Name: marble burying and nestlet shredding as tests of repetitive, compulsive-like behaviors in mice
Uploaded: 2013-12-24T13:45:00.000+00:00
Duration: 6 min 50 s
Description: Watch this Scientific Journal Video about Marble Burying and Nestlet Shredding as Tests of Repetitive, Compulsive-like Behaviors in Mice at JoVE.com

This work was supported by grants from the Department of Veterans Affairs and the National Institutes of Health.

All protocols using animals were carried out in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. The protocols were approved by the Institutional Care and Use Committee of Wayne State University (Permit Number A3310-01).
1.&#160;Preparation of Cages for Marble Burying and Nestlet Shredding
<ol>
	<li>Use standard polycarbonate rat cages (26 cm x 48 cm x 20 cm) with fitted filter-top covers for the marble burying test. Add fresh, unscented mouse bedding material to each cage to a depth of 5 cm and level bedding surface by inserting another cage of the same size onto the surface of the bedding. This has the added advantage of impressing a template of parallel lines on the bedding surface that can be used for marble placement.</li>
	<li>Place standard glass toy marbles (assorted styles and colors, 15 mm diameter, 5.2 g in weight) gently on the surface of the bedding in 5 rows of 4 marbles (see Figure 1A). Wash marbles in mild laboratory detergent, rinse exhaustively in distilled-deionized water, and dry prior to each use.</li>
	<li>Use standard polycarbonate rat cages (19 cm &#160;x 29 cm x 13 cm) with fitted filter-top covers for the nestlet shredding test. Add fresh, unscented mouse bedding material to each cage to a depth of 0.5 cm and pack bedding by insertion of another cage of the same size onto the surface of the bedding.</li>
	<li>Weigh commercially available cotton fiber nestlets (5 cm x 5 cm, 5 mm thick, ~2.5 g each) on an analytical balance and place one nestlet is placed on top of the bedding in each test cage (see Figure 3A).</li>
	<li>Set stop watches or timers for timing session lengths (30 min for each test).</li>
</ol>
2.&#160;Animal Handling Prior to Testing
<ol>
	<li>House mice individually or in groups in a room with a 12 hr light/dark cycle. Provide all mice with food and water ad libitum. Handle mice gently for three to five days prior to testing. Use mice of either sex for both tests.</li>
	<li>Perform behavioral testing between 9:00 am and 4:00 pm and transport all home cages containing mice to the testing room 60 min before the start of testing.</li>
</ol>
3.&#160;Marble Burying Test
<ol>
	<li>Place one mouse into a corner of the cage containing marbles, being careful to place the mouse on bedding as far from marbles as possible, and place the filter-top cover on the cage. Withhold food and water during the test. Allow mouse to remain in the cage undisturbed for 30 min.</li>
	<li>Remove the mouse and return it to its home cage after test completion, taking extreme care not to move or dislodge the marbles in the process of removing the subject from the cage.</li>
	<li>Task scorers (2-3) blind to the treatment conditions or genotype of the mouse being tested to count the number of marbles buried. Score a marble as buried if two-thirds of its surface area is covered by bedding. Average scores for the number of marbles buried for each mouse.</li>
	<li>Retrieve all 20 marbles from the bedding. Dispose of bedding.</li>
</ol>
4.&#160;Nestlet Shredding Test
<ol>
	<li>Place one mouse into a cage containing a single, preweighed nestlet and place the filter-top cover on the cage. Withhold food and water during the test. Leave mouse undisturbed in the cage with the nestlet for 30 min.</li>
	<li>Remove mouse and return to it to its home cage after test completion. Remove the remaining intact nestlet material from the cage with forceps and allow to dry O/N.</li>
	<li>Weigh remaining unshredded nestlet and divide this weight by the starting weight to calculate percentage&#160;of nestlet shredded. If desired, score the form of the nest produced by the subject mouse using a definitive 5-point nest rating scale17 but realizing that this scale is generally intended for scoring nest building, not obsessive-like shredding.</li>
	<li>Discard remaining shredded nestlet material and bedding.</li>
</ol>

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The authors declare that they have no competing financial interests.

