摘要:

AbstractThe effects of serotonin (5‐HT) on morphofunctional development of hippocampal cultures derived from newborn rats were studied. It was established that systematic addition of 5‐HT to nutrient medium during cultivation stimulates neuropil development, axon myelination and synaptogenesis. Electrophysiological studies of hippocampal cells in 5‐HT treated cultures showed earlier exhibition of spontaneous activity and an increased number of spontaneously firing neurons and prevalence of periodic (bursting) type of discharges. These results indicate that 5‐HT stimulates the differentiation of hippocampal cells in tissue culture.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90015-1

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractGlutamate has been suggested to be the neurotransmitter of the granule cells in cerebellar cortex. Autoradiographic studies using very low concentrations (1μM range) of 2‐3‐[3H]l‐glutamate or 2‐3‐[3H]l‐glutamine have shown that both amino acids were preferentially taken up in the molecular layer of the cerebellar cortex of adult rats, but [3H]Glu accumulated essentially in glial cells, while Gln did not show a cellular preference (de Barryet al., Neuroscience 7,1289–1297,1982).In this paper we show that during development the preferential accumulation of [3H]Glu and [3H]Gln are the same as in the adult but, in addition, at young ages (7–10 days) [3H]Gln accumulated in replicating cells of the external granular layer (EGL). The absence of glutamine synthetase in the EGL cells suggests that this accumulation of exogenous Gln might be used for the synthesis of purines and pyrimidines required for the active multiplication of these cells and is not correlated to neurotransmission. The metabolism of [3H]Gln was slow at young ages and changed during development. The metabolism of the Glu taken up was constant throughout development which is consistent with the hypothesis that high affinity Glu uptake is mainly a glial cell property and that the increasing accumulation rate during development reflects glial maturation.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90016-3

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe concentration of cerebrosides and their fatty acid profile were determined in different regions of the brain, namely cerebrum, cerebellum and medulla oblongata, of normal infants (weighing>2500 g) and of the two categories of small‐for‐date term infants (weighing 2000–2500 g and<2000 g). Cerebroside concentration, in general, was observed to be low in the three regions of the brain from small‐for‐date infants. The magnitude of reduction varied with the region. The cerebrum, in particular, showed a significant reduction in the concentration of cerebrosides in the case of low‐birth‐weight infants. The nonhydroxy fatty acid distribution of cerebrosides indicated a lower proportion of long‐chain fatty acids, namely lignoceric (24:0) and nervonic (24:1) acids, in the cerebellum and the medulla oblongata of small‐for‐date infants, and also in the cerebrum of those weighing<2000 g. The observed changes in the concentration of cerebrosides and their fatty acid profile point to the possibility of impaired myelinization of the brain in small‐for‐date infants.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90017-5

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractConcentrations of transferrin in plasma, cerebrospinal fluid (csf) and brain of fetal and newborn rats have been estimated by radial immunodiffusion assay. Transferrin was detected in both csf and brain at the earliest age investigated (12 days gestation). The plasma concentration increased throughout the gestational period studied and in the postnatal period: the overall increase was about 10‐fold. In contrast, although the csf transferrin concentration increased by 3 times between 12 and 22 days (term) there was a considerable decline on reaching adult age. Brain transferrin concentration was highest at 18 days gestation. These results are important background information for studies of the significance of transferrin in brain development.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90018-7

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractPresence of keratin was observed in the notochordal plate of 10‐day rat embryos. The characteristic changes in the appearance of the notochord during the following days of gestation were also observed in sections stained by immunofluorescence with keratin antisera. On day 12, the keratin‐positive notochordal plate had become a cylindrical structure closely apposed to the ventral surface of the spinal cord. The distance between notochord and spinal cord progressively increased at later stages. The expression of keratin was also studied by the Avidin‐Biotin complex method on 4 chordomas, tumors originating from intraosseous notochordal vestigial remnants. In accordance with the developmental study all chordomas were keratin‐positive.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90019-9

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe role of gangliosides in neuronal differentiation was studied by adding a mixture of bovine brain gangliosides to mouse neuroblastoma cells which were induced to differentiate through the application of γ‐aminobutyric acid (GABA) or sodium bromide (NaBr). GABA or NaBr was applied to 5‐day‐old cultures at concentrations ranging from 10−4to 10−5M. The cells were exposed to these substances over short periods of time (2 days). A mixture of bovine brain gangliosides was added to the 7‐day‐old cultures for 24–28 h. Electron microscopy revealed that ganglioside‐induced morphological differentiation was accompanied by a significant number of mature synapse‐like contacts. The GM1 gangliosides fraction apparently plays an important role in the formation of mature synapses, since none were observed when the GM1 was removed from the ganglioside mixture.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90020-5

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe monoclonal antibody anti‐BSP‐2 recognizes three glycosylated peptide chains of 180,000, 140,000 and 120,000 daltons in extracts from adult mouse forebrain and cerebellum. In extracts of embryonic or neonatal brain, it recognizes a different form, migrating as a broad band of higher molecular weight on SDS polyacrylamide gels. This report describes the distribution of the antigen BSP‐2 in developing mouse cerebella using a sensitive immunoperoxidase technique at the electron microscope level. As early as 3 days after birth the antigen can be detected on the surface of all cerebellar neurons, including neuroblasts in the external granular layer, basket and stellate neurons and Purkinje cells. In addition, radial glial fibres (astrocytes) terminating on the pial surface contain BSP‐2. At later stages a pronounced surface labelling of parallel fibres is observed. Migrating granule cell perikaryal membranes possess the glycoprotein. The results are discussed in relation to the apparent identity of BSP‐2 and the cell adhesion molecule N‐CAM and its physiological properties.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90021-7

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractChanges in neuronal numbers during the development of the chick embryo paravertebral sympathetic nervous system have been examined using cell culture techniques. Early sympathetic ganglia contain predominantly cells having neuronal phenotypes and these increase in number until embryonic day 9. Subsequently there is a large decrease in the number of neurons and an increase in the population of non‐neuronal cells. Thisin vivopattern is maintained when the neurons are grownin vitro, where Nerve Growth Factor more readily prevents the death of neurons cultured from 12‐day or older embryos than those from earlier stages of development.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90022-9

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractImmunocytochemical methods have in recent years played a more important role in investigations of the development and function of glial cells in the nervous system because of their potential to distinguish between different cell populations. This short review attempts to highlight the value of this approach and summarizes the major cell‐type markers currently available. These include, for the astrocyte, GFA protein, S‐100 protein, vimentin, αα‐enolase and α‐2 glycoprotein. For the oligodendrocyte, myelin basic protein, the Wolfgram proteins, 2′,3′‐cyclic nucleotide 3′‐phosphohydrolase, myelin associated glycoprotein, proteolipid protein, galactocerebroside, carbonic anhydrase and glycerol 3‐phosphate dehydrogenase and other glial cell markers recognized by monoclonal antibodies are discussed. The application of these techniques to the study of the developing brain (and in particular the rodent cerebellum) are reviewed. It has proved possible to follow the development of distinct populations of astrocytes and oligodendrocytes from a very precocious age to the adult situation, thus providing new insight on the relationship between glial cells and neurons during normal and abnormal histogenesis.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90023-0

出版商:Wiley    

年代:2003

数据来源: WILEY

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90024-2

出版商:Wiley    

年代:2003

数据来源: WILEY