This work was supported by a CIHR operating grant (MOP-102624) to Q. Y. We thank Dr Carolyn Harley for helpful discussions throughout the study, Dr. Qinlong Hou, Amin Shakhawat, and Andrea Darby-King for technical support.

无论男女，只SD大鼠（查尔斯河）的幼崽被使用。窝被扑杀，以12 PD1（出生是PD0）。水坝维持12小时的光/暗周期， 随意获取食物和水。实验步骤已通过纪念大学实验动物管理委员会。 1，鼻封堵施工注:此程序改编和卡明斯等人修改（1997）35。 <ol><li> AQUIRE聚乙烯20管和3-0丝线缝合线。 </li><li>剪一小块聚乙烯管材20到约0.8mm。 </li><li>螺纹丝缝线穿过准备管，使得有螺纹的管的部分的任一侧。 </li><li>在插头外螺纹的一端，打结的线。 </li><li>管拉下来了，在螺纹结的部分。结应提出管内。</li><li>修剪的螺纹，使得〜2毫米螺纹的从管的一端突出的两端（ 见图1A）。 </li></ol>训练前2娜丽丝闭塞<ol><li>在一个安全的菜铺上被褥定期删除大坝和地点的小狗。 </li><li>用棉签应用轻拍局部麻醉果冻，2％利多卡因，在鼻孔被遮挡。 </li><li>让小狗休息的菜〜3分钟。 </li><li>轻轻但稳固地握住小狗在非优势手。 </li><li>使用优势手，拿起一个鼻子插头并轻轻从该线程不突出的尖端周围的相同的局部麻醉果冻。这将作为这两种麻醉与插头插入相关的任何轻​​微疼痛，并会担任鼻孔内的润滑剂。注:利多卡因的效果开始不到两分钟，持续20-30分钟。幼仔一般表现出良好的耐受性的插头插入后利多卡因凝胶的应用（M挣扎的最小值和发声）。 </li><li>轻轻地紧紧抱着小狗，慢慢地旋转插头很温柔推，直到插头完全插入，只有2毫米螺纹从鼻孔插入伸出鼻子塞（ 见图1B）。应该有从任一鼻孔在此过程中没有出血。鼻子插头插入时有出血幼崽被排除在外，回到水坝</li><li>让动物休息的这盘5分钟才能到，观察者插头。 </li><li>取下习惯菜的小狗，并开始调节模式24。 </li></ol><img alt="图1" fo:content-width="5in" src="/files/ftp_upload/51808/51808fig1highres.jpg" width="500" /> 图1。施工鼻子塞。 A）的示意图显示使鼻子塞的步骤。线程是通过聚乙烯管拉;一个结是由和PUL领进油管，以阻止它的中间;两端切有2mm残留在一端从管接头。 的B）前，用在一个鼻孔鼻插头大鼠的侧视图。 3，香味床上准备<ol><li>戴新手套，在通风橱，以防止异味污染，将500毫升木屑铺垫成一个塑料袋。 </li><li>用注射器吸取了0.3毫升薄荷提取物，并喷上这种在塑料袋中的床上用品。 </li><li>扎紧袋口封住，摇晃剧烈袋，并允许被褥休息收入囊中5分钟。 </li><li>将香味寝具清晰，浅，丙烯酸培训发现在通风橱中使用的前5分钟盒（20×20×5厘米3， 图2A）。一旦被褥准备，放弃这些手套，不要让这些手套来与动物接触。 </li><li>将无迹寝具相同的透明塑料盒，以及连接确保不接触到香味的被褥或使用的手套接触。 </li></ol> 4，气味调节范式（参见图图2A） 幼崽接受任何一个单一的空调会议上，PD 6或多个审判庭（每天一次会议，PD 3-6）。 <ol><li>广场上香气四溢的床上用品习惯于小狗。对于控制气味只有（O / S - ）的幼崽，离开被褥10分钟这些幼崽，然后跳到步骤4.5。对于实验异味+行程（O / S +）的幼崽，继续在本节下面的步骤。 </li><li>行程小狗30秒使用小画笔。使用快速打圈主要围绕着小狗的后腿区域。 </li><li>让小狗休息30秒。 </li><li>重复步骤4.2和4.3共10分钟（ 即 10配对行程+异味）。 </li><li>从调理盒中取出的小狗，取出鼻子塞和小狗回到大坝。 </li></ol> &lt;P舱="jove_title"&gt; 5。单侧气味偏好测试（参见图图2B） 测试发生在不同时间点（ 例如 ，24或48小时）之后的最后的训练会话。试验是在一个不锈钢测试腔室（30×20×18 毫升 ），它被放置在两个训练拖曳（训练框在3.4中描述），以2厘米的中性区域分开顶部。一个培训箱含有薄荷香味的床上用品，而另一盒包含清洁，无味的床上用品。测试腔室的底板是金属网格，然后将其覆盖的塑料网状物的可移动片（ 图2B）。 <ol><li>制备1薄荷油和一种无味寝具按照第3章，并将其放置在测试室中，相距2厘米的相对侧上的每个方块。放在试验室的金属网格地板的塑料网。 </li><li>从大坝拆除的小狗和地点无味硅脂坚定民建联的鼻孔在训练中被遮挡。重新申请需要整个第一测试过程中润滑脂。注意:在训练和测试随机鼻孔闭塞，可以考虑，以避免偏差。 </li><li>放置小狗在测试室的中性区。 </li><li>让小狗探索室1分钟，记录多久的小狗花了室的两侧（ 即超过薄荷或中性香味的床上用品）。 </li><li>让小狗在一个带盖的塑料保持室休息1分钟。 </li><li>共10分钟，重复步骤5.2和5.3（ 即由5其余试验分离5试验试验）交换腔室中的幼犬的初始方向，以控制对方向的偏好。 </li><li>紧随其后的测试，擦去从鼻孔油脂。 </li><li>将聚乙烯noseplug到相反鼻孔按照第2节，让动物休息10分钟。 </li><li>再次测试的小狗在<html> 5.3 -5.6，拔下电源插头，并小狗回到大坝。除去和清洗试验室用95％乙醇的塑料网，并允许液体蒸发。测试下一小狗之前，将网格回来。 注意:在测试过程中的应用硅脂在第一鼻孔闭塞防止出血和鼻插头插入有关的应力的机会。 </li></ol><img alt="图2" fo:content-width="5in" src="/files/ftp_upload/51808/51808fig2highres.jpg" width="500" /> 图2:早期气味偏好的培训和测试。一）早期气味偏好使用气味+抚摸着范式乙训练。）的一个侧面薄荷寝具两个选择气味偏好测试，控制无味的床上用品在另一侧。 2厘米中立区被放置在中间。 6，测试单娜丽丝闭塞的有效性NT"&gt;本实验的目的是确定单个鼻孔闭塞是否导致嗅觉系统的单侧激活。 <ol><li>在第2节中描述到PD 6或7的幼崽进行单侧鼻孔闭塞。 </li><li>后〜5分钟习惯，将幼鼠在有盖的塑料容器中，并暴露于30微升纯薄荷油浸泡在一块组织10分钟。 </li><li>紧接着的薄荷气味曝光，腹腔（IP）与水合氯醛（400毫克/千克）为全身麻醉，或戊巴比妥（150毫克/千克）注入小狗。 </li><li>一旦完全麻醉（示于尾部或脚捏无响应），transcardially灌注小狗用生理盐水（0.9％）为〜1分钟的冰冷溶液，随后的多聚甲醛（4％，溶于0.1M磷酸盐缓冲溶液，PBS ）。 </li><li>后的多聚甲醛灌注的10分钟，收集大脑，并放置在多聚甲醛中过夜，在4℃，然后反FER大脑到蔗糖溶液（在PBS中的20％），另外24小时。 </li><li>冠状切开大脑切片在30微米厚度与低温恒温器。收集转播和PC片和安装到明胶包被的载玻片，其次是标准的免疫组化染色区pCREB抗体21,25,30。 </li></ol> 7，测试单娜丽丝闭塞的可逆性该实验测试的阻挡效果是否是可逆的，在24小时之后除去鼻子塞。 <ol><li>在第2节中描述到PD 6或7的幼崽进行单侧鼻孔闭塞。 </li><li> 15分钟后（相当于鼻孔闭塞的持续时间期间训练 - 5分钟驯化+ 10分钟训练），除去鼻插头和小狗返回到坝。 </li><li> 24小时后，在6.2中描述揭露小狗的薄荷气味在有盖的塑料容器10分钟。 </li><li>按照教派相同的步骤离子6.3-6.6。 </li></ol>

