bluuebunny/crossref_metadata_2025_split huggingface dataset:
Substance P‐like immunoreactivity in developing cranial parasympathetic neurons of the rat
Authors: Ayer‐LeLievre Christiane , Seiger ÅKe 
Published: April 2003

AbstractSubstance P‐like immunoreactivity (SPLI) has been observed in cell bodies of fetal cranial parasympathetic ganglia of rat. It first appears at day 16 of gestation at the same time as in cranial sensory ganglia. From day 17 to 21, SPLI neurons constitute most, if not all, submandibular‐sublingual and intralingual ganglia, they form 30–40% of otic and pterygopalatine ganglia and numerous such neurons are found in the myenteric plexus of the esophagus as well as in pharyngeal and buccal walls. The immunoreactive material is thinly granular, and its appearance does not change with prenatal development. The immunoreactivity in cell bodies of parasympathetic ganglia decreases at the end of the gestational period, and cannot be evidenced any more in most cells of normal adult ganglia. However, the corresponding SPLI fibers remain intensely immunoreactive. When grafted to rat irides, which have been chemically depleted of intrinsic SPLI fibers, submandibular, otic and pterygopalatine ganglia from pre‐ or postnatal rats rapidly produce a large amount of SPLI fibers on the iris mimicking the pattern of sensory innervation. This proves the presence of SPLI neurons in adult parasympathetic ganglia, at least in experimental conditions.This study of fetuses and grafts demonstrates the existence of neurons in SPLI parasympathetic cranial ganglia which has been underestimated or ignored previously as a result of observations on adult ganglia. The very large proportion of SPLI neurons in the ganglia of the salivary gland might be of importance for the interpretation of experimental studies on the control of salivation. The presence of SPLI in all three types of peripheral ganglia, sensory, sympathetic and parasympathetic, raises the question of its functional significance in the different compartments of the peripheral nervous system.
Effect of glucocorticoids on development of the membrane resting potential of chick embryo brain cells in culture
Authors: Romano Marta C. , Velázquez P.N. , Nún̄ez M. Bonilla , Fuentes‐Pardo Beatriz 
Published: April 2003

AbstractProgressive increase in membrane resting potential (MRP) values in cultured chick embryo brain neurons were recorded from days 2 to 10 of development. Application of corticosterone or prednisone in 24 hr old cultured cells caused a significant increment in MRP recorded at day 2 of culture with respect to control. When ouabain was added to the corticosterone treated cells its effect on the MRP was impaired. An increment in protein synthesis and a reduction in sodium concentration were also observed in corticosterone pretreated cells. These results show that corticoids accelerate the differentiation process in cultured cells particularly the MRP, stimulating perhaps the Na+‐K+ ATPase pump.
Regional [3H]acetylcholine and [3H]nicotine binding in developing mouse brain
Authors: Larsson Christer , Nordberg Agneta , Falkeborn Ylva , Lundberg Per‐Åke 
Published: April 2003

AbstractThe postnatal development of nicotine‐like binding sites in the cortex, hippocampus, midbrain and cerebellum of 3‐, 7‐, 12‐, 17‐ and 30‐day‐old mice was studied. Two different nicotinic cholinergic ligands, namely [3H]acetylcholine ([3H]ACh) and [3H]nicotine ([3H]NIC) were used to detect the nicotine‐like binding sites in in vitro binding assays. The postnatal development of the binding sites of [3H]NIC increased gradually with age in all brain regions studied. The [3H]ACh binding, on the other hand, showed a marked peak on day 12 in the cerebellum and midbrain but did not change notably with age in the hippocampus and cortex, except for a slight temporary increase in the cortex on day 7. The time‐course for the appearance of nicotinic binding sites as observed with [3H]ACh was found to be rather similar to that earlier described for [3H]alpha‐bungarotoxin binding sites, whereas that for [3H]NIC differed from that described for other nicotinic ligands.
The effect of exogenous gangliosides on neurons in culture: A morphometric analysis
Authors: Massarelli R. , Ferret B. , Gorio A. , Durand M. , Dreyfus H. 
Published: April 2003

