Prusator D K, Greenwood-Van Meerveld B
Oklahoma Center for Neuroscience, University of Oklahoma Health Science Center, Oklahoma City, OK, USA.
Neurogastroenterol Motil. 2015 Jan;27(1):72-81. doi: 10.1111/nmo.12472. Epub 2014 Nov 14.
Evidence exists to suggest that early life stress (ELS), such as neglect or abuse has profound effects on the developing brain. The current study tests the hypothesis that ELS in the form of neonatal limited nesting (LN) may serve as a predisposing factor for the development of altered nociceptive processing and comorbid increases in anxiety-like behavior in adulthood.
Both male and female neonatal Sprague-Dawley rats were subjected to LN from postnatal day (PND) 2-9, while a control group was exposed to standard cage bedding. In adulthood, visceral sensitivity was assessed by quantifying a visceromotor behavioral response to graded isobaric pressures of colorectal distension. Hindpaw withdrawal thresholds in response to von Frey filaments were used to measure somatic sensitivity. Anxiety-like behavior was assessed in adult life using both the elevated plus maze and open field assay.
Early life stress in the form of neonatal LN induced visceral and somatic hypersensitivity in adult male rats and augmented anxiety-like behavior. However, in adult cycling females, neonatal LN did not alter nociceptive processing or lead to changes in the levels of anxiety-like behavior.
CONCLUSIONS & INFERENCES: Our findings suggest that in male rats the LN model is a novel tool to investigate the long-term consequences of adverse early life experience on adult health.
有证据表明，早期生活压力（ELS），如忽视或虐待，会对发育中的大脑产生深远影响。当前研究检验了这样一个假设，即新生儿有限筑巢（LN）形式的早期生活压力可能是成年后伤害性处理改变和焦虑样行为共病性增加的一个诱发因素。
雄性和雌性新生斯普拉格-道利大鼠在出生后第2天至第9天接受有限筑巢处理，而对照组则接触标准笼内垫料。成年后，通过量化对结肠扩张的分级等压压力的内脏运动行为反应来评估内脏敏感性。使用对von Frey细丝的后爪撤离阈值来测量躯体敏感性。在成年期使用高架十字迷宫和旷场试验来评估焦虑样行为。
新生儿有限筑巢形式的早期生活压力在成年雄性大鼠中诱发了内脏和躯体超敏反应，并加剧了焦虑样行为。然而，在成年的发情期雌性大鼠中，新生儿有限筑巢并未改变伤害性处理，也未导致焦虑样行为水平的变化。
我们的研究结果表明，在雄性大鼠中，有限筑巢模型是一种用于研究早期生活不良经历对成年健康长期影响的新工具。
