ISSN:0360-4012    

DOI:10.1002/jnr.490060502

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractA solid phase radioimmunoassay is described which employs125I‐protein‐A to detect the presence of antibodies against a panel of cellular and soluble central nervous system (CNS) specific antigens coated onto polyvinylchloride Microtiter plates. Serum antibodies from rabbits immunized against myelin, myelin basic protein (MBP), glial acidic fibrillary protein (GFAP), astroglioma cells, and cerebellar cells were easily detected, and high specificity for each antiserum and antigen was also demonstrable. The assay is applicable to cerebrospinal fluid (CSF) from patients with neurological diseases to detect antibodies against CNS‐specific antigens. The assay should be useful for examining cell lines derived from CNS tissue for the presence of brain pro

ISSN:0360-4012    

DOI:10.1002/jnr.490060503

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractMet 5‐enkephalin blocks the active transport of GABA across plasma membranes of rabbit Deiters' neurons prepared by microdissection. Such an effect is receptor‐mediated, being reversed by the antagonist Naloxone.This result shows that Deiters' neurons bear enkephalin receptors, and suggests a hypothesis on the mechanism of enkephalin‐mediated neuronal inhib

ISSN:0360-4012    

DOI:10.1002/jnr.490060504

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractThe contribution of glucose carbon to the biosynthesis of cholesterol and phospholipids in distinct brain regions was studied quantitatively in the adult male rat. Rates of flow of glucose carbon into the lipids in vivo were calculated from two measurements: the curve representing the decrease in plasma14C‐glucose with time and the specific activity of the cerebral lipid 180 minutes after a rapid intravenous injection of a tracer dose of D–U14C‐glucose. The following brain regions were studied: cerebral cortex, hypothalamus, medulla, and corpus callosum and cerebellum. The values for carbon flow into phospholipids were significantly higher in the hypothalamus than in the whole brain, whereas small, but insignificant, regional differences were found for carbon flow into cholesterol. The conversion of U‐14C‐glucose to individual phospholipids of both hypothalamus and cerebral cortex was further investigated in vitro in order to establish whether the higher rate of carbon flow into hypothalamic phospholipids resulted from enhanced synthesis of a particular phospholipid. In agreement with the results obtained in vivo, the rate of incorporation of14C into total phospholipids was 60% higher in hypothalamic tissue. The results indicate that the higher rate of carbon flow into hypothalamic phospholipids might be attributed to enhanced incorporation of glucose carbon to phosphatidyl‐choline and phosphatidyl‐ethanolamine following a faster conversion of glucose to glycerol in this

ISSN:0360-4012    

DOI:10.1002/jnr.490060505

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractThe distribution of presynaptic markers for cholinergic and GABAergic neurons in the various layers of the lateral neocortex was determined with a techique in which sections of increasing depth horizontal to the pial surface were obtained on a frozen‐stage microtome and analyzed for the markers. The specific activities of choline acetyltransferase and acetylcholinesterase had an uneven distribution in the cortex with lowest levels of activity associated with lamina II and III, whereas glutamate decarboxylase activity was highest in lamina II, III, and IV. Fetally‐induced hypoplasia of the cortex resulted in an enrichment in both choline acetyltransferase and acetylcholinesterase activity in all layers with no significant change in the activity of glutamate decarboxylase. Lesion of the nucleus basalis–cortical cholinergic pathway resulted in marked reductions in the activities of acetylcholinesterase and choline acetyltranferase in all cortical layers and an elimination of the uneven distribution of these markers within the cortex. These results provide further evidence that acetylcholinesterase activity is specifically associated with cortical cholinergic afferents and support the existence of cortical intrinsic cholinergic ne

