This research was supported by a grant of the Korea Health Technology R&#38;D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health &#38; Welfare, Republic of Korea (grant number: H14C04660000).

All animal experiments were carried out in accordance with the National Institutes of Health Guide for the Care and Use of Laboratory Animals (NIH Publications No. 8023, revised 1978) and with the Animal Care and Use Committee of the Institutional Animal Care and Use Committee of KIST (Seoul, Korea).
1. Animal Preparation
<ol>
	<li>Prepare a group of 7-week-old male ICR mice (or C57BL/6).</li>
	<li>Let the mice go through an acclimation process for 3-7 days after transport to restore homeostasis. In general, pla...

<ol>
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J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Methods of Behavior Analysis in Neuroscience Frontiers in Neuroscience. , (2009).</li><li>Van Dam, D., De Deyn, P. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+in+the+drug+discovery+pipeline+for+Alzheimer's+disease.">Animal models in the drug discovery pipeline for Alzheimer's disease.</a> Br J Pharmacol. 164, 1285-1300 (2011).</li><li>Choi, J. W., Kim, H. Y., Jeon, M., Kim, D. J., Kim, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+access+to+highly+pure+beta-amyloid+peptide+by+optimized+solid-phase+synthesis.">Efficient access to highly pure beta-amyloid peptide by optimized solid-phase synthesis.</a> Amyloid. 19, 133-137 (2012).</li><li>Rahimi, F., Maiti, P., Bitan, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photo-induced+cross-linking+of+unmodified+proteins+(PICUP)+applied+to+amyloidogenic+peptides.">Photo-induced cross-linking of unmodified proteins (PICUP) applied to amyloidogenic peptides.</a> J Vis Exp. , (2009).</li><li>Kim, H. V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amelioration+of+Alzheimer's+disease+by+neuroprotective+effect+of+sulforaphane+in+animal+model.">Amelioration of Alzheimer's disease by neuroprotective effect of sulforaphane in animal model.</a> Amyloid. 20, 7-12 (2013).</li><li>Jackson, L. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=VTE+on+an+elevated+T-maze.">VTE on an elevated T-maze.</a> J Comp Psychol. 36, 9 (1943).</li><li>Kim, H. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Taurine+in+drinking+water+recovers+learning+and+memory+in+the+adult+APP/PS1+mouse+model+of+Alzheimer's+disease.">Taurine in drinking water recovers learning and memory in the adult APP/PS1 mouse model of Alzheimer's disease.</a> Sci Rep. 4, 7467 (2014).</li><li>Paxinos, G., Franklin, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Mouse Brain in Stereotaxic Coordinates. 2nd edn. , (2001).</li><li>Ledo, J. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amyloid-beta+oligomers+link+depressive-like+behavior+and+cognitive+deficits+in+mice.">Amyloid-beta oligomers link depressive-like behavior and cognitive deficits in mice.</a> Mol Psychiatry. 18, 1053-1054 (2013).</li><li>Laursen, S. E., Belknap, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracerebroventricular+injections+in+mice.+Some+methodological+refinements.">Intracerebroventricular injections in mice. Some methodological refinements.</a> J Pharmacol Methods. 16, 355-357 (1986).</li><li>Bromley-Brits, K., Deng, Y., Song, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morris+water+maze+test+for+learning+and+memory+deficits+in+Alzheimer's+disease+model+mice.">Morris water maze test for learning and memory deficits in Alzheimer's disease model mice.</a> J Vis Exp. , (2011).</li><li>Figueiredo, C. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Memantine+rescues+transient+cognitive+impairment+caused+by+high-molecular-weight+abeta+oligomers+but+not+the+persistent+impairment+induced+by+low-molecular-weight+oligomers.">Memantine rescues transient cognitive impairment caused by high-molecular-weight abeta oligomers but not the persistent impairment induced by low-molecular-weight oligomers.</a> J Neurosci. 33, 9626-9634 (2013).</li><li>Haley, T. J., McCormick, 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=Pharmacological+effects+produced+by+intracerebral+injection+of+drugs+in+the+conscious+mouse.">Pharmacological effects produced by intracerebral injection of drugs in the conscious mouse.</a> Br J Pharmacol Chemother. 12, 12-15 (1957).</li><li>Harkany, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroprotective+approaches+in+experimental+models+of+beta-amyloid+neurotoxicity:+relevance+to+Alzheimer's+disease.">Neuroprotective approaches in experimental models of beta-amyloid neurotoxicity: relevance to Alzheimer's disease.</a> Prog Neuropsychopharmacol Biol Psychiatry. 23, 963-1008 (1999).</li><li>Wang, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+allosteric+potentiation+of+nicotinic+acetylcholine+receptors+by+galantamine+ameliorates+the+cognitive+dysfunction+in+beta+amyloid25-35+i.c.v.-injected+mice:+involvement+of+dopaminergic+systems.">The allosteric potentiation of nicotinic acetylcholine receptors by galantamine ameliorates the cognitive dysfunction in beta amyloid25-35 i.c.v.-injected mice: involvement of dopaminergic systems.</a> Neuropsychopharmacology. 32, 1261-1271 (2007).</li><li>Yamada, K., Nabeshima, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+Alzheimer's+disease+and+evaluation+of+anti-dementia+drugs.">Animal models of Alzheimer's disease and evaluation of anti-dementia drugs.</a> Pharmacol Ther. 88, 93-113 (2000).</li><li>Cho, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Correlations+of+amyloid-beta+concentrations+between+CSF+and+plasma+in+acute+Alzheimer+mouse+model.">Correlations of amyloid-beta concentrations between CSF and plasma in acute Alzheimer mouse model.</a> Sci Rep. 4, 6777 (2014).</li></ol>