AbstractCultures of isolated neurons have been treated with a purified preparation of gangliosides (10−5M and 10−9M) added to the cell growth medium at the 3rd day in culture and a morphometric analysis of the cells was performed with an image analyzer after 1 and 4 days of treatment. The number of cells and the area of the cell bodies were increased following the treatment. The results indicate as well the ‘sprouting’ effect of the glycolipids on the number of secondary neuronal processes and an increase in the length of the primary neuntes. The present data and other biochemical evidence (Dreyfus et al., 1984, J. Neurosci. Res.) suggest that the addition of exogenous gangliosides may have a trophic effect on neurons, greatly enhances the number of cell to cell contacts, and, possibly, stimulates cell proliferation and differentiation.
Pheochromocytoma PC12 cells influence the differentiation of co‐cultured skeletal myotubes
Authors: Defez Roberto , Brachet Philippe 
Published: April 2003

AbstractRat skeletal myotubes were cultured in the presence or absence of pheochromocytoma PC12 cells under experimental conditions permitting the maintenance of the muscle cells for up to 5 weeks. The number of acetylcholine receptors (AChRs), estimated using radioiodinated α‐bungarotoxin (α‐BTX), was comparable in both types of culture for the first 2 weeks. After prolonged incubation (4 weeks), however, α‐BTX binding sites were two times more abundant in the PC12‐myotube cultures than in the myotube cultures. This is likely to reflect a higher number of AChRs at the surface of the myotubes, for control experiments showed that the contribution of PC12 cells was negligible. Presence of PC12 cells also increased the number of AChR aggregates. Use of fluorescent α‐BTX demonstrated that mixed cultures contained two times more receptor patches than did myotubes alone during the first 2 weeks of culture, and up to five times more after 4 weeks. Essentially all the tight contacts established between PC12 cells and myotubes were characterized by a receptor cluster and, in some cases, by an aggregate of an acetylcholine esterase (AChE), as visualized by immunohistochemistry. Furthermore an antiserum specific for the adult (fast) isoform of the myosin heavy chain stained some myotubes in longterm, mixed cultures. The antigen was never observed in sister cultures of myotubes alone. These data show that PC12 cells, which are thought to derive from the medullary part of the adrenal gland, can influence the differentiation of skeletal muscle cells in several ways.
Multiple forms of aryl acylamidase in regional tissues of developing rat brain
Authors: Hsu Louise L. 
Published: April 2003

AbstractThe specific activities of two forms of aryl acylamidase (AAA) were examined in 7 regions of the developing rat brain, plus the remainder of the brain and the whole brain. AAA‐1 activity peaked at 15 days old in all brain regions studied except the whole brain where it peaked at 22 days of age. AAA‐2 activity peaked between 15 and 29 days old in most brain regions studied except corpus striatum and hippocampus where the AAA‐2 activity peaked before 15 days old. In all areas and at all time periods, with the exception of CS after 15 days of age, AAA‐2 activity was much higher than that of AAA‐1. The developmental pattern of AAA‐1 is generally the same in the different brain regions while that of AAA‐2 shows more regional specificity. These results indicate that neither AAA‐1 nor AAA‐2 may be associated with amine N‐acetyltransferase in the brain which has an entirely different developmental pattern.
The binding properties and regional ontogeny for [3H]glutamic acid Na+‐independent and [3H]kainic acid binding sites in chick brain
Authors: Voukelatou G. , Angelatoy F. , Kouvelas E.D. 
Published: April 2003

AbstractThe binding kinetics, pharmacological properties and regional ontogeny of l‐[3H]glutamic acid Na+‐independent and [3H]kainic acid binding sites were studied in preparations of chick brain. One binding component was found for l‐[3H]glutamic acid with a Kd value of 176 × 10 9M. For [3H]kainic acid two binding components were found in the hemispheres, optic lobes and brain stem, one with high affinity and a Kd value of 12.5 × 10 9M and one with low affinity and a Kd value of 260 × 10 9M. In cerebellum only one binding site was detected for [3H]kainic acid with a Kd value of 144 × 10 9M. The ontogeny of l‐[3H]glutamic acid and [3H]kainic acid binding sites was studied using membrane preparations (48,000 g pellet) of hemispheres, optic lobes, brain stem and cerebellum. Binding of l‐[3H]glutamic acid was already significant in all brain regions by embryonic day 11 but major increases in total receptor number per brain region or per mg of protein were apparent by embryonic day 19 and especially after hatching. Cerebral hemispheres, optic lobes and brain stem showed few [3H]kainic acid binding sites by day 13 in ovo. An increase follows which, in hemispheres and optic lobes, continues at the same rate during the first two weeks after hatching. In cerebellum, by contrast, the kainic acid binding site is almost undetectable until embryonic day 15. The appearance of these binding sites in cerebellum takes place during the restricted period between days 15 in ovo and 5 post‐hatching. This pattern of development of [3H]kainic acid binding sites almost parallels the developmental patterns of the molecular layer of chick cerebellum and it is consistent with the results of our autoradiographic study showing that the great majority of kainic acid binding sites are localized in the molecular layer.
Fetal ethanol exposure: A morphometric analysis of myelination in the optic nerve
Authors: Samorajski T. , Lancaster F. , Wiggins R. C. 
Published: April 2003

