Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde (ICBS), Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos 2600 - anexo 90035-003, Porto Alegre, RS, Brazil.
Behav Brain Res. 2010 Jun 26;210(1):92-8. doi: 10.1016/j.bbr.2010.02.015. Epub 2010 Feb 13.
Neonatal cerebral hypoxia-ischemia (HI) is an important cause of neurological deficits. The Levine-Rice model of unilateral HI is a useful experimental tool, but the resulting brain damage is mainly restricted to one hemisphere. Since the rat presents morphological and biochemical asymmetries between brain hemispheres, behavioral outcome from this model is probably dependent on which hemisphere is damaged. We here investigated the effects of sex and lesioned hemisphere on the outcome of open field, plus maze, inhibitory avoidance and water maze tasks in adult rats previously submitted to neonatal unilateral HI. Females were more active than males in some of studied parameters and males presented better spatial learning. Hypoxia-ischemia caused spatial deficits independently of sex or damaged hemisphere. Right-HI increased locomotion only in males and caused working memory in females and on aversive learning in both males and females. Morphological analysis showed that right-HI animals presented greater reduction of ipsilateral striatum area, with females being more affected. Interestingly, males showed greater hippocampal volume. These results show that task performance and cerebral damage extension are lateralized and sex-dependent, and that the right hemisphere, irrespective of sex, is more vulnerable to neonatal cerebral hypoxia-ischemia.
新生儿脑缺氧缺血（HI）是神经功能缺损的一个重要原因。Levine-Rice 模型的单侧 HI 是一种有用的实验工具，但由此产生的脑损伤主要局限于一个半球。由于大鼠的大脑在两个半球之间存在形态和生化的不对称性，因此该模型的行为结果可能取决于损伤的是哪一侧半球。我们在这里研究了性别和损伤半球对先前经历过新生儿单侧 HI 的成年大鼠在旷场、加迷宫、抑制性回避和水迷宫任务中的影响。女性在一些研究参数中比男性更活跃，而男性的空间学习能力更好。缺氧缺血导致空间缺陷，与性别或损伤半球无关。右侧 HI 仅在雄性中增加运动，而在雌性中引起工作记忆，并在雄性和雌性中引起厌恶学习。形态学分析显示，右侧 HI 动物同侧纹状体区域的减少更为明显，而雌性受影响更大。有趣的是，雄性表现出更大的海马体积。这些结果表明，任务表现和脑损伤扩展是偏侧化和性别依赖性的，并且右侧半球，无论性别如何，都更容易受到新生儿脑缺氧缺血的影响。