The authors have nothing to disclose.

The most important step in this protocol is the ICV injection of A&#946;. This protocol is designed to inject A&#946; into the ICV region of mice without stereotactic instruments11,12. Before starting an experiment, a preliminary period of practice injections with a blue dye instead of A&#946; should take place to achieve sufficient dexterity. Immediately after the injection, it is necessary to check whether the pigment injection was performed properly. Carefully take out the brain and check whether the approp...

Given that amyloid-&#946; (A&#946;) is a pathological hallmark of Alzheimer&#39;s disease (AD), the development of AD animal models has focused on neural overexpression of A&#946;. Because mutations in amyloid precursor protein (APP) or presenilin (PS) lead to disturbance of A&#946; equilibrium and ultimately to the pathogenesis of familial AD1, mouse models involving APP or PS gene mutations have been generally accepted. Among the wide range of transgenic mice, prototypical mouse models include the following: TG2576, PDAPP, APP/PS1 and APP23. In the brain, these mice generally exhibit A&#946; aggregation and eventually senile plaques; plaque formation is followed by significant cognitive impairment such that they show poor performance in behavioral tests of learning and memory. The generation of using transgenic mice that naturally mimic human AD pathology has thus contributed to AD research society by allowing us to monitor the progression of the disease. However, using transgenic mice is uneconomical and time-consuming because it takes months for the mice to develop A&#946; plaques and even longer to show A&#946;-induced synaptic or behavioral abnormalities2,3. Originally developed as an alternative to overcome the shortcomings of transgenic mouse models, non-transgenic models are also commonly used due to their distinct advantages. Pathogen-induced AD models can be produced by the direct injection of A&#946; into the brain, whereas AD-like cognitive deficits can also be triggered by other chemical and physical means-such as the injection of neurotoxic compounds such as scopolamine, the induction of lesions in cognition-related areas such as the hippocampus, or by cortical damage4. However, the non-pathogenic induction of cognitive impairment does not accurately reflect the fundamental pathophysiology of AD; instead, it only mimics its symptomatic outcomes. In contrast, a pathogen-induced AD model, the A&#946;-injected mouse model, can not only show AD-like behavioral abnormalities but can also exhibit A&#946; pathology, the common feature shared by familial and sporadic AD.
Despite the difficulty to visualize A&#946; plaques in the brain tissue, the largest benefit of the A&#946;-injected model that makes it attractive for AD investigation is its controllability. Researchers can weed out the individual differences in mouse models that can lead to erroneous data in drug-related studies. Timely drug treatment is enabled depending on the mechanism of the candidate drug; to elaborate, an inhibitor of A&#946; aggregation can be applied before the injection of A&#946;. Additionally, investigators can assume that the pathogenic transformation that arises after A&#946; injection is derived from the A&#946; exposure because the other factors are tightly controlled, including individual differences.
In this protocol, a vivid description of how to induce an AD-like phenotype in normal mice via A&#946; intracerebroventricular (ICV) injection without stereotactic instruments is presented. Minimizing insertion-provoked damage to brain tissue is essential to prevent the possibility of structural damage and lesion-induced inflammation. A lack of skill in mouse handling leads to unexpected neuronal injury. Furthermore, techniques that enable the appropriate angle and depth to be achieved during the injection are especially important to circumvent frequent mistakes. In addition to a detailed, vivid explanation of the ICV injection, the reliability of the model produced by the following protocol is also illustrated in the following sections. The following protocol could be a reliable and easily understood tool that contributes to AD research, thereby providing a steppingstone that could ultimately lead to a meaningful discovery for AD society.