ISSN:0360-4012    

DOI:10.1002/jnr.490060506

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractThe thyroid hormones triiodothyronine (T3) and L‐thyroxine appear to enhance regeneration in the peripheral and central nervous system (CNS). The following experiments examine possible metabolic substrates for the action of T3on the adult rat CNS after spinal hemisection. The protein incorporation of (3H)lysine after a left spinal hemisection (T2) or control operations was examined 1, 3, 7, and 14 days postoperation. Triiodothyronine (1 μg/kg body weight in a bicarbonate buffer) was injected daily for the postoperation or equivalent time period. One hour prior to decapitation, animals were given a subcutaneous injection of 200 μCi of (3H)lysine. Samples of brain and spinal cord were dissolved, and the radioactivity of acid‐precipitable protein and acid‐soluble fractions were determined by scintillation counting. T3treatment influenced the general levels of incorporation of all treated groups over all days postoperation. Specific effects were observed in spinal hemisected T3‐treated animals. A significant hemispheric (P<0.05) asymmetry was present at 3 days postoperation with the right somatomotor cortex higher in protein radioactivity than the left. In spinal cord, the area of the lesion and areas just caudal to the lesion were higher in (3H)lysine incorporation in T3‐treated rats relative to controls. T3effects appear to involve an increased sensitivity of the cells of the injured nervous system to

ISSN:0360-4012    

DOI:10.1002/jnr.490060507

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractTyrosine hydroxylase activity was measured in the region of locus coeruleus, cerebellum, cervical spinal cord, lumbar sympathetic ganglia, and iris throughout most of the life span of the chicken (8 days of incubation to 5 years) to compare developmental trends in tyrosine hydroxylase activity in noradrenergic cell bodies and in axon terminals in both the central and peripheral nervous system. Fluorescence histochemistry and retrograde transport of horseradish peroxidase were used to characterize further the coeruleo‐cerebellar projections. Tyrosine hydroxylase activity was detected in the cerebellum as early as 8 days of incubation, which is the earliest stage so far reported. The greatest increase in total tyrosine hydroxylase activity in the region of the locus coeruleus and cerebellum occurred during the embryonic period. There was a more pronounced increase in the cerebellum than in the locus coeruleus region. This is in contrast to the cervical spinal cord where tyrosine hydroxylase activity increased at approximately the same rate during the embryonic and post‐hatching periods. Moreover, the cerebellum and cervical spinal cord, two locus coeruleus target sites, displayed different trends in tyrosine hydroxylase activity throughout development and aging.In both structures examined in the peripheral nervous system, the greatest increase in total tyrosine hydroxylase activity occurred during the post‐hatching period, with a greater rise in the cell bodies of the lumbar sympathetic ganglia than in the noradrenergic terminals of the iris. In both the central and peripheral nervous system, total tyrosine hydroxylase activity continued to increase in noradrenergic terminals long after hatching reaching the highest levels at 7 months when the chicken is considered fully mature. During aging, 16 months to 5 years, there was a greater decrease in total tyrosine hydroxylase activity in the terminals of noradrenergic neurons than in the cell bodies in both the central and peripheral nervous system, a phenomenon that was more marked in the peripheral nervous system than in the

ISSN:0360-4012    

DOI:10.1002/jnr.490060508

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractMouse brain astrocytes from primary cultures were found to contain both α1and α2adrenergic receptors.3H WB 4101 labeled one category of binding site (KD=1.5±0.39 nM, Bmax =64±7.9 fmoles/mg protein) with typical α1adrenergic specificity (WB 4101>prazosin>yohimbine). The density of α1adrenergic receptors was 2–3 times higher in mouse cerebral cortex than in glial cells.Like rat brain [U'Pritchard et al, 1979; Rouot et al, 1980], mouse glial cells were found to contain two categories of3H clonidine binding sites: high affinity sites, which were identical to the high but not to the low affinity sites found in rat brain, since (1) they displayed the same affinity for3H clonidine (KD=1.2±0.13 nM, n=4) and the same typical α2adrenergic specificity (yohimbine>WB 4101>prazosin); (2) the dissociation rate constant for clonidine binding was equal to 0.06 min−1, a value close to that found previously for the high affinity3H clonidine binding sites in rat brain (0.05 min−1); and (3) divalent cations augmented and guanyl nucleotides reduced3H clonidine binding as in rat brain. Na+decreased3H clonidine binding in a complex manner.The number of high affinity sites in glial cells (52 ±9.4 fmoles/mg protein, n=4) was half the number found in mouse cerebral cortex (98 fmoles/mg protein). Low affinity3H clonidine binding sites (KD=81±18 nM, Bmax=96±5.8 fmoles/mg protein, n=3) were not fully characterized.In conclusion, glial cells contained the same α adrenergic receptors as those described in brain, but their physiological function

