bluuebunny/crossref_metadata_2025_split huggingface dataset:
Capsaicin treatment to developing rats induces increase of noradrenaline levels in the iris without affecting the adrenergic terminal density
Authors: Luthman J. , Strömberg I. , Brodin E. , Jonsson G. 
Published: April 2003

AbstractThe effects of administration of capsaicin to developing and adult Sprague‐Dawley rats on substance P‐containing primary afferent and peripheral adrenergic nerves were analysed by histochemical and neurochemical techniques. In control rats a relatively dense innervation with substance Pimmunoreactive fibers was seen in the iris, while 10 weeks after a single neonatal injection of capsaicin (50 mg/kg s.c.) a moderate loss of substance P‐immunoreactive nerve fibers was observed. The substance P level was decreased by 60%, while the noradrenaline level, 3H‐noradrenaline uptake in vitro and the noradrenaline nerve density were unaltered. Repeated injections of capsaicin (2 × 50 mg/kg, 3 × 20 mg/kg s.c.) for 5 weeks to developing rats led to a very marked decrease of the substance P level and an almost complete disappearance of substance P‐immunoreactive fibers in the iris, when analysed at 10 weeks of age. The noradrenaline level in the iris was significantly increased (+42%), while no significant changes in noradrenaline level were observed in heart auricula or superior cervical ganglion. The uptake in vitro of 3H‐noradrenaline in irides and heart auriculae, as well as the noradrenaline terminal density in the dilator plate and surrounding blood vessels in the iris, were unaffected by repeated capsaicin treatment to developing rats. Capsaicin administration to adult rats (50 mg/kg s.c.), leading to a profound decrease in substance P, did not affect the noradrenaline levels at 24 hr after the injections. The results indicate that an extensive sensory denervation with capsaicin during development can induce an increase of noradrenaline levels in sympathetic nerve terminals in a target area (rat iris) with a rich SP‐ergic sensory innervation, although the sympathetic terminal density is not influenced. Furthermore the increase in noradrenaline seems to require an extensive loss of SP‐immunoreactive fibers and not solely a reduction of SP levels.
Polyamines induce precocious development in rats. Possible interaction with growth factors
Authors: Gilad Gad M. , Dornay Menashe , Gilad Varda H. 
Published: April 2003

AbstractThe study reports the effects of daily subcutaneous injections of the biogenic polyamines putrescine, spermidine and spermine (10 mg/kg each) given for a short postnatal period, on growth and development of rats. Polyamine treatment, while only slightly enhancing normal body weight gain, prevented the weight loss caused by surgical injury of 5‐day‐old animals. The treatment resulted in earlier eyelid and ear opening and in earlier maturation of righting and gripping responses. Increased number of neurons in the superior cervical ganglion that is caused by polyamine treatment, could not be prevented by castration of newborn rats, thus excluding the testes as a site through which polyamines may exert their action. An apparent increase in immunohistochemically detectable nerve growth factor was evident in iris and submaxillary salivary gland of polyamine‐treated animals, but no change in epidermal growth factor immunohistochemistry was detected in the salivary gland. We conclude: (1) treatment of newborn rats with polyamines can accelerate somatic and neurobehavioral development; (2) further studies are required in order to verify and quantitate the effects of polyamines on growth factors, and (3) the results imply that exogenous polyamines may exert their growth‐promoting effects on a number of cell types when these cells experience periods of polyamine dependence.
Antioxidant enzymatic activities and resistance to oxidative stress in primary and subcultured rat astroglial cells
Authors: Vanella A. , Avola R. , Condorelli D. F. , Campisi A. , Costa A. , Stella A. M. Giuffrida , Perez‐Polo J. R. 
Published: April 2003

AbstractThe survival of neural tissues depends in part on the balance between the formation of free radicals due to oxidative metabolism and the transformation of the free radicals to non‐toxic compounds. Serial subculture of rat glial cells as described here resulted in a decrease of the specific activities of several antioxidant enzymes and a glial specific marker for astrocytes. Thus, there was an increased susceptibility to oxidative stress in cultures by the third passage. These subcultured glial cell cultures may represent a useful model for the study of free radical induced neural damage that may be relevant to CNS trauma and aging.
The interaction of substrate and taurine modulates the outgrowth from regenerating goldfish retinal explants
Authors: Lima L. , Matus P. , Drujan B. 
Published: April 2003