<table border="0" cellpadding="0" cellspacing="0" width="1106">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:300px;">ICR mouse</td>
			<td style="width:155px;">Orientbio</td>
			<td style="width:119px;"></td>
			<td style="width:532px;">male, 6~8 weeks, 27~29 g of body weight</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">C57BL/6 mouse</td>
			<td>Orientbio</td>
			<td></td>
			<td>male, 6~8 weeks, 21~23 g of body weight</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Amyloid-beta1-42</td>
			<td>in house synthesis</td>
			<td>n.a.</td>
			<td>stock concentration: 1 mM/DMSO, injected concentration: 100 &#956;M/10% DMSO and 90% PBS</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">ICV injection syringe (26s gauge)</td>
			<td>Hamilton</td>
			<td>80308</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Evans blue dye (EBD)</td>
			<td>abcamBIochemicals</td>
			<td>ab120869</td>
			<td>1 % EBD in PBS</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">DMSO</td>
			<td>Sigma</td>
			<td>D2650</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">PBS</td>
			<td>gibco</td>
			<td>10010-023</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Gradi-GelTM II Gradient PAGE Analysis Kit</td>
			<td>ELPiS Biotech</td>
			<td>EBS-1056</td>
			<td>15% Gel</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Precision Plus ProteinTM Dual Xtra Standards</td>
			<td>Bio-Rad</td>
			<td>161-0377</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Silver-Staining Kit</td>
			<td>GE-Healthcare</td>
			<td>17-1150-01</td>
			<td></td>
		</tr>
	</tbody>
</table>

intracerebroventricular injection of amyloid-&#946; peptides in normal mice to acutely induce alzheimer-like cognitive deficits

Amyloid-&#946; (A&#946;) is a major pathological mediator of both familial and sporadic Alzheimer's disease (AD). In the brains of AD patients, progressive accumulation of A&#946; oligomers and plaques is observed. Such A&#946; abnormalities are believed to block long-term potentiation, impair synaptic function, and induce cognitive deficits. Clinical and experimental evidences have revealed that the acute increase of A&#946; levels in the brain allows development of Alzheimer-like phenotypes. Hence, a detailed protocol describing how to acutely generate an AD mouse model via the intracerebroventricular (ICV) injection of A&#946; is necessary in many cases. In this protocol, the steps of the experiment with an A&#946;-injected mouse are included, from the preparation of peptides to the testing of behavioral abnormalities. The process of preparing the tools and animal subjects before the injection, of injecting the A&#946; into the mouse brain via ICV injection, and of assessing the degree of cognitive impairment are easily explained throughout the protocol, with an emphasis on tips for effective ICV injection of A&#946;. By mimicking certain aspects of AD with a designated injection of A&#946;, researchers can bypass the aging process and focus on the downstream pathology of A&#946; abnormalities.

This section illustrates examples of the results that can be obtained by confirmation of A&#946; aggregation and Y-maze assessment of memory deficits. Using the full-length A&#946;(1-42) peptide of 42 amino acids, mixture of A&#946; monomers, oligomers, and fibrils (Figure 3) was produced. Through the HFIP-induced monomerization step, relatively homogeneous monomers (Lane B) were obtained. After the 7 day incubation, diverse sizes of A&#946; aggregates (Lane C) developed....

Watch this Scientific Journal Video about Intracerebroventricular Injection of Amyloid-Î² Peptides in Normal Mice to Acutely Induce Alzheimer-like Cognitive Deficits at JoVE.com

Intracerebroventricular Injection of Amyloid-&amp;#946; Peptides in Normal Mice to Acutely Induce Alzheimer-like Cognitive Deficits

The amyloid-&#946; (A&#946;)-injected animal model enables the administration of a defined quantity and species of A&#946; fragments and reduces individual differences within each study group. This protocol describes the intracerebroventricular (ICV) injection of A&#946; without stereotactic instruments, enabling the production of Alzheimer-like behavioral abnormalities in normal mice.

Intracerebroventricular Injection of Amyloid-&#946; Peptides in Normal Mice to Acutely Induce Alzheimer-like Cognitive Deficits

Amyloid-&#946; (A&#946;) is a major pathological mediator of both familial and sporadic Alzheimer's disease (AD). In the brains of AD patients, ...

The overall goal of this surgical procedure is to conduct the intracerebroventricular injection of Amyloid beta without stereotactic instruments, and to acutely induce Alzheimer-like behavior abnormalities in normal mice. This method can help answering key questions in the field of neurobiology, such as drug discovery for Alzheimer's Disease. The main benefit of this technique is that we can perform the direct injection of A beta into the intracerebroventricle region of the mice without the help of stereotactic instruments, and it allows us to mimic Alzheimer-like behavior abnormalities in mice without waiting for the aging process.The implications of this technique extend towards therapy or diagnosis of Alzheimer's Disease, because it can be used to study the downstream pathology of Amyloid beta, and screened for drug candidates. Generally, individual new to this method will struggle, because finding the precise location of bregma on animal skull may be difficult. To begin this procedure, make one millimolar A-beta with DMSO.Then, dilute it ten fold in PBS. Next, prepare PBS solution containing 10%DMSO as a vehicle for ICV injection. After that, wrap the microsyringe with a 26-gauge stainless steel needle using Parafilm strips in order to adjust the needle length for depth-controlled injection.Densely wrap the syringe multiple times so that the Parafilm will not be compressed during needle insertion, and the needle length stays constant. Then, cut the layers of Parafilm strips to adjust the needle length to 3.8 millimeters between the needle tip and the Parafilm. Next, wash the syringe twice with 70%ethanol.Subsequently, rinse the syringe with distilled water. Dry it completely in a fume hood for at least 30 minutes, and leave the clean syringe under a UV light for another 20 minutes before injection. In this step, place a seven week old anesthetized mouse on a warm mat.Next, apply sterile PBS drops or ointment to both eyes to prevent corneal dryness during the procedure. Afterward, confirm adequate anesthesia by assessing the toe pinch extensor withdrawal reflex. Then, prepare two mirrors with multiple vertical lines drawn on the surfaces to provide references for the syringe's perpendicular injection.Place one mirror right next to the body of the mouse, and the other in front of the head. Keep M1 parallel to the imaginary midline between the two eyes of the mouse and arrange M2 perpendicular to M1, so that the two planes form a 90 degree angle. Next, spray 70%ethanol on the mouse forehead, and rub it with dry cotton swabs.To locate the bregma, place the thumb and index fingers directly above the eyes and slightly press the forehead down to the extent that both eyes protrude. At the same time, drag the skin of the forehead backwards in order to minimize the skull movement under it. Locate the injection site with a tailor's tape at 2.4 millimeters depth under the skull.Fill the syringe with 10 microliters of A-beta solution or vehicle. Place the syringe so that it is perpendicular to the plane of the injection site. Then, align the reflected images of the syringe in both mirrors with the drawn lines on the mirrors.Begin inserting the needle until the Parafilm wrapping touches the skin. Hold the syringe with one hand, and inject five microliters of the A-beta solution or vehicle with the other hand, slowly over five seconds without pausing, and make sure the syringe remains perpendicular throughout. After completing the injection, wait three to five seconds before removing the syringe.Place the thumb and index fingers back on the head, and hold it down to prevent the skull from any unneccessary movements. Then remove the syringe without tilting. Subsequently, place the mouse on a warm pad for recovery.To confirm if A-beta was injected in the target ICV region, check the trace of the needle insertion in the brain tissue to see if it reached one of the ventricles. If the injection was unsuccessful, exclude that subject's data from analysis of the experimental results. In this experiment, the full-length A-beta peptide of 42 amino acids was used to produce a mixture of A beta monomers, oligomers, and fibrils.Through the HFIP induced monomerization step, relative homogenous monomers were obtained. After the seven day incubation, diverse sizes of A-beta aggregates were developed, in which trimers and tetramers were the dominant species among the oligomeric forms of A-beta. In this study, spacial working memory was assessed in the A-beta injected mice in the Y-maze test, in which the sequence of arm choices and the number of total arm entries were recorded while each mouse was allowed to freely explore the maze.The A-beta injected mouse group showed significantly lower alternation rates, indicating the development of cognitive deficits. Once mastered, this technique can be done in 20 minutes, including anesthetic procedures, if it is performed properly. While attempting these procedures, it is important to remember to make the needle perpendicular to the plane of injection.After its development, this technique paved the way for researchers in the field of drug discovery of Alzheimer's Disease to explore in vivo screening of drug candidates in these easily accessible Alzheimer's rodent models. After watching this video, you should have a good understanding of how to conduct intracerebroventricular injection without stereotactic instruments.

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40.9K visualizações.  Korea Institute of Science and Technology. The overall goal of this surgical procedure is to conduct the intracerebroventricular injection of Amyloid beta without stereotactic instruments, and to acutely induce Alzheimer-like behavior abnormalities in normal mice. This method can help answering key questions in the field of neurobiology, such as drug discovery for Alzheimer's Disease. The main benefit of this technique is that we can perform the direct injection of A beta into the intracerebroventricle region of the mice without the h...