Summary

一种新的方法为评估味质的实验室大鼠的补强性能:操作性口腔自我管理

Published: February 06, 2014
doi:

Summary

目前的研究评估了一种新的程序,以评估可口的解决方案在实验室老鼠的增强作用:口内的自我管理。为此,操作性响应( 杠杆按压),用于甜的解决方案在不同浓度的口腔内输注上测量钢筋连续和渐进比时间表。

Abstract

本文介绍了一种新方法研究瘾食物的生物行为的基础。这种方法结合了味道的反应与药物操作性自我管理的行为方面的手术成分。在非常短暂的全身麻醉,将大鼠植入口腔内(IO),插管直接允许在口腔内递送的测试解决方案。然后将动物的操作性自我管理室测试,使他们能够按杠杆接收测试解决方案的IO输注。 IO自我管理方面拥有逾涉及饮用从一个喷口或操作性回应固体颗粒或在容器交付解决方案解决实验过程的几个优点。这里,我们表明,IO自行给药可用于研究的高果糖玉米糖浆(HFCS)自我给药。大鼠首先测试的自我管理上的一个进步率(PR)的日程安排,评估运算的最高金额erant行为,将不同浓度高果糖浆( 8%,25%和50%)的发射。下面这个测试,大鼠自我管理这些浓度对加固连续时间表( 即,一个输液每个杆出版社),连续10天(1次/天;每次持续3小时),然后他们再次接受测试的公关时间表。在连续加固时间表,大鼠把高浓度的减少输注,虽然高果糖浆的最低浓度(8%)保持更可变的自我管理。此外,在PR测试显示,8%有下部加强值超过25%和50%。这些结果表明,IO自我给药可以用来研究获得和维持响应于甜的解决方案。在浓度和加固进度差异的操作反应的灵敏度使得IO自我管理的理想方法研究自由采食量的神经生物学Õf甜食。

Introduction

上瘾食物的神经生物学和行为基础的研究依赖于,类似于滥用药物,过量食用可口食物,促进行为的依赖1-4的意见和诱导改变大脑奖赏回路在人和5-6和实验室动物7-8。但是,尽管有几个协议和用于研究的药物滥用在实验室老鼠的成瘾性,以适应这些方法来评估由食物诱发提出了独特的挑战“上瘾”的行为过程。本研究的目的是要操作性静脉注射(IV)药物的自我管理的原则,适用于口内(IO)输液甜交付解决方案的操作性自我管理的调查。甜蜜采用了高果糖玉米糖浆(HFCS),因为尽管有争议,有证据表明,高果糖浆可能与肥胖9-12的现代流行病。

传统上,IO输注交付研究促味剂的适口性味觉反应的实验13。简单地说,一个IO插管手术植入到大鼠和各种解决方案的IO输注的脸颊是被动地交付了14。的目标是研究动物的口面部反应的促味剂。然而,IO插管也已经长期植入大鼠腭,以确定它们是否会学习按杠杆自行INFUSE解决方案直接到他们的口腔内,因此这个词的IO自行注射15-17。在目前的研究中,我们描述了利用小手术并允许长期操作性自我给药试验的过程。这个程序拥有涉及从壶嘴(一),或操作性回应固体颗粒喝了解决方案,传统的程序几个显著的优势(二),或操作性回应流体在一个容器交付滴(三)。

相比于(a)中,IO自行给药涉及一个操作反应( 按压杠杆),因此它可以修改调度调节响应的要求和提供的IO输注之间的关系。例如,通过采用累进比(PR)的时间表,由此需要连续输注反应的会话18内成倍增加,能够以评估多少动物“要”的下一个输注19。当动物喝从壶嘴的解决方案,除非它控制流体输送及监控响应一个特殊的装置,采用20这个重要的“求”的行为方面无法评估。此外,IO自我管理提供了一个平均值进行比较的行为由不同的强化刺激的动机。也就是说,它可以比较操作性由糖果和其它增强剂,如滥用药物在应对维护所谓的“替代研究。”

相比于(b)所示,IO自行给药允许任何浓度的测试和任何水溶性食品添加剂的任何体积。因为,在我们所知,有果糖没有市售的固体颗粒或以不同比例的果糖,葡萄糖组合,这是非常重要的学习行为由甜食,如高果糖浆的动机,那将是适合于操作室。此外,控制和操纵浓度/体积比的重要性是强制性的实验中摄取既可以通过溶液(导致营养物特异性的饱腹感)的热值和由该如何解决的多少可以在给定的消耗来调制一段时间后( 丰满)21。 IO自我管理也缩短了操作反应和传递的主要增强剂,即起着收购和维护具有重要作用的一个因素之间的延迟南切操作行为16,22-23。

最后,在比较(c)中,IO自我管理允许受控的试验溶液的量的被动IO输注递送,并且这使得可以测量“喜欢”的口面的反应(目标享乐反应如舌突起24 -25)和IO是否自我管理过程中这些反应改变。此外,管理被动的IO输注的能力有复发的食物寻求学习显著应用。也就是说,在静脉注射毒品的自我管理的研究,以下灭绝的时期,素药物(小剂量药物26 管理)可以“恢复”响应27-28。因此,提供的IO输注而对动物的任何行动的能力,可用于研究“食”引复职,以及潜在的交叉复职食物之间滥用药物。

甜美的解决方案IO自我管理也是可取的IV和胃内自我管理。事实上,虽然果糖在人类和实验动物静脉注射产生的生理后果类似的观察口服消费29-31,这是甜食是如何正常消耗( 口服)一个贫穷的模型。此外,通过咀嚼产生的味觉信号赋予有关食物的适口性的重要信息,而当省略这个阶段的消化过程,适应不良行为,如暴饮暴食的发展降低了32-33。

Protocol

1。动物护理及房屋所有的实验都是由圭尔夫大学动物护理委员会批准,并按照加拿大理事会关于动物保护的建议进行的。目前的研究中包括22个成年雄性Sprague-Dawley大鼠(Charles River,QC)称重200-225克在实验的开始。 单家老鼠和维护它们在反向光/暗周期(上午7时关闭 – 下午7:00开)与自由采食获得食物和水除另有指明外,或在此期间,在活动周期发生行为测试。 <li…

Representative Results

收购IO自我管理 图3表示操作性期间的8%,25%,或50%高果糖浆,连续10届自我管理的有效和无效的杠杆回应。大鼠获得高果糖浆的IO自我管理的前三个阶段内,并保持稳定的主动杆响应(如上所述),以收购的其余部分。在主动杆响应的浓度依赖性的差异也很明显:相比于25%时,响应是显著降低大鼠个体施用50%高果糖浆。测试的最低浓度(8%)保持操?…

Discussion

目前的研究显示了一种新的方法相结合,采用传统的学习行为由滥用药物(静脉操作性自我管理)的积极性,并评估促味剂的适口性(通过口内注射味道的反应)方法评估甜美解决方案的增强特性。为此,非常简短的异氟烷诱导麻醉下,将大鼠植入一个IO套管,其允许输送试验溶液直接进入他们的嘴。以下从手术恢复,将动物在操作性自我给药试验室,由此他们可以按杠杆得到试验溶液的IO输注。…

Divulgations

The authors have nothing to disclose.

Acknowledgements

这些研究是由赠款从加拿大自然科学和工程研究理事会(NSERC)为FL和加拿大研究生奖学金(CGSD)由NSERC到AM.L.支持

Materials

Reagents
Meloxicam Boehringer Ingelheim Canada Ltd. From the Ontario Veterinary College pharmacy
Procaine Penicillin G Pen Aqueous, Wyeth Animal Health From the Ontario Veterinary College pharmacy
Lidocaine HCl 2% From the Ontario Veterinary College pharmacy
Marcaine 0.5 % From the Ontario Veterinary College pharmacy
Lubricating eye ointment Product can be bought at any pharmacy
2% Lidocaine Viscous Oral (Topical Anesthetic) Pharmascience Inc. CDMV # 14705 100 ml bottle
Isoflurane USP Pharmaceutical Partners of Canada CDMV # 108737 250 ml bottle
Bacti-Stat Merck Sante Animale CDMV # 6449 3.785 L bottle
Isopropyl alcohol (70%) Perdu Pharma Fisher # MPX18404 4 L bottle
Betadine 10% McKesson Canada CDMV # 104826 500 ml bottle
Super Germiphene Ceva Animal Health CDMV # 103629 454 ml bottle
Chlorhexidene(Novadent) Zoetis CDMV # 8908 236 ml bottle
High Fructose Corn Syrup Natures Flavours HFCS-55 1 Gallon bottle
Materials
PE90 tubing Becton Dickinson and Company VWR # CA-63019-080A 100 ft/coil
PE160 tubing Becton Dickinson and Company VWR # CA-63018-747 100 ft/coil
Polypropylene Mesh Small Parts Inc. CMP-0297-D
Soldering iron Product can be bought at any hardware store
# 64 Elastic bands Staples Office supplies Item # 13556 Product can be bought at any office supply store
15 G thin-walled 3.5 inch needles VWR # CABD1108 12 needles per pack
Electric razor (1/2 in wide blade) Product can be bought at any pet supply store
Percision Glide Needles 20 G needles (1 ½ in) Becton Dickinson and Company Fisher # 14-826D
Percision Glide Needles 16 G needles (1 ½ in) Becton Dickinson and Company Fisher # 14-826-5D
Operant conditioning chambers Med Associates Inc. ENV-008-CTC
Sound attenuating chamber Med Associates Inc. ENV-018M
MED PC IV software Med Associates Inc. SOF-735
Syringe Pumps Razel Scientific Instruments
Disposable plastic swivel assembly Med Associates Inc. PHM-115I
Tygone Microbore tubing Saint Gobain Performance Plastics Fisher # 1417015B 500 ft/coil

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Levy, A., Limebeer, C. L., Ferdinand, J., Shillingford, U., Parker, L. A., Leri, F. A Novel Procedure for Evaluating the Reinforcing Properties of Tastants in Laboratory Rats: Operant Intraoral Self-administration. J. Vis. Exp. (84), e50956, doi:10.3791/50956 (2014).

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