AbstractRetinal growth from expiants attached to different substrates was evaluated in the absence and the presence of various concentrations of taurine. Fiber thickness was higher in poly‐l‐lysine, collagen and laminin than in the other substrates tested. Explants on wheatgerm, soybean, and red kidney bean lectins did not show emission of neuntes at 5 days in culture; growth on laminin was very poor at this period of time. By day 10 nerve growth index was possible to evaluate on soybean and laminin. Outgrowth from retinal explants on wheatgerm lectin was only observed in the presence of taurine. The percentage of growing explants on laminin was increased by the amino acid. Emission of neurites from explants on concanavalin A and lentil lectin was constant from 5 to 10 days in culture and was not accelerated or increased by taurine. Growth on poly‐l‐lysine and collagen was stimulated by the addition of taurine in a concentration‐dependent manner. The amino acid stimulates outgrowth from expiants attached to peanut lectin in a bell‐shaped concentration dependency similar to that observed on poly‐l‐lysine. The effect of taurine on retinal expiants is substrate‐dependent, as an indication of the interaction of soluble molecular components plus charge and structure of the extracellular matrix in order to modulate the outgrowth from regenerating tissue.
Nerve growth factor induces neurite outgrowth in a clone derived from an NGF‐insensitive human neuroblastoma cell line
Authors: Reynolds C. Patrick , Perez‐Polo J. Regino 
Published: April 2003

AbstractNerve growth factor (NGF) plays a trophic and tropic role in the development of vertebrate sympathetic and sensory ganglia; however, the precise nature of the NGF effect(s) is not understood. Study of NGF‐responsive human neuroblastoma cell lines allows characterization of NGF‐induced neunte outgrowth in cells not dependent on NGF for survival. The human neuroblastoma line SK‐N‐SH did not significantly extend neuntes in response to NGF, but did show an increase in cell number. By contrast, a clone of the line, SH‐IN, extended neuntes in response to NGF or dibutyryl cyclic AMP, and showed inhibition of cell proliferation. Thus, cells capable of morphological differentiation in response to NGF can be cloned from neuroblastoma cell lines in which the majority of the cells fail to extend neurites even in the presence of NGF.
Postnatal development of the excitatory amino acid system in visual cortex of the rat. Changes in uptake and levels of aspartate and glutamate
Authors: Erdö Sandor L. , Wolff Joachim R. 
Published: April 2003

AbstractThe postnatal changes of aspartate (Asp) and glutamate (Glu) levels, as well as the development of the high‐affinity uptake of [3H]d‐Asp were examined in the visual cortex of rats, aged 2–360 days. Perinatal (day 2) levels of Asp were relatively lower than those of Glu, i.e. about 30 and 60% of the respective values for adults (day 180). Both Asp and Glu levels showed a rapid increase during the second and third postnatal weeks. Asp reached its maximal concentration (day 20) a few days earlier than Glu (day 25). Thereafter, both Asp and Glu levels slowly declined to the adult values which were reached by day 90 and remained unchanged up to day 360. The uptake of d‐Asp was low in newborns (5% of that in adult) and progressively increased with age up to about day 20, when adult values were attained. The increase of Asp and Glu levels showed a close correlation with the maturation of uptake capacity. Our findings indicate that the developmental increase of Asp and Glu levels is associated with the maturation of excitatory innervation in the visual cortex, but they do not support the concept of a transient Asp/Gluergic innervation of the immature visual cortex.
Activation of the glycine site associated with the NMDA receptor is required for induction of LTP in neonatal hippocampus
Authors: Oliver M. W. , Larson J. , Lynch G. 
Published: April 2003

