摘要:

AbstractVarious factors capable of inducing morphological differentiation of neuroblastoma cells were studied to determine whether they may also specifically regulate cholinergic function in human cholinergic neuroblastoma cells MC‐IXC. Choline acetyltransferase (CAT) activity was monitored to reflect cholinergic function while Mg2+ATPase activity was monitored to reflect effects which are not related specifically to neuronal function. Among the agents, dimethylsulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMA), D‐α‐tocopherol, ascorbic acid and dibutyryl‐cAMP, only low doses of DMSO were found to selectively inhibit CAT activity while Mg2+ATPase activity along with population growth remained unaffected. Of the three chemically related organic compounds tested (DMSO, DMF, DMA), DMSO was the least potent with regard to inhibition of population growth and Mg2+ATPase activity while DMA was the most potent inhibitor. Sodium butyrate caused a decline in CAT activity while retinoic acid induced an enhancement. The combination of sodium butyrate with retinoic acid caused an enhancement of CAT activity similar in magnitude to that observed with retinoic acid alone. Lastly, CAT activity was found to be independent of population density unlike that in different neuroblastoma cell lines.8,12,19

ISSN:0736-5748    

DOI:10.1016/0736-5748(84)90041-8

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractGrowth patterns in selected areas of rabbit brain were studied neurochemically by assaying for norepinephrine, dopamine and serotonin from the neonatal to adult stages of development. These measurements showed that the various monoamines reached adult concentrations at different rates within a brain region; each region had a unique pattern of amine development. Changes in content were most marked in the first 2 weeks of life. Concentration increases were pronounced for norepinephrine and serotonin in the hypothalamus and for dopamine in the caudate nucleus. By contrast, norepinephrine concentrations in the pons‐medulla and colliculi were relatively stable. The marked changes and differences in amine concentrations of maturing rabbit brain provide basic data on monoaminergic innervation of discrete regions and indicate the rabbit merits consideration in neurochemical and physiologic studies on the development of neurotransmission.

ISSN:0736-5748    

DOI:10.1016/0736-5748(84)90042-X

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractEffects of NaCl, (+)‐and (−)‐sultopride on striatal [3H]spiperone binding was investigated in 7‐day, 70‐day and 2‐year‐old rats. The amount of specific [3H]spiperone binding was the highest at 70 days and the value at adult stage was significantly (P<0.001) higher than those at 7 days and 2 years. NaCl (100 mM) significantly increased [3H]spiperone binding in neonatal (P<0.01), adult (P<0.05) and senescent (P<0.05) animals. Scatchard analysis showed that the Bmax of low‐affinity [3H]spiperone binding was significantly elevated by 100 mM NaCl compared to the value in control of adult animals. More potent inhibition of (−)‐sultopride for [3H]spiperone binding than that of the (+)‐enantiomer at adult stage was also observed at neonatal and senescent stages. NaCl (100 mM) significantly enhanced inhibitory activities of (+)‐ and (−)‐sultopride at every stage. It is suggested that stabilizing effect of Na+on dopamine (DA) receptor complexes and increasing effect of Na+on binding affinity of benzamide to DA2receptors keep functions through development and aging.

ISSN:0736-5748    

DOI:10.1016/0736-5748(84)90043-1

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractMicrotubules were studied in parallel fibres and Purkinje cell dendrites of 14‐day‐old normal and propylthiouracil‐treated rats after fixation of the cerebellum at room and low temperature (4°C). In both control and propylthiouracil‐treated animals, nearly all the microtubules of parallel fibres disappeared after fixation at low temperature. In Purkinje cell dendrites of control animals, 60% of the microtubules persisted at low temperature. Propylthiouracil treatment led to a 78% decrease in the density of these cold‐stable microtubules. In contrast, the density of cold‐labile microtubules remained normal. Administration of low doses of thyroxine to the propylthiouracil‐treated rats produced a rapid increase in the density of cold‐labile microtubules, but long‐term treatment with the hormone was necessary to obtain normal density of cold‐stable microtubules. Thyroid hormone thus seems to regulate some properties of microtubules involved in their resistance to fixation at low temperature. These properties could be of importance in growth and branching of dendrites.

ISSN:0736-5748    

DOI:10.1016/0736-5748(84)90044-3

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractMaternal alcohol abuse has been associated with reduced neural cell number and abnormal cell differentiation and organization in many regions of the developing mammalian brain. Experiments were conducted to determine whether changes in the neural precursor cells could be detected in primary culture following maternal alcohol consumption during the early proliferative period of the fetal brain growth spurt. Alcohol was administered to pregnant mice in the drinking water from days 11 to 19 of gestation. There was no alcohol‐related increase in the incidence of fetal mortality or malformation, but fetal body and brain weights were reduced. When disaggregated cells from the day 19 fetal neopallium were grown in culture, there was a reduction in the number of astroglial colonies yielded in 42% of alcohol‐exposed brains. This effect was expressed as a reduction in the absolute plating efficiency (APE) of the neural precursor cells. The APE was reduced as much as 80% in severely affected brains. There was no alcoholrelated difference in thein vitromorphogenesis of the astroglial colonies. Observations of the proliferative neural cellsin situsuggest that there is an impaired recruitment of all neural cell types, but that the reduced APE reflects primarily a proportionate increase in the number of immature neurons among the cells obtained from the fetal neopallium. It appears that a prolongation of mitosis may be resulting in a general developmental delay in the fetal neocortex.

