Alteration of expression levels of neuronal nitric oxide synthase and haem oxygenase-2 messenger RNA in the hippocampi and cortices of young adult and aged cognitively unimpaired and impaired Long-Evans rats

被引：40

作者：

Law, A

Doré, S

Blackshaw, S

Gauthier, S

Quirion, R ^{[1
]}

机构：

[1] McGill Univ, Dept Neurol & Neurosurg, Montreal, PQ H3A 2B4, Canada

[2] McGill Univ, Dept Psychiat, Montreal, PQ H3A 2B4, Canada

[3] Douglas Hosp, Res Ctr, Verdun, PQ H4H 1R3, Canada

[4] McGill Ctr Studies Ageing, Verdun, PQ H4H 1R3, Canada

[5] Johns Hopkins Univ, Dept Neurosci, Baltimore, MD 21205 USA

[6] Johns Hopkins Univ, Dept Anesthesiol & Crit Care Med, Baltimore, MD 21205 USA

来源：

NEUROSCIENCE | 2000年 / 100卷 / 04期

基金：

英国医学研究理事会;

关键词：

ageing; carbon monoxide; cognitive impairment; in situ hybridization; Morris water maze behavioural task;

D O I：

10.1016/S0306-4522(00)00316-X

中图分类号：

Q189 [神经科学];

学科分类号：

071006 ;

摘要：

Neuronal nitric oxide synthase and haem oxygenase-2 are postulated to be important enzymes involved in neuronal transmission and modulation of free radical levels in neurons. Hippocampal and cortical neuronal nitric oxide synthase and haem oxygenase-2 expressions were compared in young adult (6 months) and aged (24-26 months) Long-Evans rats. Aged rats were assigned as either cognitively unimpaired or impaired based on their performances in the Morris water maze behavioural task. In situ hybridization revealed increased neuronal nitric oxide synthase messenger RNA levels in selected regions of the hippocampi and cortices of aged rats. Moreover, aged cognitively impaired animals showed significantly higher neuronal nitric oxide synthase messenger RNA expression than aged cognitively unimpaired animals in several brain regions. For haem oxygenase-2 mRNA expressions, both young and aged cognitively impaired rats showed increased expressions in hippocampi compared with aged cognitively unimpaired rats, while no difference was found in cortices between all three animal groups. The increase in neuronal nitric oxide synthase messenger RNA expression levels in the aged animals may be related to increased free radical production occurring in ageing. Alternatively, elevated neuronal nitric oxide synthase and haem oxygenase-2 messenger RNA expressions may represent compensatory responses to oxidative stress and age-related changes in neuronal functions. Regarding cognitive status, aged cognitively impaired rats showed significant spatial memory deficits relative to young and aged cognitively unimpaired rats. Our data suggest a correlation between age-related cognitive impairment and change in messenger RNA expressions for the neuronal nitric oxide synthase and haem oxygenase-2 systems in brain areas implicated in learning and memory processes. (C) 2000 IBRO. Published by Elsevier Science Ltd. All rights reserved.

引用

页码：769 / 775

页数：7

共 68 条

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