AbstractThe role played by the glycine site associated with the NMDA receptor in inducing long‐term potentiation (LTP) in neonatal hippocampus was examined. An antagonist of the glycine site, 7‐chlorokynurenic acid (Cl‐Kyn), completely blocked both the short‐term and the long‐term potentiation associated with theta burst stimulation (TBS) linked to NMDA receptor activation in slices from hippocampus at postnatal days 10–16; this effect was reversed by the glycine agonist, d‐serine. Analysis of the TBS‐evoked responses showed: (1) a developmental alteration in the burst response morphology that may be related to maturation of GABA‐mediated inhibition; and (2) that, unlike 2‐amino‐5‐phosphonovalerate (APS), Cl‐Kyn did not reduce any portion of the burst response. These results suggest that stimulation of the glycine site coupled to the NMDA receptor complex is necessary to induce LTP in neonatal tissue and that two NMDA receptor types may be present in the hippocampus.
Proteoglycan synthesis by clonal skeletal muscle cells during in vitro myogenesis: Differences detected in the types and patterns from primary cultures
Authors: Miller Raymond R. , Rao Jasti S. , Burton Willis V. , Festoff Barry W. 
Published: April 2003

AbstractProteoglycan synthesis by two clonal murine skeletal muscle cell lines, G8‐1 and C2, was examined. Cultures of skeletal muscle cells at both the myoblast and myotube stages were radiolabeled using [35S]sulfate as a precursor. The proteoglycans of the cell layer and medium were separately extracted and isolated by ion exchange chromatography on DEAE‐Sephacel followed by gel filtration chromatography on Sepharose CL‐2B. The cell layer proteoglycans eluted from Sepharose CL‐20 as a single peak with a Kav of 0.66 and contained glycosaminoglycan chains with an average molecular weight of 20,000. The glycosaminoglycan chains were composed of nearly equal mixtures of chondroitin sulfate and heparan sulfate with the exception that C2 myoblast cultures contained larger amounts of heparan sulfate. Of interest, this line differentiates more rapidly in our laboratory than G8‐1. The medium proteoglycans also eluted from Sepharose CL‐2B as a single peak with a Kav of 0.66 but contained glycosaminoglycan chains with an average molecular weight of 32,000. Based upon enzymatic and chemical analysis, the medium glycosaminoglycan chains were composed of a mixture of chondroitin sulfate (71–80%) and heparin sulfate (19–22%). Following chondroitinase ABC digestion, the predominant disaccharide released from all glycosaminoglycan fractions was chondroitin‐4‐sulfate. When the extracted cell layer proteoglycans were chromatographed on Sepharose CL‐28 in the absence of detergent, a small but consistent proportion (14–18%) eluted in the void volume, suggesting the association of at least a portion of this proteoglycan with cellular lipid. These differences distinguish proteoglycan metabolism in fusing clonal lines from primary muscle cell cultures suggesting their utility in evaluating the contribution of these macromolecules in myogenesis.
Synapse formation on trochlear motor neurons in relation to naturally occurring cell death during development
Authors: Hirano S. , Kumaresan K. , Ali M.M. , Sohal G.S. 
Published: April 2003

AbstractAbout half of the trochlear motor neurons die during the course of normal development. The present study was undertaken to determine whether the afferent synapses form before the onset of motor neuron death and also to determine whether the number of synapses differs between the healthy and degenerating trochlear motor neurons. Brains of duck embryos from days 10 to 20 were prepared for quantitative electron microscopical observations on synaptogenesis. Results indicate that synapses form on the trochlear motor neuron soma before cell death begins suggesting that afferent input is in a position to exert an influence on survival or death of motor neurons. There were no significant differences in the number of synapses between the healthy and dying neurons during the period of cell death. This observation suggests that the mechanism by which afferent synapses could be involved in neuron survival or death is not related to the number of synapses on the cell soma. The number of synapses on the cell process, synaptic transmission and/or molecules released at the synapses are likely candidates for the mechanism of action of afferent input.
Macrophage‐like cells originate from neuroepithelium in culture: Characterization and properties of the macrophage‐like cells
Authors: Hao C. , Richardson A. , Fedoroff S. 
Published: April 2003

