Smith Amanda L, Garbus Haley, Rosenkrantz Ted S, Fitch Roslyn Holly
Department of Psychology, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT 06269, USA.
Department of Pediatrics, University of Connecticut School of Medicine, 263 Farmington Avenue, Farmington, CT 06030, USA.
Brain Sci. 2015 May 22;5(2):220-40. doi: 10.3390/brainsci5020220.
Neonatal hypoxia ischemia (HI; reduced oxygen and/or blood flow to the brain) can cause various degrees of tissue damage, as well as subsequent cognitive/behavioral deficits such as motor, learning/memory, and auditory impairments. These outcomes frequently result from cardiovascular and/or respiratory events observed in premature infants. Data suggests that there is a sex difference in HI outcome, with males being more adversely affected relative to comparably injured females. Brain/body temperature may play a role in modulating the severity of an HI insult, with hypothermia during an insult yielding more favorable anatomical and behavioral outcomes. The current study utilized a postnatal day (P) 7 rodent model of HI injury to assess the effect of temperature modulation during injury in each sex. We hypothesized that female P7 rats would benefit more from lowered body temperatures as compared to male P7 rats. We assessed all subjects on rota-rod, auditory discrimination, and spatial/non-spatial maze tasks. Our results revealed a significant benefit of temperature reduction in HI females as measured by most of the employed behavioral tasks. However, HI males benefitted from temperature reduction as measured on auditory and non-spatial tasks. Our data suggest that temperature reduction protects both sexes from the deleterious effects of HI injury, but task and sex specific patterns of relative efficacy are seen.
新生儿缺氧缺血（HI；大脑的氧气和/或血流减少）可导致不同程度的组织损伤，以及随后出现的认知/行为缺陷，如运动、学习/记忆和听觉障碍。这些后果通常源于早产儿中观察到的心血管和/或呼吸事件。数据表明，HI的结果存在性别差异，相对于同等受伤的女性，男性受到的负面影响更大。脑/体温可能在调节HI损伤的严重程度中发挥作用，损伤期间的低温会产生更有利的解剖学和行为学结果。本研究利用出生后第7天（P7）的啮齿动物HI损伤模型，评估损伤期间温度调节对每种性别的影响。我们假设，与雄性P7大鼠相比，雌性P7大鼠会从体温降低中获益更多。我们在转棒试验、听觉辨别试验以及空间/非空间迷宫任务中对所有受试对象进行了评估。我们的结果显示，通过大多数所采用的行为任务测量，体温降低对HI雌性大鼠有显著益处。然而，通过听觉和非空间任务测量，HI雄性大鼠从体温降低中获益。我们的数据表明，体温降低可保护两性免受HI损伤的有害影响，但存在任务和性别特异性的相对疗效模式。
