摘要:

Profilin and profilin mRNA concentrations were determined in the cerebellum of the developing rat. Profilin represented nearly 0.1% of total Triton-soluble protein both at birth and at the end of the developmental period. During brain maturation, the profilin concentration was regulated at the transcriptional level. A transient increase of profilin mRNA and profilin was observed at the end of the first postnatal week, a period of intense cell proliferation, neuritic outgrowth and synaptogenesis. We propose that profilin may act by forming, during the critical period of cerebellar development, a reserve pool of monomeric actin that can easily be mobilized in cell regions such as growth cones or synaptic junctions where filamentous actin is highly concentrated.

ISSN:0959-4965    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Incubation of a primary culture of rat striatal neurons with sodium nitroprusside (SNP), a known source of nitric oxide (NO), showed a concentration-dependent increase in cyclic GMP levels with an EC50value of 13.7 μM. Twenty-four hours following incubation with 10 μM SNP, striatal neurons underwent degeneration as assessed immunohistochemically and biochemically. In contrast, potassium ferricyanate at concentrations up to 1 mM had no effect on striatal neuron viability. These results indicate that SNP has neurotoxic actionsin-vitro, an effect that may involve NO as a second messenger.

ISSN:0959-4965    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Using fura-2 loaded neural tumour cells, SK-N-SH, we demonstrate that receptor-mediated activation of phosphoinositide hydrolysis not only causes the release of Ca2+from intracellular stores but also causes a concomitant influx of extracellular Ca2+. Thapsigargin (TG), a sesquiterpene lactone, causes a sustained elevation of intracellular Ca2+depletion of the inositol 1, 4, 5-trisphosphate-sensitive intracellular Ca2+stores. In the absence of extracellular Ca2+, the increase in intracellular Ca2+concentration ([Ca2+]i) was transient, suggesting that thapsigargin activates both intracellular mobilization and the influx of Ca2+from extracellular space. These results are consistent with the proposal that the depletion of the inositol 1, 4, 5-trisphosphate-sensitive intracellular Ca2+pool serves as a signal for Ca2+influx.

ISSN:0959-4965    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

To evaluate the role of G proteins in acetylcholine (ACh)-mediated signal transduction, a novel assay to measure [35S]GTPγS binding to rat striatal membranes was standardized. ACh and carbamylcholine (CCh) stimulated the high affinity [35S]GTPγS binding to striatal membranes by up to 45% in a concentration-dependent manner. A time course study revealed that 0.1 μM CCh stimulated [35S]GTPγS binding by 26% at 4 min and 20% at 15 min. CCh-stimulated [35S]GTPγS binding was inhibited by atropine, N-methylscopolamine and pirenze-pine. Oxotremorine (1 μM), a partial muscarinic agonist, maximally stimulated the binding to striatal membranes by only 25%.

ISSN:0959-4965    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

N-acetylaspartate (NAA) is one of the most prevalent compounds in the mammalian nervous system. As such, NAA largely contributes to the major peak on water-suppressed proton magnetic resonance spectra. Highly specific antibodies to NAA demonstrate that this compound is discretely localized in a substantial number of neurons throughout the extent of the rat CNS. N-acetylaspartylglutamate (NAAG) is a structurally related neuronal dipeptide which is less widely distributed than NAA. NAAG and NAA immunoreactivities were extensively colocalized in many brainstem areas, where NAAG containing neurons were more numerous than in forebrain structures.

ISSN:0959-4965    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Adult mouse MBP charge isomers (C1 or component 1, C2 or component 2, etc.) were purified from an acid soluble brain protein fraction by cation exchange chro-matography. They were characterized by their elution profiles, their migration rates in alkaline-urea gels and by SDS-PAGE. Mouse Cl and C2 were both 14 kD in size, while C3, C4 and C5 consisted of the 18.5, 17 and 14 kD isoforms. Comparison of mouse and human MBP charge isomers showed that they were similar in that they both showed extensive charge heterogeneity, but different in that mouse MBP charge isomers were more cationic than their human counterparts. Finally, a possible explanation for the presence of the 14 kD MBP isoform in mouse myelin was suggested.

ISSN:0959-4965    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The present data show that selective A2adenosine receptor antagonists tended to increase locomotor and rearing activities in mice confronted with a free exploratory test. These findings support the hypothesis that the behavioural effects of adenosine antagonists can be linked to their actions at adenosine A2receptors.

ISSN:0959-4965    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

We describe a strain of rats (Wistar-Furth) that is highly susceptible to the neurotoxic effects of kainic acid (KA) and presents a reliable and quantifiable (with low within-group variability) animal model of status epilepticus. Wistar-Furth rats are more sensitive and demonstrate a less variable convulsant response than Sprague-Dawley and Long-Evans rats when tested for total time in seizure activity, latency to onset of first seizure, latency to status epilepticus, seizure severity scores, and percentage exhibiting behavioral seizures and status epilepticus. Results suggest that significant heterogeneity exists in the rodent population with regard to neuronal sensitivity to an excitotoxic amino acid and indicate that strain differences are an important consideration in studies using KA.

ISSN:0959-4965    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Mumps virus caused a partially lytic infection in cultivated rat embryonic dorsal root ganglion neurons with a restricted formation of viral components. The neuronal degeneration was markedly enhanced by increasing the calcium concentration of the medium and could be almost totally inhibited by the dihydropyridine calcium channel antagonist nifedipine. The drug had no effect on a productive and completely lytic Sendai virus infection of the neurons. A previous neurophysiological study has shown that a reduced calcium influx occurs during the action potential early during the infection. The present study suggests a crucial role of calcium in neurodegeneration induced by certain viruses.

ISSN:0959-4965    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

In this present study, behavioral responses to a subcutaneous formalin test for pain are evaluated in rats that previously received an allograft of adrenal chromaffin tissue into arachnoid of the dorsal spinal cord and in control animals. In the group of rats with grafts, a significant basal analgesia, reversed by the opioid antagonist naloxone, is found. These findings suggest that the grafts secrete some substance that reduces the response to painful stimulation and whose action is blocked by naloxone.

ISSN:0959-4965    

出版商:OVID    

年代:1991

数据来源: OVID