AbstractCultures of astroglia from C3H/HeJ mice, which are resistant to bacterial cell wall polysaccharide (LPS), initiated from embryos of Theiler stage 14 (9 days of gestation) up to Theiler stage 25 (17 days of gestation) as well as newborn animals, when subjected to nutritional deprivation, i.e. non‐feeding of cultures, form large numbers of macrophage‐like cells. These cells express Mac‐1, Mac‐3, F4/80 and Fc antigens. The cells are negative for GFAP, positive for vimentin, express Ia antigen and take up DiL‐Ac‐LDL. They are positive to non‐specific esterase, secrete lysozyme and are phagocytic. Their morphology and ultrastructure closely resemble those of macrophages. Cultures initiated from neuroepithelium of Theiler stage 13 (8.5 days of gestation), before vascularization, when subjected to nutritional deprivation, also produce macrophage‐like cells. Using spleen colony assay and methyl cellulose cultures, we were unable to detect the presence of hemopoietic (macrophage) precursor cells in astroglia cultures. This supports the hypothesis that the macrophage‐like cells are of neuroectodermal origin and probably correspond to resident microglia of the CNS. Using nutritionally deprived astroglia cultures, a procedure was developed for isolation of macrophage‐like cells and production of highly enriched macrophage‐like (microglia) cultures.
Quantitative histochemical changes in enzymes involved in energy metabolism in the rat brain during postnatal development. II. Glucose‐6‐phosphate dehydrogenase and β‐hydroxybutyrate dehydrogenase
Authors: Bilger Anne , Nehlig Astrid 
Published: April 2003

AbstractThe postnatal maturation of glucose‐6‐phosphate and β‐hydroxybutyrate dehydrogenase activity was assessed by histochemistry in rats at eight postnatal stages, P0, P5, P10, P14, P17, P21, P35 and the adult stage. Enzyme activities were revealed on cryostat brain sections with nitroblue tetrazolium. Both enzyme activities were low and homogenous at birth, and increased to reach a peak in all areas studied, at P17 for β‐hydroxybutyrate dehydrogenase and at P21 for glucose‐6‐phosphate dehydrogenase. Then, glucose‐6‐phosphate dehydrogenase activity decreased regularly by 20–49% from P21 to adult stage, except in cerebellar white matter where activity did not change after P21. β‐hydroxybutyrate dehydrogenase activity decreased regularly from P17 to adult stage in globus pallidus, hippocampus, thalamus, brainstem, genu of corpus callosum and cerebellar white matter. In sensorimotor cortex, medial geniculate body, caudate nucleus, hypothalamus and inferior colliculus, β‐hydroxybutyrate dehydrogenase activity stayed stable between P17 and P35 and decreased thereafter to adult levels. Finally, in parietal, auditory and cerebellar cortices, β‐hydroxybutyrate dehydrogenase activity either stayed stable or slightly increased after P17. The present study shows that there is a quite good correlation between postnatal changes in cerebral glucose‐6‐phosphate and β‐hydroxybutyrate dehydrogenase activities and the importance of pentose phosphate pathway and ketone body utilization in the developing brain. Our results also reflect the regional heterogeneity of β‐hydroxybutyrate utilization in the adult rat brain, translating into a remaining high activity of β‐hydroxybutyrate dehydrogenase in cerebral cortex.
Screening of adrenal medullary neuropeptides for putative neurotrophic effects
Authors: Unsicker Klaus , Stögbauer Florian 
Published: April 2003

AbstractChromaffin granules, the secretory organelles of the neuron‐like adrenal medullary chromaffin cells, have previously been shown to store and liberate neurotrophic activities that support in vitro survival of several neuron populations including those innervating the adrenal medulla. Molecules resembling fibroblast growth factor and ciliary neurotrophic factor have been identified among these activities. Since chromaffin granules store a variety of neuropeptides and many neuropeptides can have pleiotropic effects on neuronal growth and maintenance we have tested 24 different neuropeptides for their capacities to promote survival of embryonic chick ciliary, dorsal root and sympathetic ganglionic neurons. Peptides tested included several derivatives of proenkephalin (Leu‐ and met‐enkephalin, fragments BAM 22, B, F and E), somatostatin, substance P, neuropeptide Y, neurotensin, VIP, bombesin, secretin, pancreastatin, dynorphin B, dynorphin 1–13, β‐endorphin, alpha‐, beta‐, and gamma‐MSH. Control cultures received saturating concentrations of ciliary neurotrophic or nerve growth factor (CNTF; NGF), or no trophic supplements. At 1 × 10−5 M leu‐ and met‐enkephalin as well as somatostatin supported sympathetic neurons to the same extent as NGF. At the same concentrations, leuenkephalin, the proenkephalin fragments BAM 22 and E, and somatostatin maintained about half of the dorsal root ganglionic neurons supported by NGF, but were not effective on ciliary neurons. VIP promoted the survival of approximately 50% of the ciliary and embryonic day 10 dorsal root ganglionic neurons as compared to saturating amounts of CNTF, but required the presence of non‐neuronal cells in the cultures to be effective. Neurotensin (1 × 10−5M) had a small effect on ciliary neurons. All other peptides had no effect on any neuron population tested. Our results suggest that neuropeptides that occur in the adrenal medulla may play a role for the maintenance of cholinergic, sensory, and sympathetic neurons innervating the adrenal medulla.
In vitro differentiation inhibits the migration of cultured neonatal rat cortical astrocytes transplanted to the neonatal rat cerebrum
Authors: Hatton James D. , Hoi Sang U. 
Published: April 2003

