暴露于太空银河宇宙辐射是深空任务的主要考虑因素。虽然空间辐射对神经系统的影响尚不完全清楚,动物模型的研究表明,暴露于电离辐射会导致神经元损伤,并导致下游认知和行为缺陷。认知健康的影响使人类和任务处于危险之中,随着即将到来的阿尔特弥斯任务,女性船员将扮演重要角色,对雄性和雌性啮齿动物对太空辐射的神经和性能反应进行深入的批判性分析至关重要。这里,我们测试了模拟银河宇宙辐射(GCRSim)暴露破坏小鼠物种典型行为的假设,包括挖洞,饲养,梳理,以及依赖于海马和内侧前额叶皮层电路的筑巢。行为包括一个非常好的完整的整个动物的生物学表现,告知整体的神经和生理状态,揭示功能损害。我们对暴露于5、15或50cGy5-离子GCRSim(H,Si,他,O,Fe)在NASA空间辐射实验室(NSRL)。在暴露后72小时(急性)和91天(延迟)评估行为表现。具体来说,物种典型的行为模式,包括挖洞,饲养,分析了梳理和筑巢。神经评分测试电池(自发活动,本体感受,vibrissae触摸,肢体对称,横向车削,前肢伸展,和攀爬)在急性时间点进行,以调查辐射暴露后的早期感觉运动缺陷。筑巢建筑,衡量啮齿动物的神经和组织功能,使用五个阶段的Likert量表“Deacon”评分进行评估,评分范围从1(雀巢未触及的低分)到5(雀巢完全切碎并成形为巢的高分)。在15cGy暴露后,相对于男性,在女性相对于男性的物种典型行为方面观察到了不同的急性反应,而在50cGy暴露后,在女性修饰中观察到了延迟反应。在筑巢的两个时间点均观察到显着的性别差异。通过神经评分没有观察到感觉运动行为的缺陷。这项研究揭示了微妙的,性二态GCRSim暴露对小鼠行为的影响。我们的分析提供了对典型物种的GCR剂量效应的更清晰的理解,放射后急性和延迟时间范围内的感觉运动和组织行为,从而为识别潜在的细胞和分子事件奠定了基础。
Exposure to space galactic cosmic radiation is a principal consideration for deep space missions. While the effects of space irradiation on the nervous system are not fully known, studies in animal models have shown that exposure to ionizing radiation can cause neuronal damage and lead to downstream cognitive and behavioral deficits. Cognitive health implications put humans and missions at risk, and with the upcoming Artemis missions in which female crew will play a major role, advance critical analysis of the neurological and performance responses of male and female rodents to space radiation is vital. Here, we tested the hypothesis that simulated Galactic Cosmic Radiation (GCRSim) exposure disrupts species-typical behavior in mice, including burrowing, rearing, grooming, and nest-building that depend upon hippocampal and medial prefrontal cortex circuitry. Behavior comprises a remarkably well-integrated representation of the biology of the whole animal that informs overall neural and physiological status, revealing functional impairment. We conducted a systematic dose-response analysis of mature (6-month-old) male and female mice exposed to either 5, 15, or 50 cGy 5-ion GCRSim (H, Si, He, O, Fe) at the NASA Space Radiation Laboratory (NSRL). Behavioral performance was evaluated at 72 h (acute) and 91-days (delayed) postradiation exposure. Specifically, species-typical behavior patterns comprising burrowing, rearing, and grooming as well as nest building were analyzed. A Neuroscore test battery (spontaneous activity, proprioception, vibrissae touch, limb symmetry, lateral turning, forelimb outstretching, and climbing) was performed at the acute timepoint to investigate early sensorimotor deficits postirradiation exposure. Nest construction, a measure of neurological and organizational function in rodents, was evaluated using a five-stage Likert scale \'Deacon\' score that ranged from 1 (a low score where the Nestlet is untouched) to 5 (a high score where the Nestlet is completely shredded and shaped into a nest). Differential acute responses were observed in females relative to males with respect to species-typical behavior following 15 cGy exposure while delayed responses were observed in female grooming following 50 cGy exposure. Significant sex differences were observed at both timepoints in nest building. No deficits in sensorimotor behavior were observed via the Neuroscore. This study revealed subtle, sexually dimorphic GCRSim exposure effects on mouse behavior. Our analysis provides a clearer understanding of GCR dose effects on species typical, sensorimotor and organizational behaviors at acute and delayed timeframes postirradiation, thereby setting the stage for the identification of underlying cellular and molecular events.