ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Nociceptin/orphanin FQ (NC) and its receptor (OP4) have been implicated in pain transmission. The aim of the present study was to investigate the role of the NC/OP4system in stress-induced analgesia (SIA). The tail-withdrawal assay was performed in mice stressed by forced swimming in water at 15°C (high severity swims) or 32°C (low severity swims). High severity swims produced a naloxone-insensitive antinociceptive effect which was blocked by supraspinal NC (1 nmol). The selective OP4receptor antagonist, [Nphe1]NC(-13)NH2(30 nmol), was inactive by itself, but prevented the effect of NC. Low severity swims produced a milder analgesic effect that was partially antagonized by naloxone, completely blocked by NC and potentiated by [Nphe1]NC(-13)NH2. These findings confirm the anti-analgesic role of supraspinal NC and suggest that endogenous NC signaling counteracts the opioid component of SIA.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Repetitive tapping is used to investigate temporal perception, memory, and reproduction. Intertap intervals and their variability, arise from cognitive and motor processes during the task. We used a measure of readiness potential onset to determine motor component latency during the timed interval. Subjects performed a paced, two-handed tapping task at four target intervals (1.5–2.75 s). Overall latency of production increased with increasing ISI, as did variability across target interval, conforming to a generalized Weber's law. In contrast, average motor latency was roughly 0.5 s across ISI. This constant motor latency may also indicate constant variability attributable to motor processing.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Early life environmental manipulations have been shown to affect hippocampal-dependent learning, hippocampal volume and cerebral lateralization. In this study, we investigated the effects of neonatal stimulation on hippocampal volumetric asymmetry. Long-Evans hooded rats were exposed to a novel non-home environment 3 min daily for the first 3 weeks of life. Histological measures of the left and right hippocampus were made at 8 months of age. We found that neonatal novelty exposure resulted in a long-lasting change in hippocampal volumetric asymmetry. Specifically, this brief and transient early life stimulation increased the right hippocampal volumetric dominance at mid-adulthood.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Focal lesions of the visual cortex induce deafferentiation, excitotoxic cell death as well as functional reorganization in the surrounding tissue. The intracellular second messenger calcium is involved in a wide range of cellular responses including excitotoxicity and functional reorganization following cortical injuries. We investigated the intracellular calcium concentration [Ca2+]iin neurons of the visual cortex using fluorescence imaging of fura-2 signals in a slice preparation obtained from lesioned and sham-operated cortices. We observed an increase in resting and stimulus evoked [Ca2+]iin the surround of the lesion, which were mediated by NMDA and non-NMDA ionotropic glutamate receptors. This increase in [Ca2+]imight be an important factor for lesion-induced functional reorganization in the rat visual cortex.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Bacterial DNA and synthetic oligodeoxynucleotides (ODN) containing unmethylated CpG motifs stimulate cells of the immune system to secrete a variety of cytokines and chemokines. This function can be carried out by microglia and astrocytes in the CNS. To evaluate the effect of CpG ODN on microglia and astrocytes, purified cells were isolated and culturedin vitro. CpG ODN rapidly up-regulated their production of IL-1β, IL-6, IL-12, TNFα, MIP-1α and/or MIP-1β.In vivo, systemically administered CpG ODN up-regulated the expression of mRNA encoding cytokines and chemokines in normal mouse brain. These findings suggest that CpG ODN can directly activate immune cells of the CNS.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Light close to and in the near-infrared range has documented benefits for promoting wound healing in human and animals. However, mechanisms of its action on cells are poorly understood. We hypothesized that light treatment with a light-emitting diode array at 670 nm (LED) is therapeutic in stimulating cellular events involving increases in cytochrome oxidase activity. LED was administered to cultured primary neurons whose voltage-dependent sodium channels were blocked by tetrodotoxin. The down-regulation of cytochrome oxidase activity by TTX was reverted to control levels by LED. LED alone also up-regulated enzyme activity. Thus, the results are consistent with our hypothesis that LED has a stimulating effect on cytochrome oxidase in neurons, even when they have been functionally silenced by TTX.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

+/Lc Purkinje cells degenerate postnatally because of a gain-of-function mutation in the δ2 glutamate receptor (Grid2) that causes a constitutive Na+current leak. The effect of the resulting chronic depolarization on Purkinje cell metabolism was investigated by measuring levels of cytochrome oxidase (COX) activity in Purkinje cell dendrites using quantitative densitometry. Analysis of wild type controls and +/Lc mutants at P10, P15 and P25 showed that levels of COX activity were significantly increased above control levels by P15 and continued to increase through P25. The increase in COX activity is likely to reflect an increase in oxidative phosphorylation to accommodate the energy demands of removing excess Na+and Ca2+entering the Purkinje cells in response to the Grid2 leak current.

ISSN:0959-4965    

出版商:OVID    

年代:2001

数据来源: OVID