ISSN:0736-5748    

DOI:10.1016/0736-5748(84)90045-5

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractPalmitic, linoleic, arachidonic, and docosahexaenoic acids were used as substrates to study fatty acid activation in the mouse brain and liver during postnatal development. Long‐chain acyl coenzyme A synthetase showed peak activity during the period of rapid oligodendroglial proliferation and myelination. In brain, activation of linoleic and arachidonic acids was highest, followed by palmitic and docosahexaenoic acids. In liver, no appreciable change in enzyme activity was seen during the period of development studied. Palmitic and arachidonic acids showed the highest rate of activation, followed by docosahexaenoic acid. These ontogenic data suggest the presence of a single long‐chain acyl coenzyme A synthetase in brain.

ISSN:0736-5748    

DOI:10.1016/0736-5748(84)90046-7

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractSubstance P‐like immunoreactivity has been observed in fetal and adult cranial sensory ganglia. It first appears at day 16 of gestation in sensory neurons of trigeminal, superior‐jugular, petrous and nodose ganglia, as well as in the autonomic myenteric plexus, and at day 17 in cervical dorsal root ganglion cells. Substance P immunoreactivity can be visualized much earlier (day 12) in the central nervous system. The ganglionic immunoreactivity subsequently increases during fetal life but drops at birth. The reactive material is first diffuse, then slowly becomes granular, and is mostly concentrated in coarse perinuclear inclusions in adult sensory neurons. Most substance P‐positive neurons in trigeminal and superior‐jugular ganglia are small, but medium‐sized and large positive neurons are also observed in the trigeminal, petrous and nodose ganglia.Our observations give a precise picture of the development of substance P immunoreactivity in sensory neurons and are in general agreement with previous reports on some fetal and adult rat sensory ganglia. They indicate that in the rat, maturation of peripheral substance P‐containing sensory neurons is slower than that of central substance P neurons or equivalent sensory neurons in other species. The examination of fetal material allows the observation of numerous immunoreactive sensory neurons which cannot be visualized after birth. We hypothesize a possible different embryonic origin (neural crest or placodal) for small nociceptive and larger substance P‐containing neurons in rat cranial sensory ganglia.

ISSN:0736-5748    

DOI:10.1016/0736-5748(84)90047-9

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe properties of taurine, hypotaurine and β‐alanine uptakes were compared in brain synaptosomal preparations from 6‐day‐old and adult mice. The uptakes of these structurally related amino acids resembled each other, being concentrative, sodium‐dependent and inhibited by the same analogues. The absolute sodium requirement of uptake was already evident in developing brain. The affinity of the lowaffinity uptake for taurine was higher in immature than in adult brain. Both affinity and maximal velocity increased in hypotaurine uptake during development, whereas in β‐alanine uptake only the maximal velocity did so. The efficient synaptosomal taurine and hypotaurine transport systems in immature brain could contribute to the high taurine level in developing brain.

ISSN:0736-5748    

DOI:10.1016/0736-5748(84)90048-0

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe differentiation of neurons and glial cells in the spinal cord of the zebrafish was studied by means of immunohistochemistry, using antisera against the 68 kD subunit of neurofilament (anti‐NFP68) and against glial fibrillary acidic protein (anti‐GFAP), both isolated from the bovine brain. Anti‐NFP68 and anti‐GFAP reactivity appear in the spinal cord at about 60 h after fertilization. At that time the anti‐NFP68 reactivity is detectable in the dorsal Rohon‐Beard neurons. About 12 h later, NFP68 positive neurons appear in the prospective motor column. In this respect the differentiation of the primary sensory system precedes that of the spinal motor system. During development the configuration of the glial cell processes changes from a horizontal arrangement in embryos to a radial frame work in larvae and in adults. From these observations together with data on the organization of the adult spinal motor column28we conclude that the motoneurons of the white and those of the red myotomal muscle fibers may have different origins in the neuroepithelial germinal layer. The anti‐NFP68 serum recognizes a 120 and a 94 kD component of fish neurofilaments. Thus the subunit composition of neurofilament in fishes differs from that in mammals.

ISSN:0736-5748    

DOI:10.1016/0736-5748(84)90049-2

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractSerum‐free, chemically defined media have been reported to provide suitable conditions for growth and proliferation of mammalian skeletal muscle, but there is no information regarding the ability of myotubes to develop normal electrophysiological properties in these media. We have recorded transmembrane resting and action potentials from rat skeletal myotubes grown in both serum‐containing (GM) and serum‐free chemically defined (CDM) growth media. Muscle cells in CDM do not develop as high resting Em as their counterparts in conventional growth media. CDM myotubes also had a lower incidence and frequency of spontaneously occurring action potentials. Treatment with ouabain or decrease in temperature of the recording medium reduced resting Em of both GM and CDM cells to the same level. We found that the sensitivity of CDM cells to ouabain was about 10‐fold higher than that of GM cells. An increase in temperature of the recording medium increased Em of GM myotubes but not of CDM myotubes. The change in resting Em in response to a 10‐fold change in extracellular K+‐ion concentration was the same for both groups of cells thus indicating that there was no difference in membrane permeability to K+‐ion. We conclude that the difference in Em can be accounted for largely, if not entirely, by differences in activity or amount of electrogenic Na+‐K+ATPase.

ISSN:0736-5748    

DOI:10.1016/0736-5748(84)90050-9

出版商:Wiley    

年代:2003

数据来源: WILEY