite and neural crest cells
Developmental Biology, 1990
Neural crest cell migration was studied in trunks of quail and chick embryos using HNK-1 and L2 a... more Neural crest cell migration was studied in trunks of quail and chick embryos using HNK-1 and L2 antibodies. At the intersegmental cleft, labeled crest cells were associated with the rostral wall of the somite rather than blood vessels. Migration into and through the rostral part of the sclerotomes was more rapid (40-70 microns/hr; quail) and the onset of localization was earlier (after 13-16 hr; quail) than previously supposed. Crest cells here were initially mono- to multipolar, scattered, and inconsistently oriented and formed numerous close (about 20 nm) homo- and heterotypic cell-cell contacts. In vitro models suggested that significant numbers of crest cells, however, could be unlabeled at this early phase. Somitic properties covarying with the hemisegmental pattern of crest cell immigration were investigated. Laminin distribution, although asymmetric in the somites, was not closely related to that of crest cells. Tenascin distribution matched that of crest cells, but only at the localization stage. Earlier, maximal tenascin expression occurred in the somite's caudal wall, a region avoided by crest cells. Chondroitin 6-sulfate proteoglycan expression was elevated in the caudal somite-half at the localization phase and also, at lumbar levels, at the immigration stage. This is consistent with tenascin and proteoglycan having a negative role in crest cell migration. The rostral somite-half was also labeled by HNK-1 and L2, but only in quails. This was associated with the cell surface, was transient, was stable to mild proteolysis, and was labile to cryoprocessing and lipophilic solvents. The spatial and temporal congruence with crest migration suggests that the HNK/L2 adhesion-related carbohydrate epitope on the somites indicates a molecule (possibly glycolipid) which acts via heterotypic cell-cell contacts to provide one cue in the patterned distribution of crest cells in the somites.
Developmental Biology, 1995
Developmental Biology, 2002
Peripheral nerve and vascular patterns are congruent in the adult vertebrate, but this has been d... more Peripheral nerve and vascular patterns are congruent in the adult vertebrate, but this has been disputed in vertebrate embryos. The most detailed of these studies have used the avian forelimb as a model system, yet neurovascular anatomical relationships and critical vascular remodeling events remain inadequately characterized in this model. To address this, we have used a combination of intravascular marker injection, multilabel fluorescent stereomicroscopy, and confocal microscopy to analyze the spatiotemporal relationships between peripheral nerves and blood vessels in the forelimb of 818 quail embryos from E2 (HH13) to E15 (HH41). We find that the neurovascular anatomical relationships established during development are highly stereotypic and congruent. Blood vessels typically arise before their corresponding nerves, but there are several critical exceptions to this rule. The vascular pattern is extensively remodeled from the earliest stage examined (E2; HH13), whereas the peripheral nerves, the first of which enter the forelimb at E3.5-E4 , have a progressively unfolding pattern that, once formed, remains essentially unchanged. The adult neurovascular pattern is not established until E8 (HH34). Peripheral nerves are always found to track close and parallel to the vasculature. As they track distally, peripheral nerves always lie on the side of the vasculature away from the center of the forelimb. Neurovascular patterns have a hierarchy of congruence that is highest in the dorsoventral plane, followed by the anteroposterior, and lastly the proximodistal planes. © 2002 Elsevier Science (USA)
A procedure for the rapid freezing of whole embryos
Experientia, 1977
A procedure for the rapid freezing of whole chick embryos for histochemical treatment is describe... more A procedure for the rapid freezing of whole chick embryos for histochemical treatment is described. The problems of deformation during preparation for quenching and orientation for sectioning have been largely overcome by placing embryos inside lengths of chicken trachea. The subsequent disorientation of tissues that follows cracking and shattering due to the rapid freezing of whole embryos is avoided. The method permitted a more precise identification of the position and time of appearance of formaldehyde-induced fluorescence and myosin antibody immunofluorescence in serially sectioned embryos.
Uploads
Papers by Donald Newgreen