AbstractNeonatal rat astrocytes transplanted into the rat cerebrum migrate extensively. However, few of the molecular signals determining this migration have been defined. In the present study, in vitro modifications were designed to examine whether differentiation prior to transplantation would affect the magnitude or pattern of astrocyte migration in the neonatal host brain. Here, cortical astrocytes were collected from the brains of rats 1–3 days postpartum and purified by culturing them in DME medium supplemented with 10% calf serum. After 14–21 days, astrocytes were labelled with fluorescein‐tagged latex microspheres for 16 hr; the label was then removed and replaced with either fresh medium or fresh serum‐free medium plus 1 mM dbcAMP. After 48 hr, cells were harvested and then transplanted into the right frontal cerebrum of neonatal rats at 3 days postpartum by injection with a hand‐held Hamilton syringe. Animals were sacrificed at 3, 6, 9, 15, 21 and 28 days after inoculation and their brains examined with fluorescence microscopy. Astrocytes not exposed to dbcAMP prior to implantation migrated along the corpus callosum, internal capsule, glial limitans, ventricular linings and the hippocampal structure. They also appeared to migrate in a radial fashion toward the periphery from the ventricular lining. Astrocytes treated with dbcAMP prior to transplantation did not appear to migrate into the neonatal parenchyma, remaining confined to the injection site for at least 6 days. Migration then appeared to commence at a normal rate after 9 days. Thus, neonatal cortical migrate outward in a pattern similar to that defined by the radial glia. Astrocytes differentiated by dbcAMP treatment, however, do not appear to migrate to any large degree in the neonatal brain until the treatment effect diminishes, suggesting that differentiation may represent an end‐point to glial migration in the neonatal host brain.
Postnatal development of functional dopamine, opioid and tachykinin receptors that regulate acetylcholine release from rat neostriatal slices. Effect of 6‐hydroxydopamine lesion
Authors: Pérez‐Navarro Esther , Alberch Jordi , Marsal Jordi 
Published: April 2003

AbstractIn the present work we have studied the postnatal development of functional dopamine, opioid and tachykinin receptors, which regulate cholinergic activity in the neostriatum. The release of endogenous acetylcholine from rat striatal slices was measured using a chemiluminescent method. We have observed that the inhibition mediated by dopamine through D2 receptors was not detectable until postnatal day 10, whereas the inhibition mediated by opioid receptors was detectable at postnatal day 15 for δ‐receptors ([D‐Pen2, D‐Pen5]‐enkephalin) and at postnatal day 21 for μ‐receptors ([D‐Ala2, Gly(ol)5]‐enkephalin). Excitatory effect mediated by tachykinins through NK1 ([Sar9, Met(O2)11]‐Substance P), NK2 ([Nle10]‐Neurokinin A4–10), or NK3 (senktide) receptors was already detectable at postnatal day 5.In order to examine the influence of dopamine in the development of tachykinin and opioid systems in the neostriatum, we induced dopamine deficiency by intraventricular injection of 6‐hydroxydopamine at postnatal day 3. We observed an increase in senktide‐evoked acetylcholine release at postnatal day 30. The effect produced by [Sar9, Met(O211]‐Substance P and [Nle10]‐Neurokinin A4–10 was not modified. Furthermore, at postnatal day 35, we could observed that the two opioid receptor agonists have no effect.Our results show that dopamine, tachykinins and opioids are already able to mediate the modulation of acetylcholine release in early stages of development with a different pattern of postnatal development. Furthermore, the integrity of a dopaminergic system plays an important role in the functional development of the neostriatal cholinergic neurons which are differentially modulated by opioids or tachykinins.