<ol>
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W., Yuan, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Olfactory+bulb+alpha2-adrenoceptor+activation+promotes+rat+pup+odor-preference+learning+via+a+cAMP-independent+mechanism.">Olfactory bulb alpha2-adrenoceptor activation promotes rat pup odor-preference learning via a cAMP-independent mechanism.</a> Learn Mem. 19, 499-502 (2012).</li><li>Isaacson, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Odor+representations+in+mammalian+cortical+circuits.">Odor representations in mammalian cortical circuits.</a> Curr Opin Neurobiol. 20, 328-331 (2010).</li><li>Lethbridge, R., Hou, Q., Harley, C. W., Yuan, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Olfactory+bulb+glomerular+NMDA+receptors+mediate+olfactory+nerve+potentiation+and+odor+preference+learning+in+the+neonate+rat.">Olfactory bulb glomerular NMDA receptors mediate olfactory nerve potentiation and odor preference learning in the neonate rat.</a> PLoS One. 7, e35024 (2012).</li><li>Yuan, Q., Harley, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=What+a+nostril+knows:+olfactory+nerve-evoked+AMPA+responses+increase+while+NMDA+responses+decrease+at+24-h+post-training+for+lateralized+odor+preference+memory+in+neonate+rat.">What a nostril knows: olfactory nerve-evoked AMPA responses increase while NMDA responses decrease at 24-h post-training for lateralized odor preference memory in neonate rat.</a> Learn Mem. 19, 50-53 (2012).</li><li>Schwob, J. E., Price, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+development+of+axonal+connections+in+the+central+olfactory+system+of+rats.">The development of axonal connections in the central olfactory system of rats.</a> J Comp Neurol. 223, 177-202 (1984).</li><li>Kucharski, D., Hall, W. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+routes+to+early+memories.">New routes to early memories.</a> Science. 238, 786-788 (1987).</li><li>Kucharski, D., Johanson, I. B., Hall, W. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unilateral+olfactory+conditioning+in+6-day-old+rat+pups.">Unilateral olfactory conditioning in 6-day-old rat pups.</a> Behav Neural Biol. 46, 472-490 (1986).</li><li>Cummings, D. M., Henning, H. E., Brunjes, P. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Olfactory+bulb+recovery+after+early+sensory+deprivation.">Olfactory bulb recovery after early sensory deprivation.</a> J Neurosci. 17, 7433-7440 (1997).</li><li>Kucharski, D., Hall, W. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developmental+change+in+the+access+to+olfactory+memories.">Developmental change in the access to olfactory memories.</a> Behav Neurosci. 102, 340-348 (1988).</li><li>Brunjes, P. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unilateral+odor+deprivation:+time+course+of+changes+in+laminar+volume.">Unilateral odor deprivation: time course of changes in laminar volume.</a> Brain Res Bull. 14, 233-237 (1985).</li><li>Kass, M. D., Pottackal, J., Turkel, D. J., McGann, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Changes+in+the+neural+representation+of+odorants+after+olfactory+deprivation+in+the+adult+mouse+olfactory+bulb.">Changes in the neural representation of odorants after olfactory deprivation in the adult mouse olfactory bulb.</a> Chem Senses. 38, 77-89 (2013).</li><li>Kim, H. H., Puche, A. C., Margolis, F. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Odorant+deprivation+reversibly+modulates+transsynaptic+changes+in+the+NR2B-mediated+CREB+pathway+in+mouse+piriform+cortex.">Odorant deprivation reversibly modulates transsynaptic changes in the NR2B-mediated CREB pathway in mouse piriform cortex.</a> J Neurosci. 26, 9548-9559 (2006).</li><li>Korol, D. L., Brunjes, P. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+changes+in+2-deoxyglucose+uptake+and+amino+acid+incorporation+following+unilateral+odor+deprivation:+a+laminar+analysis.">Rapid changes in 2-deoxyglucose uptake and amino acid incorporation following unilateral odor deprivation: a laminar analysis.</a> Brain Res Dev Brain Res. 52, 75-84 (1990).</li><li>Leung, C. H., Wilson, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trans-neuronal+regulation+of+cortical+apoptosis+in+the+adult+rat+olfactory+system.">Trans-neuronal regulation of cortical apoptosis in the adult rat olfactory system.</a> Brain Res. 984, 182-188 (2003).</li></ol>

