ISSN:0736-5748    

DOI:10.1016/0736-5748(88)90057-3

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe principles of transplantation immunobiology are described and discussed in terms of their applicability to neural grafting, a newly emerging field dedicated to the ultimate goal of reconstituting central nervous system deficits with normally functioning tissue replacements. Unique anatomic and physiologic features of the eye, which are responsible for the phenomenon of immunologic privilege, are compared with the brain and considered in terms of their relationship to the principles of transplantation. The existence of immune privilege in the brain and the newly acquired understanding of immunologic privilege in the eye may offer strategies by which neural grafters can achieve significantly greater graft acceptance.

ISSN:0736-5748    

DOI:10.1016/0736-5748(88)90058-5

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe function of NGF in chick embryos was studied by injecting antibodies to mouse nerve growth factor (NGF). The uptake of mammalian antibodies into the 8‐ to 15‐day‐old chick embryo was followed by an enzyme‐linked immunoassay. Normal rabbit antibodies (250 μg) were administered to the yolk, of which less than 5% was found in the embryo (300 ng of IgG per g wet wt of embryo). The concentration was proportionally lower when 100 μg anti‐NGF antibodies were injected (40 ng/g). The concentration of anti‐NGF antibodies was 1.5 times higher following injection directly into the body of the embryos. The effects of injecting antibodies at days 3–7 were studied in 10‐day‐old embryos by measuring the diameter frequencies of neurons in sympathetic and sensory ganglia. In comparison with controls, significantly smaller neurons were found in the sympathetic ganglia in embryos directly injected with anti‐NGF. In the spinal ganglia, distribution of neuron diameters did not differ between anti‐NGF‐treated embryos and controls. Finally, the ability of different antibodies to mouse NGF to inhibit thein vitroactivity of recombinant chick NGF was investigated. Total block was found at 1000–2000 ng of IgG per ml for most of the antibodies tested, levels not reached when injecting the embryo with antibodies to NGF. We conclude that the main reason for the limited effects in chick embryos by injection of NGF antibodies is due to the low levels of penetration of the anti‐NGF IgG into the embryo.

ISSN:0736-5748    

DOI:10.1016/0736-5748(88)90059-7

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractConditions are described which allow the preparationin vitroof pure (>95%) microglial cell cultures isolated from newborn rat brain. Such ameboid cells cultivatedin vitrocan efficiently phagocytize opsonized latex beads and are capable of ingesting more (100–200 beads of 1.1 μm diameter per cell) and larger (6.4 μm) particles than other nerve cells, such as oligodendrocytes and astroglia. The microglial cells also show an important ecto‐NAD+glycohydrolase activity which is characteristic of phagocytic cells. We noted that the phagocytic capacity and ecto‐NAD+glycohydrolase of these cells were correlated and increased notably during thein vitroculture.Microglia cultivatedin vitroappear to be a good model to study the activation of phagocytic properties in the central nervous system and corresponding modulation by natural or pharmacological immunomodulators.

ISSN:0736-5748    

DOI:10.1016/0736-5748(88)90060-3

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe developmental expression of UDPgalactosexeramide galactosyltransferase (CGalT), an enyme marker of one myelinogenic activity in nervous tissue, was studied in cultured oligodendrocytes. The activity of CGalT in cultures followed a characteristic pattern of developmental changes. In the primary cultures these changes could be represented by a biphasic curve with a maximum of enzymatic activity at about the 25th day in culture. After purifying the oligodendrocytes from the primary cultures and replating them in culture dishes, similar developmental changes of CGalT were observed. In the subultures prepared from 20‐day‐old primary cultures the activity of CGalT per oligodendrocyte increased from 1.3 × 10−6nmol/hr on day 4 to 3.7 ×−6nmol/hr on day 21. Immunocytochemical studies with the antiserum against rat brain CGalT showed the presence of CGalT+oligodendrocytes after 7 days in the primary culture (earliest time studied), later on the number of CGalT+oligodendrocytes increased until 28 days (latest time examined). In the subcultures of purified oligodendrocytes the bulk of oligodendrocytes was stained by the anti‐CGalT antibodies after 15 days. These results suggest that the initial expression of CGalT in oligodendroglial cultures involves an increase of the number of CGalT+oligodendrocytes and of the amount of enzyme protein per cell.

ISSN:0736-5748    

DOI:10.1016/0736-5748(88)90061-5

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractPregnant Sprague‐Dawley rats were treated with 5 mg/kg body weight of phencyclidine (PCP) injected at 1 ml/kg subcutaneously on three consecutive days at four different stages of gestation. Within 10–30 min after treatment, dams showed some lack of motor coordination and became lethargic. On gestational day 21, all rats were killed by decapitation and brains were dissected and stored from mother and fetus for neurochemical analysis. PCP, dopamine and muscarinic cholinergic receptor binding was measured in membranes prepared from maternal and fetal whole brain. Neurotransmitter concentrations were also measured in the fetal brain homogenates. There was a significant decrease in PCP binding sites in fetal but not maternal brains after maternal PCP injection at gestational days 12–14, 15–17 and 18–20, but not at 9–11 days. Dopamine and muscarinic cholinergic receptor binding was not significantly altered in fetal or maternal brain when compared with vehicle control animals. The whole brain dopamine, 3,4‐dihydroxyphenylacetic acid, serotonin, and 5‐hydroxyindoleacetic acid concentrations did not show significant change in any group studied. These data indicate that gestational exposure to PCP decreases high affinity binding of PCP in term fetal brain at doses which do not alter maternal PCP receptor binding.

ISSN:0736-5748    

DOI:10.1016/0736-5748(88)90062-7

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractIt was previously reported that the acetylcholine receptor clusters and acetylcholinesterase appear on embryonic superior oblique muscle cells developingin vivowithout motor nerve contacts. The objective of this study was to examine whether some other components of neuromuscular junction also form on muscle cells developingin vivoin the absence of motor neurons. In the present study, postsynaptic specializations such as junctional folds, postsynaptic density and basal lamina were studied in normal and aneural muscles. The superior oblique muscle of duck embryos was made aneural by permanent destruction of trochlear motor neurons by cauterizing midbrain on embryonic day 7; 3 days before the motor neurons normally project their axons into the muscle. Normal and aneural muscles from embryonic days 10 to 25 were processed for electron microscopy. The results indicate that morphological specializations such as junction‐like folds, postsynaptic‐like density, and basal lamina also develop in the absence of motor neuron contacts. Whether the differentiation of specialized synaptic basal lamina is dependent on the presence of motor neurons was examined by utilizing a monoclonal antibody against heparan sulfate proteoglycan. Immunohistochemical studies indicate that specialized synaptic basal lamina differentiates in the absence of motor neurons. Thus, the mechanism of development of postsynaptic components of neuromuscular junction in this muscle is not dependent on motor neuron contacts. These results also suggest that the postsynaptic cell plays a more active role in synapse formation than previously realized. The results are discussed in relation to the control of synapse numbers by the postsynaptic cell.

ISSN:0736-5748    

DOI:10.1016/0736-5748(88)90063-9

出版商:Wiley    

年代:2003

数据来源: WILEY

ISSN:0736-5748    

DOI:10.1016/0736-5748(88)90064-0

出版商:Wiley    

年代:2003

数据来源: WILEY