HOUSING ENRICHMENT AND EXPERIMENTAL MANIPULATION

本项目的长期目标是采用最先进的方法，系统地研究饲养和普通饲养对大鼠正常心血管和内分泌生理的影响。预计研究结果将极大地帮助机构动物护理和使用委员会确定哪些程序可以或不可以在啮齿动物居住区进行，以及丰富的住房环境是否能显着减少啮齿动物的压力。具体的目的是：(1)评估住宅环境对大鼠痛苦（或缺乏痛苦）的不同程度的丰富程度；(2)评估正在进行普通饲养或实验程序或“目睹”这些程序在其他动物身上进行的动物的痛苦程度。这些研究将在3个月、6个月或12个月大的雄性和雌性大鼠身上进行，这些大鼠来自商业供应商提供的四种常用的远交种。动物将被“仪器化”，用无线电遥测发射机连续监测动脉血压和心率，或用长期留置静脉导管连续采集血液样本，以测定血浆中与应激相关的激素水平（儿茶酚胺、皮质酮和催乳素）。还将监测其他变量（体重增加、食物和水的消耗以及发情周期），以衡量大鼠的生理状态。要评估的住房条件是：隔离（单人）住房，成对（双人）住房，带有“咀嚼”和“攀爬/躲藏”“玩具”的隔离住房，以及每天有短时间进入非常丰富的环境的隔离住房。对环境住房条件的适应性也将进行评估。将使动物接触或目睹对其他动物进行的常见饲养和实验操作将包括：转移到新笼子，手约束和s.c.注射，在啮齿动物约束器中放置一段时间并进行尾静脉注射，目睹其他动物的斩首和见证从其他动物身上摘取组织。虽然这个项目是描述性的，而不是假设驱动的，但它应该提供非常实用和重要的结果，可以供当地IACUCs审查动物协议时使用，也可以供PHS、AAALAC、ILAR和USDA等国家组织在该领域颁布要求、指导方针和法规时使用。

The long-range goal of this project is to conduct systematic studies on the effects of housing enrichment and common husbandry and experimental procedures on the normal cardiovascular and endocrine physiology of rats using state-of-the-art methodologies. It is anticipated that the results will greatly assist Institutional Animal Care and Use Committees in their determination of what procedures can or cannot be conducted in rodent housing areas and whether or not enrichment of the housing environment significantly reduces stress in rodents. The specific aims are: (1) To evaluate several levels of enrichment of the housing environment on distress (or lack of distress) in rats and (2) To evaluate the level of distress in animals undergoing common husbandry or experimental procedures or "witnessing" these procedures being done on other animals. These studies will be conducted on 3-, 6- or 12-month old male and female rats of four commonly used outbred strains obtained from commercial vendors. Animals will be "instrumented" with a radio-telemetry transmitter to continuously monitor arterial blood pressures and heart rate or with a chronic, indwelling venous catheter to obtain sequential blood samples for the determination of plasma levels of stress related hormones (catecholamines, corticosterone and prolactin). Additional variables (weight gain, food and water consumption and estrous cyclicity) will also be monitored to gauge the physiologic status of the rats. The housing conditions to be evaluated are: isolated (single) housing, paired (double) housing, isolated housing with "chew" and "climbing/hiding" "toys" and isolated housing with access to a very enriched environment for a short period each day. Adaptation to the environmental housing conditions will also be evaluated. Common husbandry and experimental manipulations to which animals are to be exposed or witness being done on other animals will include: removal to a new cage, hand restraint and a s.c. injection, placement in a rodent restrainer for a short period with a tail vein injection, witnessing the decapitation of other animals and witnessing a tissue harvest from other animals. Although this project is a descriptive one and not hypothesis driven, it should provide very practical and important results that can be used by local IACUCs as they review animal protocols and by national organizations such as the PHS, AAALAC, ILAR and USDA as they promulgate requirements, guidelines and regulations in this area.