The authors have nothing to disclose.

首先由霍尔及其同事建立了幼鼠的单侧臭味学习和记忆模型中的一个关键的时间窗口。在一系列的研究中33,34,36，他们发现气味偏好的内存可以通过气味+豆浆配对的幼鼠进行单侧一个鼻孔在帕金森病6。偏好的记忆是强大的，当同样的鼻孔是在训练和测试开放的，但没有观察到，当闭塞鼻孔是畅通和测试。然而，在帕金森病12，当来自前嗅皮层前连合的连接成为功能32，未受过训练?...

嗅觉是初级感觉方式在啮齿类动物中，没有它们就不能成功地浏览或在其环境中生存。这是新生儿的幼崽，它可以既看不见也听不到在第一产后一周，用嗅觉，以找到他们的母亲喂养1尤其重要。因此，新生儿幼鼠能条件反射地偏爱气味与简单的实验操作。各种刺激已被用来作为非条件刺激（UCS）以诱导调节的反应，新颖的气味（条件刺激，CS）的新生儿，包括嵌套环境2,3，乳乳4-6，抚摸或触觉刺激7- 12，尾巴捏13，产妇的唾液13，轻度电击足底14-18，和颅内脑刺激19。本研究采用了一种行之有效的早期气味偏好的模式，其中的气味，在这种情况下薄荷，我š以产生偏爱薄荷24小时后10,11,20结合触觉刺激。这些气味的记忆是依赖于完整的嗅觉电路，主要包括嗅球（OB）21-23和前梨状皮质（APC）24,25。 早期的气味偏好的学习实验研究，加深和拓宽了我们的哺乳动物记忆的分子和生理基础的理解。这种哺乳动物模型具有学习记忆机制的几大优势。首先，UCS信号的神经来源已经确定。如上面提到的各种刺激刺激蓝斑的去甲肾上腺素释放26，从而激活多个肾上腺素能受体中的转播和APC，引起支持学习22,27,28细胞和生理效应。第二，存储器 - 支持机制发生在良好定义的层的神经结构。该新生大鼠嗅觉电路简洁为研究人员提供与发掘相关的突触可塑性的复杂过程的理想框架。嗅觉的感觉神经元（OSN）中的嗅觉上皮项目上二尖瓣/簇绒细胞中的转播和这些二尖瓣/簇绒细胞反过来项目同侧经由横向嗅束（LOT）梨状皮层（PC），其他结构29之间。无论是在OB 30,31的OSN突触和突触地段24,25参阅APC已被确定为关键位点为支持学习记忆的突触变化和。第三，在幼年大鼠，嗅觉输入可以很容易地单侧。每个APC有一次，通过这种白色物质完全形成，在产后第12天（PD12）32前联合访问两国的气味信息。帕金森病12日前，异味输入可隔离通过单鼻孔闭塞24,25,31,33,34 &lt;到ipisilateral转播和APC/ SUP&gt;。单鼻孔闭塞允许从开启鼻孔的气味记忆的形成，并且防止在同一存储器从现有的闭塞鼻孔到PD 12 33。气味存储器分离到同侧半球包括OB和APC。因此，每只大鼠的小狗可以自己控制学习和支撑生理学。 在本研究中，单侧早期气味偏好学习协议被引入。该方法可作为一种强大的工具用于研究通过提供一种帧内动物控制24,25,31，从而减少了所需的动物数量和一般的变异支撑气味学习神经机制。鼻孔闭塞是可逆的，所述润滑脂或鼻子塞可以应用和以最小的应力或者损坏的动物中移除。在这里，首先，早期气味偏好的培训和测试的详细过程进行了描述，重点是使用单鼻孔闭塞了号的单侧协议ê插头。然后结果被提出来证明在分离的气味输入并产生单侧气味存储器单鼻孔闭塞的有效性。最后，利用该单侧学习模型来研究生理变化的嗅觉系统，这两个生成学习和支撑记忆表达的潜力进行了讨论。