ISSN:0360-4012    

DOI:10.1002/jnr.490060509

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractTwo pools of seven brains each from adult Swiss‐Webster mice were homogenized, and supernatants were collected for bioassay. PC‐12 cells were placed in a bioassay plate at time zero, at a concentration of 104cells per well, and primed for 48 hours in a medium containing 50 ng/ml of mNGF. The PC‐12 cell bioassay for neurite outgrowth was conducted after primed cells were exposed to an NGF‐free medium for 24 hours. Suitable controls for serum toxicity and cell viability were established. The sensitivity of the bioassay approximates 100 pg NGF/ml. The results showed 80–100% neurite outgrowth in wells exposed to brain pool supernatant (BPS) alone, and control level outgrowth (3–8%) in wells containing BPS and specific anti‐β‐NGF antibody. Therefore, the brains of Swiss‐Webster adult mice contain an NGF‐like substance which promotes neurite outgrowth in PC‐12 cells. The substance probably is NGF itself, since the effect is blocked by

ISSN:0360-4012    

DOI:10.1002/jnr.490060510

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractCerebral hemispheres of 14‐ to 15‐day‐old mouse embryos were dissociated mechanically into single cells and cultured in polylysine‐coated plastic flasks. The succession of changes and the identification of cell populations have been studied by transmission electron microscopy (TEM). Four distinct cell types can be clearly defined. Neuroblasts, oligodendroblasts, and astroblasts were used to denote embryonic states of neurons, oligodendrocytes, and astrocytes. Cell populations were: (1) neuroblasts; (2) astroblasts, either growing on the surface of the flasks and forming a basal layer of epithelioid cells or scattered at the surface of the bed layer; (3) oligodendroblasts, characterized by a high nucleocytoplasmic ratio and resting on top of the bed layer; (4) macrophages. Incorporation of [3H]thymidine into cells at different days in culture (DIC) delineated at least three periods of DNA synthesis (from 1 to 6, from 10 to 20, and from 25 to 60 DIC). High cell RNA/DNA and protein/DNA ratios indicated an increase in the cytoplasmic mass. Guanylate cyclase (EC 4.6.1.2; GC) and adenylate cyclase (EC 4.6.1.1; AC) activities and the ratio AC/GC also agreed with the existence of different periods in culture, but the yin yang hypothesis (postulated by Goldberg et al, 1975) was only partially confirmed. Concerning membrane constituents, the evolution of the pattern of the major gangliosides showed a phase from 1 to 20 DIC which was characterized during the first half of this period by a high percentage of tri‐ and tetra‐sialogangliosides, thereby confirming the presence of well differentiated neurons. Choline acetyltransferase (EC 2.3.1.6; ChAc), acetylcholinesterase (EC 3.1.1.7; AChE), and [3H]muscimol binding (indicative of GABA‐receptors) supported this conclusion. Another phase from 20 to 60 DIC showed a relatively higher content of GM3 and GD3 of the disialogangliosides GD1a and GD1b. These data favor a glial origin of the cells, also demonstrated by TEM and by immunohistochemistry with anti‐glial fibrillary acidic protein (anti‐GFAP) and anti‐carbonic anhydrase isoenzyme II (anti‐CAII; EC 4.2.1.1) sera.Ultrastructural, biochemical, and immunohistochemical data are in agreement with the existence of successive and different periods of cell proliferation and differentiation which have been defined as: (1) mainly neuronal from 1 to 12 DIC; (2) astroglial and oligodendroglial between 10 and 20 DIC, and (3) possibly microglial from 25 to 40 DIC. This surface‐adhering primary culture system should significantly enhance efforts to examine the roles played by hormones or other effectors in the re

ISSN:0360-4012    

DOI:10.1002/jnr.490060511

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY