ISSN:0959-4965    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

NEURONAL interferon-γ (N-IFN-γ), recently isolated from the nervous system, has a molecular weight distinct from that of lymphocyte-derived IFN-γ, but crossreacts immunologically and shares certain bioactivities with this cytokine. In the rat brain N-IFN-γ-immunoreactive perikarya were concentrated in the hypothalamic tuberomammillary nuclei; some immunostained neurones were also detected in the dorsal pontine tegmentum. Immunopositive nerve fibres were profusely distributed through the periventricular hypothalamus and midline thalamus. Scattered fibres occurred diffusely through the brain, ramified in the subpial layer and also surrounded intrathecal vessels. A dense concentration of puncta was detected in the suprachiasmatic nuclei and in the molecular layer of the hippocampal dentate gyrus. A role of N-IFN-γ in immunological reactions and in modulation of selective brain functions is suggested.

ISSN:0959-4965    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

(S)-BROMOHOMOIBOTENIC acid [(S)-BrHIbo] stereoselectively antagonized glutamate-stimulated phosphoinositide (PI) hydrolysis in baby hamster kidney (BHK) cells expressing mGluRla in a competitive manner with an IC50of 250 μM. However, (S)-BrHIbo did not inhibit (1S,3R)-1-aminocyclopentane-l,3-dicarboxylic acid [(1S,3R)-ACPD]-induced PI hydrolysis in rat hippocampal slices. (S)- or (R)-BrHIbo did not show any effects on forskolin-stimulated cAMP-formation in BHK cells expressing mGluR2 or mGluR4 but did displace [3H]2-amino-4-phosphonobutyrate ([3H]AP4) binding from rat corticalmembranes with high affinities (IC50= 1.0 μM and 1.1 μM, respectively). These data suggest that (S)-BrHIbo may interact with multiple PI-coupled glutamate receptors, however, at concentrations that are several fold higher than for displacement of [3H]AP4 binding from rat cortical membranes.

ISSN:0959-4965    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

STREPROZOTOCIN diabetes and extracerebral insulin affect acetyl-CoA and acetylcholine metabolism in the brain. In the present study we have shown that pyruvate utilization, acetyl-CoA content and ACh synthesis in nerve terminals from diabetic rats were 45, 30 and 50%, respectively, higher than that in healthy animals. Treatment with insulin normalized pyruvate utilization and acetylcholine synthesis but did not decrease the acetyl-CoA level. 3-Hydroxybutyrate did not affect acetyl-CoA and acetylcholine metabolism in control rats. However, in diabetic animals, 3-hydroxybutyrate significantly increased supply of acetyl-CoA for acetylcholine synthesis. These data provide evidence that increased provision of acetyl-CoA is prerequisite for activation of acetylcholine synthesis in diabetic brain.

ISSN:0959-4965    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

THE distribution of neuronal nitric oxide synthase (NOS) in the chicken brain was investigated by immunocytochemistry. Strongly stained neurones were concentrated in the paleostriatum augmentatum, lobus parolfactorius, ventral pallidum, olfactory tubercle, parts of the neostriatum, mesencephalic reticular formation and locus coeruleus. Cells in these areas have previously been shown to stain for NADPH-diaphorase, a histochemical activity associated with NOS. However, various structures which NADPH-diaphorase staining has suggested to contain NOS were not immunoreactive: these included the glomeruli of the olfactory bulb, magnocellular preoptic neurones, the median eminence, subcommissural organ and mesencephalic trigeminal neurones. NOS was sparsely present in the hyperstriatum ventrale, providing evidence against the involvement of nitric oxide in certain forms of learning and memory processes known to occur in this region.

ISSN:0959-4965    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

β-AMYLOID peptides are neurotoxic when applied to primary cultures of hippocampal neurones from the embryonic rat. This neurotoxic effect can be inhibited completely by certain disazo dyestuffs. The most potent of these are Congo Red and Congo Rubin, whilst Direct Garnet and sodium 4-aminonaphthalene-1-sulphonate are inactive. Congo Red also inhibits the neurotoxic effects of the human pancreatic amyloidogenic peptide amylin. It is postulated that these dyes, by interacting with the β-pleated sheet structure of amyloidogenic peptides, prevent aggregation and hence neurotoxity.

ISSN:0959-4965    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

NERVE growth factor promotes survival and differentiation of selected groups of neurones through long-term adaptive changes in cell function. While production of this neurotrophin in target cells in hippocampus is regulated in part by afferent glutamate neuronal input, we report now for the first time that nerve growth factor has a direct potentiating effect on spontaneous and depolarizationevoked release of glutamate from hippocampal nerve endings, accompanied by an increase in the excitatory postsynaptic potential of CA1 neurones. This correlated with increased incorporation of [32P]phosphate into synapsin I. Reciprocal positive feedback between production of trophic factors in target cells by neurotransmitter released from afferent neuronal inputs and the modulation of presynaptic neurotransmitter release by target-derived trophic factors provides a novel mechanism for shortterm control over synaptic communication.

ISSN:0959-4965    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

THE characteristics of glycinergic inhibitory postsynaptic currents (IPSCs) in sympathetic preganglionic neurons (SPNs) of neonatal rats were studied by whole-cell recordings in transverse spinal cord slices. In relation to postnatal age, the decay time constants of these currents decreased without a comparable effect on their rise time. This may result from α-subunit switching of the glycine receptor and/or increased glycine uptake during this period of postnatal life. The kinetics of glycinergic IPSCs were also temperature- and voltage-dependent. Whereas, compared with room temperature, rise and decay of the events were faster at more physiological temperature, only the decay increased upon depolarization. Visual identification of SPNs was confirmed by intracellular staining and comparison with retrogradely labeled SPNs.

ISSN:0959-4965    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

GLUTAMATE receptor activation induces an extracellular alkalinization in rodent hippocampus. We studied its Ca2+dependence and pharmacology in hippocampal slices. Glutamate-evoked alkaline shirts were blocked by 0 Ca2+saline. Alkalinizations Induced by AMPA (α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid) and NMDA (N-methyl-D-aspartate) were abolished by 20 μuM CNQX (6-cyano-7-nitro-nitroquinoxaline-2,3-dione) and 50 μM APV (DL-2-amino-5-phosphonovalerate), respectively. The AMPA- and NMDA-evoked alkaline shifts were blocked by 0 Ca2+, however, AMPA-induced [K+]0, elevation was unaffected. These data suggest that the glutamate receptor-channel does not mediate H+influx, and support a role for Ca2+-H+exchange.

ISSN:0959-4965    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

THIS study was undertaken to evaluate the short-term effects of glucocorticoid on the morphological characteristics of cultured rat dentate gyrus (DG) cells using immonocytochemistry for a cytoskeletal protein, microtubule-associated protein 2 (MAP2). A selective cell culture system of DG neurones was successfully established. Synthetic glucocorticoid, dexamethasone (DEX) increased the total length of immunoreactive (IR) processes of the DG neurones in a dose-dependent manner. DEX also increased the ratio of multipolar neurones with more than three processes. The area of cell body of immunoreactive processes increased with 5 μM DEX treatment. Our results suggest that cytological features of DG cells are strongly influenced by the action of glucocorticoid.

ISSN:0959-4965    

出版商:OVID    

年代:1994

数据来源: OVID