<table border="0" cellpadding="0" cellspacing="0" width="580">
	<tbody>
		<tr height="50">
			<td height="50" style="height:50px;width:149px;">Polythylene 20 tubing</td>
			<td style="width:123px;">Intramedic</td>
			<td style="width:103px;">427406</td>
			<td style="width:205px;">Non radiopaque, Non toxic</td>
		</tr>
		<tr height="50">
			<td height="50" style="height:50px;width:149px;">3-0 silk suture thread</td>
			<td style="width:123px;">Syneture</td>
			<td style="width:103px;">Sofsilk</td>
			<td style="width:205px;">Non absorbant&#160;</td>
		</tr>
		<tr height="50">
			<td height="50" style="height:50px;width:149px;">Silicone grease</td>
			<td style="width:123px;">Warner Instrument</td>
			<td style="width:103px;">64-0378</td>
			<td style="width:205px;">Odorless</td>
		</tr>
		<tr height="50">
			<td height="50" style="height:50px;width:149px;">2% xylocaine gel</td>
			<td style="width:123px;">AstraZeneca</td>
			<td style="width:103px;">Prod. No 061</td>
			<td style="width:205px;">Lidocaine hydrochloride jelly,&#160; purchased at local pharmacy</td>
		</tr>
		<tr height="50">
			<td height="50" style="height:50px;width:149px;">Paint brush</td>
			<td style="width:123px;">Dynasty</td>
			<td style="width:103px;">206R</td>
			<td style="width:205px;">Similar size/other brands work too</td>
		</tr>
		<tr height="50">
			<td height="50" style="height:50px;width:149px;">Peppermint extract</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:103px;">W284807</td>
			<td style="width:205px;">Other brand should be okay too</td>
		</tr>
		<tr height="171">
			<td height="171" style="height:171px;width:149px;">Training box</td>
			<td style="width:123px;">Custom-made</td>
			<td style="width:103px;">N/A</td>
			<td style="width:205px;">Acrylic box (20x20x5cm3), see Figure 2A. Parameters and material for the box are not critical and can be modified. Material used should be odorless and does not absorb odors</td>
		</tr>
		<tr height="182">
			<td height="182" style="height:182px;width:149px;">Testing chamber</td>
			<td style="width:123px;">Custom-made</td>
			<td style="width:103px;">N/A</td>
			<td style="width:205px;">Stainless steel (30x20x18cm3), see Figure 2B. Parameters and material for the chamber are not critical and can be modified. For example, an acrylic chamber instead of a stainless steel one can be used</td>
		</tr>
		<tr height="50">
			<td height="50" style="height:50px;width:149px;">pCREB antibody</td>
			<td style="width:123px;">Cell Signaling</td>
			<td style="width:103px;">9198</td>
			<td style="width:205px;">Ser 133 (87G3) Rabbit mAb</td>
		</tr>
		<tr height="50">
			<td height="50" style="height:50px;width:149px;">Chloral hydrate</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:103px;">C8383</td>
			<td style="width:205px;">N/A</td>
		</tr>
		<tr height="50">
			<td height="50" style="height:50px;width:149px;">Paraformaldehype</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:103px;">P6148</td>
			<td style="width:205px;">N/A</td>
		</tr>
		<tr height="50">
			<td height="50" style="height:50px;width:149px;">Sucrose</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:103px;">S9378</td>
			<td style="width:205px;">N/A</td>
		</tr>
	</tbody>
</table>

a lateralized odor learning model in neonatal rats for dissecting neural circuitry underpinning memory formation

Rat pups during a critical postnatal period (&#8804; 10 days) readily form a preference for an odor that is associated with stimuli mimicking maternal care. Such a preference memory can last from hours, to days, even life-long, depending on training parameters. Early odor preference learning provides us with a model in which the critical changes for a natural form of learning occur in the olfactory circuitry. An additional feature that makes it a powerful tool for the analysis of memory processes is that early odor preference learning can be lateralized via single naris occlusion within the critical period. This is due to the lack of mature anterior commissural connections of the olfactory hemispheres at this early age. This work outlines behavioral protocols for lateralized odor learning using nose plugs. Acute, reversible naris occlusion minimizes tissue and neuronal damages associated with long-term occlusion and more aggressive methods such as cauterization. The lateralized odor learning model permits within-animal comparison, therefore greatly reducing variance compared to between-animal designs. This method has been used successfully to probe the circuit changes in the olfactory system produced by training. Future directions include exploring molecular underpinnings of odor memory using this lateralized learning model; and correlating physiological change with memory strength and durations.

在这里，我们回顾一些先前建立的结果24，以显示在分离的气味输入和学 ​​习到一个半球的鼻孔闭塞的有效性，并且该方法的可逆性。 在早期的气味偏好训练单鼻孔闭塞导致单侧气味记忆24。该存储器被限制在幸免鼻孔（ 图3）。当幼崽进行了测试气味的喜好与同鼻孔闭塞的训练时，他们表现出偏爱空调异味（ 如薄荷）。当幼崽与封闭相...

Watch this Scientific Journal Video about A Lateralized Odor Learning Model in Neonatal Rats for Dissecting Neural Circuitry Underpinning Memory Formation at JoVE.com

A Lateralized Odor Learning Model in Neonatal Rats for Dissecting Neural Circuitry Underpinning Memory Formation

This protocol introduces lateralized early odor preference learning in rats using acute single naris occlusion. Lateralized learning permits the examination of behavioral outcomes and underpinning biological mechanisms within the same animals, reducing variance induced by between-animal designs. This protocol can be used to investigate molecular mechanisms underpinning early odor learning.

新生大鼠于A气味偏侧学习模型解剖神经回路托换记忆的形成

Rat pups during a critical postnatal period (&#8804; 10 days) readily form a preference for an odor that is associated with stimuli mimicking maternal ...

a-lateralized-odor-learning-model-neonatal-rats-for-dissecting-neural

Universidad de Cartagena UDEC

Research

JoVE Journal

Neuroscience

8.9K 次观看.  Faculty of Medicine, Memorial University. This protocol introduces lateralized early odor preference learning in rats using acute single naris occlusion. Lateralized learning permits the examination of behavioral outcomes and underpinning biological mechanisms within the same animals, reducing variance induced by between-animal designs. This protocol can be used to investigate molecular mechanisms underpinning early odor learning.

视频: A Lateralized Odor Learning Model in Neonatal Rats for Dissecting Neural Circuitry Underpinning Memory Formation

C. elegans Positive Butanone Learning, Short-term, and Long-term Associative Memory Assays

The memory of experiences and learned information is critical for organisms to make choices that aid their survival. C. elegans navigates its environment through neuron-specific detection of food and chemical odors1, 2, and can associate nutritive states with chemical odors3, temperature4, and the pathogenicity of a food source5.
Here, we describe assays of C. elegans associative learning and short- and long-term associative memory. We modified an aversive olfactory learning paradigm6 to instead produce a positive response; the assay involves starving ~400 worms, then feeding the worms in the presence of the AWC neuron-sensed volatile chemoattractant butanone at a concentration that elicits a low chemotactic index (similar to Toroyama et al.7). A standard population chemotaxis assay1 tests the worms' attraction to the odorant immediately or minutes to hours after conditioning.
After conditioning, wild-type animals' chemotaxis to butanone increases ~0.6 Chemotaxis Index units, its "Learning Index". Associative learning is dependent on the presence of both food and butanone during training. Pairing food and butanone for a single conditioning period ("massed training") produces short-term associative memory that lasts ~2 hours. Multiple conditioning periods with rest periods between ("spaced training") yields long-term associative memory (&lt;40 hours), and is dependent on the cAMP Response Element Binding protein (CREB),6 a transcription factor required for long-term memory across species.8
Our protocol also includes image analysis methods for quick and accurate determination of chemotaxis indices. High-contrast images of animals on chemotaxis assay plates are captured and analyzed by worm counting software in MatLab. The software corrects for uneven background using a morphological tophat transformation.9 Otsu's method is then used to determine a threshold to separate worms from the background.10 Very small particles are removed automatically and larger non-worm regions (plate edges or agar punches) are removed by manual selection. The software then estimates the size of single worm by ignoring regions that are above a specified maximum size and taking the median size of the remaining regions. The number of worms is then estimated by dividing the total area identified as occupied by worms by the estimated size of a single worm.
We have found that learning and short- and long-term memory can be distinguished, and that these processes share similar key molecules with higher organisms.6,8 Our assays can quickly test novel candidate genes or molecules that affect learning and short- or long-term memory in C. elegans that are relevant across species.

C. elegans Positive Butanone Learning, Short-term, and Long-term Associative Memory Assays

Here we describe methods to test C. elegans associative learning and short- and long-term associative memory. These population assays employ the worms abilities to chemotax toward volatile odorants, and form positive associations upon pairing food with the chemoattractant butanone. Increasing the number of conditioning periods induces long-term memory.

线虫的积极丁酮学习，短期，长期联想记忆检测

The memory of experiences and learned information is critical for organisms to make choices that aid their survival. C. elegans navigates its environment ...

科研

神经科学

Assaying Locomotor, Learning, and Memory Deficits in Drosophila Models of Neurodegeneration

Advances in genetic methods have enabled the study of genes involved in human neurodegenerative diseases using Drosophila as a model system1. Most of these diseases, including Alzheimer's, Parkinson's and Huntington's disease are characterized by age-dependent deterioration in learning and memory functions and movement coordination2. Here we use behavioral assays, including the negative geotaxis assay3 and the aversive phototaxic suppression assay (APS assay)4,5, to show that some of the behavior characteristics associated with human neurodegeneration can be recapitulated in flies. In the negative geotaxis assay, the natural tendency of flies to move against gravity when agitated is utilized to study genes or conditions that may hinder locomotor capacities. In the APS assay, the learning and memory functions are tested in positively-phototactic flies trained to associate light with aversive bitter taste and hence avoid this otherwise natural tendency to move toward light. Testing these trained flies 6 hours post-training is used to assess memory functions. Using these assays, the contribution of any genetic or environmental factors toward developing neurodegeneration can be easily studied in flies.

Assaying Locomotor, Learning, and Memory Deficits in Drosophila Models of Neurodegeneration

Behavior assays for measuring locomotor functions, learning, and memory abilities in Drosophila.

含量的运动能力，学习和记忆的赤字果蝇</em神经退行性疾病>模型

Advances in genetic methods have enabled the study of genes involved in human neurodegenerative diseases using Drosophila as a model system1. Most of ...

Morris Water Maze Test for Learning and Memory Deficits in Alzheimer&#39;s Disease Model Mice

The Morris Water Maze (MWM) was first established by neuroscientist Richard G. Morris in 1981 in order to test hippocampal-dependent learning, including acquisition of spatial memoryand long-term spatial memory 1. The MWM is a relatively simple procedure typically consisting of six day trials, the main advantage being the differentiation between the spatial (hidden-platform) and non-spatial (visible platform) conditions 2-4. In addition, the MWM testing environment reduces odor trail interference 5. This has led the task to be used extensively in the study of the neurobiology and neuropharmacology of spatial learning and memory. The MWM plays an important role in the validation of rodent models for neurocognitive disorders such as Alzheimer&#x2019;s Disease 6, 7. In this protocol we discussed the typical procedure of MWM for testing learning and memory and data analysis commonly used in Alzheimer&#x2019;s disease transgenic model mice.

Morris Water Maze Test for Learning and Memory Deficits in Alzheimer's Disease Model Mice

The Morris Water Maze is a behavioral task to test hippocampal-dependent learning and memory. It has been widely used in the study of neurobiology, neuropharmacology and neurocognitive disorders in rodent models.

在阿尔茨海默氏病模型小鼠学习和记忆障碍的Morris水迷宫测试

The Morris Water Maze (MWM) was first established by neuroscientist Richard G. Morris in 1981 in order to test hippocampal-dependent learning, including ...

Reproducible Mouse Sciatic Nerve Crush and Subsequent Assessment of Regeneration by Whole Mount Muscle Analysis

Regeneration in the peripheral nervous system (PNS) is widely studied both for its relevance to human disease and to understand the robust regenerative response mounted by PNS neurons thereby possibly illuminating the failures of CNS regeneration1. Sciatic nerve crush (axonotmesis) is one of the most common models of peripheral nerve injury in rodents2. Crushing interrupts all axons but Schwann cell basal laminae are preserved so that regeneration is optimal3,4. This allows the investigator to study precisely the ability of a growing axon to interact with both the Schwann cell and basal laminae4. Rats have generally been the preferred animal models for experimental nerve crush. They are widely available and their lesioned sciatic nerve provides a reasonable approximation of human nerve lesions5,4. Though smaller in size than rat nerve, the mouse nerve has many similar qualities. Most importantly though, mouse models are increasingly valuable because of the wide availability of transgenic lines now allows for a detailed dissection of the individual molecules critical for nerve regeneration6, 7. Prior investigators have used multiple methods to produce a nerve crush or injury including simple angled forceps, chilled forceps, hemostatic forceps, vascular clamps, and investigator-designed clamps8,9,10,11,12. Investigators have also used various methods of marking the injury site including suture, carbon particles and fluorescent beads13,14,1. We describe our method to obtain a reproducibly complete sciatic nerve crush with accurate and persistent marking of the crush-site using a fine hemostatic forceps and subsequent carbon crush-site marking. As part of our description of the sciatic nerve crush procedure we have also included a relatively simple method of muscle whole mount we use to subsequently quantify regeneration.

In this report we describe a method to crush mouse sciatic nerve. This method uses readily available hemostatic forceps and easily and reproducibly produces complete sciatic nerve crush. In addition, we describe a method to prepare muscle whole mounts suitable for analysis of nerve regeneration after sciatic nerve crush.

重复性小鼠坐骨神经挤压和再生的后续评估整装肌肉分析

Regeneration in the peripheral nervous system (PNS) is widely studied both for its relevance to human disease and to understand the robust regenerative ...