AbstractPregnant Long‐Evans rats were fed a liquid diet containing ethanol during gestation. Controls consisted of both pair‐fed dams and dams fed ad libitum with an equivalent, iso‐caloric diet lacking ethanol. Subsequent effects of ethanol measured in the offspring include a significant lag in the rate at which non‐myelinated axons are lost in association with the initial overproduction of neurons. Additionally, there was a slight lag in the rate of acquisition of myelinated axons; and altogether there was a large increase in the ratio of non‐myelinated to myelinated axons. Frequency spectra of myelinated and non‐myelinated axons by size were normal, and the relationship between axon size and myelin lamellae was also normal. Measured against the dynamic, normal background of rapid cell‐loss and the progressive development of myelin, morphometric demonstration and evaluation of the comparatively small divergences associated with fetal alcohol exposure are difficult; nevertheless, these results are consistent with and help account for the marginal hypomyelination previously observed by quantitative neurochemistry.
Polyamines affect growth of cultured rat cerebellar neurons in different sera
Authors: Gilad Gad M. , Gilad Varda H. 
Published: April 2003

AbstractThe study examines the effects of polyamines on growth of cultured neurons from 6‐day‐old rat cerebellar cortex, by means of: (a) irreversible inhibition of ornithine decarboxylase activity with α‐difluoromethylornithine, and (b) treatment with the exogenous diamine putrescine and the polyamines spermidine and spermine, in the presence of sera from different sources. Inhibition of ornithine decarboxylase activity starting at plating time led after 24 hr to a partial inhibition of cell aggregation with a drastic (90%) inhibition of neurite formation. However, after 48 hr of enzyme inhibition aggregation and neurite formation increased to approach the 24 hr control values and eventually cultures fully recovered. Polyamines added at plating time in the presence of fetal calf serum led to a permanent dose‐dependent inhibition of aggregation and neurite formation, spermine being effective at lower doses (spermine < spermidine ⪡ putrescine). Adhesion of cells to polylysine coated surfaces was not affected by polyamines. Recovery from the cytostatic polyamine effect was observed after washing and addition of fresh medium. Prevention of the effect was achieved in the presence of aminoguanidine, an inhibitor of diamine and polyamine oxidases. The preventive effect of aminoguanidine was dose polyamine‐dependent, with higher aminoguanidine concentrations needed to prevent the spermine effect (spermine > spermidine > putrescine). The polyamine effects were observed in the presence of fetal calf, heat‐inactivated fetal calf and human sera, but not with rat serum. Addition of polyamines to 24‐hr‐old cultured neurons, in the presence of fetal calf serum, led 12 hr later to cell death. This lethal effect could be inhibited by aminoguanidine. We conclude: (a) irreversible inhibition of ornithine decarboxylase activity delays but does not prevent neuronal growth in culture; (b) oxidation products of extracellular polyamines inhibit cell aggregation and neurite formation of cultured neuroblasts, and have lethal effects on growing neurons in culture, and (c) different pharmacological effects of polyamines can be expected in different species.
Histochemical distribution of acid glycosaminoglycans in rat cerebellum during postnatal development: Neuropile
Authors: Alvarado M.V. , Castejon H.V. 
Published: April 2003

AbstractDevelopmentally regulated modifications of glycosaminoglycans (GAGs) in the central nervous system (CNS) have suggested that also in the CNS, these compounds might participate in morphogenesis and nerve cell differentiation. However very few studies have been reported concerning the regional distribution of these compounds by histochemical techniques. We have used the Alcian Blue staining method also in conjunction with enzymatic digestion and with a technique which allowed the measurement of the degree of GAG sulphatation. The combination of the three techniques showed that during the first week GAGs, presumed to be hyaluronic acid, are localized throughout the neuropile of the entire cerebellum and especially in the medullary region. Sulphated glycans appear later in the medullary region (particularly at the border between the medullary region and the internal granular layer) and in all the layers of cerebellum (in particular around the Purkinje and deep cerebellar nuclei neurons and possibly in the cerebellar glomeruli). Sulphated glycans in the medullary region disappear around the 12th day when myelination starts. The transient presence of glycoproteins in the molecular layer was also detected.
Benzodiazepine and muscarinic cholinergic binding sites in striatum and brainstem of the human fetus
Authors: Schlumpf M. , Lichtensteiger W. 
Published: April 2003

AbstractThe regional distribution of binding sites for [3H]flunitrazepam and [3H]N‐methyl‐scopolamine was studied in human fetal brain of 18 and 23 weeks gestation by in vitro autoradiography. Areas densely labelled by both ligands include the hypoglossal nucleus and the striatum. The latter is characterized by a patchy distribution of both binding sites reminiscent of acetylcholinesterase staining. Similarities with the rat fetus and the occurrence of binding sites in areas of potential significance for fetal behaviour are discussed.
Procedure for establishing oligodendroglial cells in primary cultures based on developmental parameters
Authors: Juurlink B. H. J. , Devon R. M. 
Published: April 2003

AbstractWe have established cultures using dissociated cells obtained from the neopallium of mouse pups at several different stages of development. The cellular composition of these cultures changed from more than 95% astrocytes when cultures were established from the neopallium of neonates to more than 90% oligodendrocytes when cultures were established from the neopallium of 2‐week‐old pups. The oligodendrocytic nature of the cells was established on morphological bases as well as the presence of an oligodendrocytic marker, galactocerebroside.
Dysmyelinogenesis in caprine β‐mannosidosis: Ultrastructural and morphometric studies in fetal optic nerve
Authors: Lovell Kathryn L. , Boyer Philip J. 
Published: April 2003

AbstractThe optic nerves from a goat fetus affected with β‐mannosidosis and a control fetus were analysed morphologically in order to investigate developmental aspects of β‐mannosidosis‐associated myelin deficits. In the affected fetus, the number of myelinated axons per unit area was about 25% of the control values. Histograms of axonal diameter indicated that a greater percentage of the myelinated and unmyelinated axons were of larger caliber in the affected fetus than in the control fetus and that very few small axons were myelinated in the affected animal. The mean values of myelin sheath thickness in the affected and control animals did not differ significantly. Ultrastructural analysis revealed a decreased proportion of oligodendrocytes and an increased proportion of astrocytes in the affected fetus.These results indicate that the pathogenetic process leading to cellular abnormalities and myelin deficits in β‐mannosidosis has been initiated prior to 124 days gestation, during an early stage of myelination in the goat optic nerve. The decrease in number of oligodendrocytes suggests that early cell death and/or change in oligodendrocyte proliferation contribute to the myelin deficit. Analysis of the prenatal development of lesions will help clarify the pathogenesis of dysmyelinogenesis in β‐mannosidosis.
Catalase protection of neuronal survival in vitro is not directed to the accumulation of peroxides in the culture medium
Authors: Martin Estralita M. E. , Skaper Stephen D. , Varon Silvio 
Published: April 2003

AbstractWalicke et al. (1986, J. Neurosci. 6, 1114–1121) have shown that catalase can replace the pyruvate requirement for survival of CNS neurons cultured in vitro. Since presently the only known function of catalase is the enzymatic degradation of hydrogen peroxide to water and oxygen, the simplest interpretation of the ability of catalase to support neuronal survival would be that catalase removes from the culture medium hydrogen peroxide. To test this hypothesis 8‐day embryonic chick forebrain cells were cultured for 24 hr in a modified Eagle's Basal Medium with the serum‐free supplement N1 (HEBM/N1) in the presence or absence of Phenol Red, 20 μg/ml catalase, 1 mM pyruvate, and/or 25 mM N‐2‐hydroxyethylpiperazine‐N′‐2‐ethane‐sulfonic acid (HEPES) on a polyornithinelaminin substratum. The various media were then assayed for peroxide content using the potassium iodide method described by Wang and Nixon (1978, In Vitro14, 714–722). The present data reveal that (1) HEBM/N1 normally contains approximately 50 μM peroxides, little of which is hydrogen peroxide, (2) the organic peroxide levels accumulating in this medium are not reduced by either catalase or pyruvate, and (3) medium modifications can reduce to no longer detectable levels the peroxides accumulating in the medium, but catalase or pyruvate is still required for neuronal survival. We conclude that catalase must exert its survival‐promoting action at levels other than peroxides accumulating in the culture medium.
Axonal maturation in development—II. Immunofluorescence study of rat spinal cord and cerebellum with axon‐specific neurofilament antibodies
Authors: Bignami A. , Dahl D. 
Published: April 2003

AbstractNeurofilament monoclonal antibodies derived from mice immunized with chicken brain antigen or purified bovine NF 150K and NF 200K either stained only axons or they stained neuronal perikarya, dendrites and axons. Antibodies in the second group were called conventional because they decorated tissue sections like the neurofibrillary methods of traditional histology. Axon‐specific anti‐bodies either reacted with phosphorylated epitopes or they were phosphate/phosphatase insensitive thus suggesting reactivity with post‐translational modifications other than phosphorylation. Another possibility was reactivity with phosphorylated epitopes inaccessible to exogenous phosphatases. Conventional neurofilament antibodies stained motor and sensory neurons in day 12 and day 13 rat embryos, respectively, as previously reported with neurofilament antisera. Immunoreactivity with axon‐specific antibodies first appeared in motor and sensory axons at different times in development: day 13–14 (3 monoclonals); day 17 (6 monoclonals); day 21 (1 monoclonal); postnatal day 2(1 monoclonal). There were no major differences between conventional and axon‐specific antibodies as to the time of appearance of Purkinje cell baskets in postnatal rat cerebellum. With two exceptions all monoclonals first stained thin baskets on day 11. Immunoreactivity of Purkinje cell baskets with two monoclonals reacting with phosphorylated NF 200K first appeared on days 14 and 20. It is suggested that post‐translational modifications may stabilize the neurofilaments, thus accounting for their late appearance by electron microscopy in development.
The trophic responses of avian sensory ganglia in vitro to N‐acetylated and des‐acetyl forms of α‐melanocyte stimulating hormone (α‐MSH) are qualitatively distinct
Authors: Haynes Laurence W. , Semenenko Frances M. 
Published: April 2003

Abstractα‐Melanocyte‐stimulating hormone (α‐MSH) accelerates the regrowth of peripheral nerve axons in the rat following their transection (Verhaagen et al., Expl Neurol. 92, 451–454, 1986). The cellular mechanisms of this trophic response were investigated for several naturally occurring derivatives of α‐MSH using Nerve Growth Factor (NGF)‐stimulated quail sensory ganglion explants in vitro in which both neurite outgrowth and non‐neuronal cell behaviour could be more reliably observed and quantified. Neurite outgrowth was determined with a semi‐quantitative scoring assay. Glial migration into the outgrowth was quantified using a monoclonal antibody, GTE‐52, which labels the nuclei of Schwann cells. Des‐acetyl α‐MSH caused a marginal increase in the neurite outgrowth density which was significant at concentrations of 0.04 and 0.1 μg/ml. The response to acetylated (N‐acetyl, N,O‐diacetyl) forms of α‐MSH was characterized by fascicle formation by neurites which resulted in an apparent decrease in the neurite score and by the outgrowth of non‐neuronal cells. Using monoclonal antibody GTE‐52, which recognizes a glial nuclear antigen, these cells were identified as Schwann cells. N‐Acetyl, but not des‐acetyl α‐MSH increased the number of GTE‐52‐labelled cells in the NGF‐stimulated neurite outgrowth and stimulated their migration in the absence of neurites when NGF was omitted from the culture medium. Exposure of growing explants to two polyclonal antibodies against α‐MSH resulted in an increased neurite outgrowth density. The results support the hypothesis that α‐MSH peptides stimulate peripheral nerve growth by modulating the neurite sprouting response and demonstrate that the nature of the neurotrophic response to naturally occurring melanotropins depends on the existence of acyl substitution at the N‐terminal amino acid residue. A possible role of endogenous melanotropin peptides in the regulation of sensory nerve growth is discussed.