1 Laboratory of Molecular and Cellular Biology (LABIM), Postgraduate Programme of Health Sciences, Department of Health Sciences, University of Southern Santa Catarina, Criciúma, SC, Brazil.
2 Laboratory of Neuroscience, Postgraduate Programme of Health Sciences, Department of Health Sciences, University of Southern Santa Catarina, Criciúma, SC, Brazil.
Acta Neuropsychiatr. 2014 Jun;26(3):161-9. doi: 10.1017/neu.2013.48.
This study investigated the influence of ageing - in particular the decrease of gonadal hormone levels during the ageing process - on the memory and the levels of DNA damage in the hippocampus of female rats.
Three groups of female Wistar rats were investigated: Group I consisted of non-ovariectomised, adult animals (6 months old); Group II consisted of non-ovariectomised, aged animals (18 months old); and Group III consisted of ovariectomised, aged animals (18 months old). The memory of the animals in these groups was examined via novel object recognition and inhibitory avoidance tests. The hippocampus tissue samples of all animals were obtained via biopsy and used to quantify the DNA damage using a Comet Assay.
According to our findings, the process of ageing results in a change during the behavioural tests. To prevent genotoxic damage to the hippocampus caused by the ageing process, lowered hormone levels seem to be part of a protective biochemical mechanism in the body of rats. Animals that were previously submitted to an ovariectomy adapted better to these lower levels of hormones.
Our results indicate that ovariectomy can provide beneficial long-term effects on the memory. However, this could be specific to the kind of memory examined, as the aversive memory deficits caused by ageing were not affected by ovariectomy.
本研究旨在探讨衰老过程中（尤其是性腺激素水平下降）对雌性大鼠海马体记忆力和 DNA 损伤水平的影响。
本研究调查了三组雌性 Wistar 大鼠：I 组为未卵巢切除的成年动物（6 个月龄）；II 组为未卵巢切除的老年动物（18 个月龄）；III 组为卵巢切除的老年动物（18 个月龄）。通过新物体识别和抑制回避测试来检查这些动物的记忆力。通过活检获取所有动物的海马组织样本，并使用彗星试验来定量 DNA 损伤。
根据我们的研究结果，衰老过程会导致行为测试中的变化。为了防止衰老过程中对海马体造成的遗传毒性损伤，降低激素水平似乎是大鼠体内一种保护生物化学机制的一部分。先前接受过卵巢切除术的动物对这些较低水平的激素适应得更好。
我们的研究结果表明，卵巢切除术对记忆力可能有有益的长期影响。然而，这可能是特定于所检查的记忆类型，因为衰老引起的厌恶记忆缺陷不受卵巢切除术的影响。