Optical Recording of Suprathreshold Neural Activity with Single-cell and Single-spike Resolution

Signaling of information in the vertebrate central nervous system is often carried by populations of neurons rather than individual neurons. Also propagation of suprathreshold spiking activity involves populations of neurons. Empirical studies addressing cortical function directly thus require recordings from populations of neurons with high resolution. Here we describe an optical method and a deconvolution algorithm to record neural activity from up to 100 neurons with single-cell and single-spike resolution. This method relies on detection of the transient increases in intracellular somatic calcium concentration associated with suprathreshold electrical spikes (action potentials) in cortical neurons. High temporal resolution of the optical recordings is achieved by a fast random-access scanning technique using acousto-optical deflectors (AODs)1. Two-photon excitation of the calcium-sensitive dye results in high spatial resolution in opaque brain tissue2. Reconstruction of spikes from the fluorescence calcium recordings is achieved by a maximum-likelihood method. Simultaneous electrophysiological and optical recordings indicate that our method reliably detects spikes (&gt;97% spike detection efficiency), has a low rate of false positive spike detection (&lt; 0.003 spikes/sec), and a high temporal precision (about 3 msec) 3. This optical method of spike detection can be used to record neural activity in vitro and in anesthetized animals in vivo3,4.

Understanding the function of the vertebrate central nervous system requires recordings from many neurons because cortical function arises on the level of populations of neurons. Here we describe an optical method to record suprathreshold neural activity with single-cell and single-spike resolution, dithered random-access scanning. This method records somatic fluorescence calcium signals from up to 100 neurons with high temporal resolution. A maximum-likelihood algorithm deconvolves the underlying suprathreshold neural activity from the somatic fluorescence calcium signals. This method reliably detects spikes with high detection efficiency and a low rate of false positives and can be used to study neural populations in vitro and in vivo.

阈上的神经活动的单细胞和单穗的分辨率的光学的方法记录

Signaling of information in the vertebrate central nervous system is often carried by populations of neurons rather than individual neurons. Also ...

Viral Tracing of Genetically Defined Neural Circuitry

Classical methods for studying neuronal circuits are fairly low throughput. Transsynaptic viruses, particularly the pseudorabies (PRV) and rabies virus (RABV), and more recently vesicular stomatitis virus (VSV), for studying circuitry, is becoming increasingly popular. These higher throughput methods use viruses that transmit between neurons in either the anterograde or retrograde direction.
Recently, a modified RABV for monosynaptic retrograde tracing was developed. (Figure 1A). In this method, the glycoprotein (G) gene is deleted from the viral genome, and resupplied only in targeted neurons. Infection specificity is achieved by substituting a chimeric G, composed of the extracellular domain of the ASLV-A glycoprotein and the cytoplasmic domain of the RABV-G (A/RG), for the normal RABV-G1. This chimeric G specifically infects cells expressing the TVA receptor1. The gene encoding TVA can been delivered by various methods2-8. Following RABV-G infection of a TVA-expressing neuron, the RABV can transmit to other, synaptically connected neurons in a retrograde direction by nature of its own G which was co-delivered with the TVA receptor. This technique labels a relatively large number of inputs (5-10%)2 onto a defined cell type, providing a sampling of all of the inputs onto a defined starter cell type.
We recently modified this technique to use VSV as a transsynaptic tracer9. VSV has several advantages, including the rapidity of gene expression. Here we detail a new viral tracing system using VSV useful for probing microcircuitry with increased resolution. While the original published strategies by Wickersham et al.4 and Beier et al.9 permit labeling of any neurons that project onto initially-infected TVA-expressing-cells, here VSV was engineered to transmit only to TVA-expressing cells (Figure 1B). The virus is first pseudotyped with RABV-G to permit infection of neurons downstream of TVA-expressing neurons. After infecting this first population of cells, the virus released can only infect TVA-expressing cells. Because the transsynaptic viral spread is limited to TVA-expressing cells, presence of absence of connectivity from defined cell types can be explored with high resolution. An experimental flow chart of these experiments is shown in Figure 2. Here we show a model circuit, that of direction-selectivity in the mouse retina. We examine the connectivity of starburst amacrine cells (SACs) to retinal ganglion cells (RGCs).

A method of tracing synaptically connected neurons is described. We use TVA specificity of an upstream cell to probe whether a cell population of interest receives synaptic input from genetically defined cell types.

病毒遗传背景明确的神经回路跟踪

Classical methods for studying neuronal circuits are fairly low throughput. Transsynaptic viruses, particularly the pseudorabies (PRV) and rabies virus ...

In vivo Optogenetic Stimulation of the Rodent Central Nervous System

The ability to probe defined neural circuits in awake, freely-moving animals with cell-type specificity, spatial precision, and high temporal resolution has been a long sought tool for neuroscientists in the systems-level search for the neural circuitry governing complex behavioral states. Optogenetics is a cutting-edge tool that is revolutionizing the field of neuroscience and represents one of the first systematic approaches to enable causal testing regarding the relation between neural signaling events and behavior. By combining optical and genetic approaches, neural signaling can be bi-directionally controlled through expression of light-sensitive ion channels (opsins) in mammalian cells. The current protocol describes delivery of specific wavelengths of light to opsin-expressing cells in deep brain structures of awake, freely-moving rodents for neural circuit modulation. Theoretical principles of light transmission as an experimental consideration are discussed in the context of performing in vivo optogenetic stimulation. The protocol details the design and construction of both simple and complex laser configurations and describes tethering strategies to permit simultaneous stimulation of multiple animals for high-throughput behavioral testing.

In vivo Optogenetic Stimulation of the Rodent Central Nervous System

Optogenetics has become a powerful tool for use in behavioral neuroscience experiments. This protocol offers a step-by-step guide to the design and set-up of laser systems, and provides a full protocol for carrying out multiple and simultaneous in vivo optogenetic stimulations compatible with most rodent behavioral testing paradigms.

在啮齿动物中枢神经系统的体内光遗传学刺激

The ability to probe defined neural circuits in awake, freely-moving animals with cell-type specificity, spatial precision, and high temporal resolution ...

Assessing Spatial Learning and Memory in Small Squamate Reptiles

Clinical research has leveraged a variety of paradigms to assess cognitive decline, commonly targeting spatial learning and memory abilities. However, interest in the cognitive processes of nonmodel species, typically within an ecological context, has also become an emerging field of study. In particular, interest in the cognitive processes in reptiles is growing although experimental studies on reptilian cognition are sparse. The few reptilian studies that have experimentally tested for spatial learning and memory have used rodent paradigms modified for use in reptiles. However, ecologically important aspects of the physiology and behavior of this taxonomic group must be taken into account when testing for spatially based cognition. Here, we describe modifications of the dry land Barnes maze and associated testing protocol that can improve performance when probing for spatial learning and memory ability in small squamate reptiles. The described paradigm and procedures were successfully used with male side-blotched lizards (Uta stansburiana), demonstrating that spatial learning and memory can be assessed in this taxonomic group with an ecologically relevant apparatus and protocol.

This paper describes a modification of the Barnes maze, a standard rodent paradigm used to assess spatial memory and learning, for use in small squamate reptiles.

评估空间学习记忆小鳞类爬行动物

Clinical research has leveraged a variety of paradigms to assess cognitive decline, commonly targeting spatial learning and memory abilities. However, ...

Recording EEG in Freely Moving Neonatal Rats Using a Novel Method

EEG is a useful method to detect electrical activity in the brain. Moreover, it is a widely used diagnostic tool for various neurological conditions, such as epilepsy and neurodegenerative disorders. However, it is technically difficult to obtain EEG recordings in neonates as it requires specialized handling and great care. Here, we present a novel method to record EEG in neonatal rat pups (P8-P15). We designed a simple and reliable electrode using computer pin loci; it can be easily implanted into the skull of a rat pup to record high-quality EEG signals in the normal and epileptic brain. Pups were given an intraperitoneal (i.p.) injection of the neurotoxin kainic acid (KA) to induce epileptic seizures. The surgical implantation performed in this procedure is less expensive than other EEG procedures for neonates. This method allows one to record high-quality and stable EEG signals for more than 1 week. Furthermore, this procedure can also be applied to adult rats and mice to study epilepsy or other neurological disorders.

Here, we introduce a novel technique designed to record electroencephalography (EEG) in freely moving neonatal epileptic pups and describe its procedures, features, and applications. This method allows one to record EEG for more than 1 week.

使用新颖的方法在自由移动的新生大鼠中记录脑电图

EEG is a useful method to detect electrical activity in the brain. Moreover, it is a widely used diagnostic tool for various neurological conditions, such ...

Drosophila Courtship Conditioning As a Measure of Learning and Memory

Many insights into the molecular mechanisms underlying learning and memory have been elucidated through the use of simple behavioral assays in model organisms such as the fruit fly, Drosophila melanogaster. Drosophila is useful for understanding the basic neurobiology underlying cognitive deficits resulting from mutations in genes associated with human cognitive disorders, such as intellectual disability (ID) and autism. This work describes a methodology for testing learning and memory using a classic paradigm in Drosophila known as courtship conditioning. Male flies court females using a distinct pattern of easily recognizable behaviors. Premated females are not receptive to mating and will reject the male&#39;s copulation attempts. In response to this rejection, male flies reduce their courtship behavior. This learned reduction in courtship behavior is measured over time, serving as an indicator of learning and memory. The basic numerical output of this assay is the courtship index (CI), which is defined as the percentage of time that a male spends courting during a 10 min interval. The learning index (LI) is the relative reduction of CI in flies that have been exposed to a premated female compared to na&#239;ve flies with no previous social encounters. For the statistical comparison of LIs between genotypes, a randomization test with bootstrapping is used. To illustrate how the assay can be used to address the role of a gene relating to learning and memory, the pan-neuronal knockdown of Dihydroxyacetone phosphate acyltransferase (Dhap-at) was characterized here. The human ortholog of Dhap-at, glyceronephosphate O-acyltransferase (GNPT), is involved in rhizomelic chondrodysplasia punctata type 2, an autosomal-recessive syndrome characterized by severe ID. Using the courtship conditioning assay, it was determined that Dhap-at is required for long-term memory, but not for short-term memory. This result serves as a basis for further investigation of the underlying molecular mechanisms.

Drosophila Courtship Conditioning As a Measure of Learning and Memory

This protocol describes a Drosophila learning and memory assay called courtship conditioning. This classic assay is based on a reduction of male courtship behavior after sexual rejection by a non-receptive premated female. This natural form of behavioral plasticity can be used to test learning, short-term memory, and long-term memory.

果蝇调理作为学习和记忆的措施

Many insights into the molecular mechanisms underlying learning and memory have been elucidated through the use of simple behavioral assays in model ...