The marble burying and nestlet shredding tests are good examples of behavioral methods for studying repetitive and compulsive-like behaviors in mice. Both tests show excellent face, construct and predictive validity for the human disorders they model6-11. These repetitive behaviors are natural and spontaneous in rodents and their frequency and intensity can vary after genetic modifications, as shown presently, or after head injury and treatment of subjects with drugs. The value of these two tests derives from the fact that they are validated models of human psychiatric disorders such as OCD and ASD, both of which involve expression of repetitive, unwanted behaviors. Both tests are robust and sensitive to large variations in the expression of digging, burying and shredding behaviors in mice, as illustrated by TPH2 KO mice.
With respect to existing methods (e.g.&#160;genetic, pharmacological, and neurodevelopment models) the marble burying and nestlet shredding tests have numerous advantages. Both are readily available to most labs without the need for sophisticated and expensive equipment. These tests are simple to apply, they can be formatted for high-throughput analyses and they are easy to score reliably. With slight modifications, these models can provide additional valuable information that can be useful when studying more complex behaviors and disorders. For instance, test sessions in both models can be video-taped and mice can be scored for locomotor activity, distance traveled, time spent moving, and percent of time spent in each region of the test cage (e.g.&#160;center versus perimeter). Measures such as these can provide revealing information on levels of anxiety, particularly if using subject mice with genetic manipulations that might be anxiogenic. Drug treatments can also modify repetitive behaviors indirectly by altering locomotor activity, so the parallel measure of this parameter along with marble burying or nestlet shredding could reveal drug-induced effects on movement.
One limitation of the marble burying test relates to the question of whether marble burying actually represents compulsive-like behavior or if the marbles evoke novelty-induced or anxiety-like responses in mice. Careful study has shown that the glass marbles do not serve as a fear- or anxiety-producing stimulus19,20 and attempts to habituate mice to the marbles do not change burying. It could also be argued that marble burying is actually secondary to digging and burrowing in rodents. Therefore, mice do not bury marbles specifically but in the process of digging and burrowing, marbles become covered by the bedding. This potential limitation can be tempered by the observation that digging correlates with burying and not with other behaviors emitted during this test19-21. Another limitation of marble burying is under-estimation of the behavior in animals that show excessive amounts of digging and burrowing (e.g.&#160;TPH2 KO mice). These mice dig intensely in the absence of any objects in the test cage16 and a similar situation could occur in other genetically modified mice or in subjects treated with certain drugs. Thus, it is likely that marbles are buried and subsequently uncovered, to be scored inaccurately as unburied. Finally, a limitation that applies to both the marble burying and nestlet shredding tests is the fact that mice will often climb on and hang from the wire cage tops. This competing behavior will diminish the amount of time spent in marble burying and nestlet shredding. This climbing behavior is natural in rodents and could represent a repetitive behavior as well. However, to avoid this potential problem, flat wire tops or filter-top covers can be used.
Modifications in the marble burying test can help overcome these possible limitations. First, test sessions can be video-captured but this modification would involve added work in post-session video review and analysis. Second, marbles and their initial locations can be marked individually so that their movement can be tracked after session completion. Third, analysis of the topographic changes in the bedding surface (i.e.&#160;size and number of troughs and peaks in bedding) can be assessed and applied as an adjunct to time spent digging.
A critical step for both protocols is the use of fresh bedding to minimize the influence of interfering olfactory cues from subject to subject. Marbles should be cleaned carefully before each test and marbles and nestlets should always be handled with gloves for the same reason. To the extent possible, flat wire cage covers or filter-top covers should be used with deeper cages so that mice cannot reach the wire covers and spend time climbing. In addition, cages should have a minimum size of 26 cm x 48 cm x 20 cm to allow even dispersion of the marbles so that mice can ambulate in the cage without stepping on the marbles. At the completion of marble burying sessions, mice must be removed carefully to avoid movement of the marbles prior to scoring. After the completion of the nestlet shredding test, it is critical to allow nestlets to dry before their post-session weights are measured to avoid under-estimation of shredding. Finally, both tests should be scored by observers blinded to any variables or treatment applied to the subjects under study (e.g.&#160;genotype of mice being compared, drug treatment).
In summary, the marble burying and nestlet shredding tests provide accurate and sensitive assays of repetitive and compulsive-like behaviors in rodents. Future applications should extend these tests to the screening of new treatments for human conditions such as OCD and ASDs. These tests would also be valuable in the assessment of repetitive behaviors after traumatic brain injury and exposure of animals to chronic stress because each of these conditions can engender compulsive-like behaviors in humans and animals alike.

Mouse models of human behaviors, and particularly psychiatric disorders, constitute important and essential experimental approaches to the study of disease mechanisms and to the development of new therapies. Many psychiatric illnesses remain extremely difficult to model in animals (e.g.&#160;schizophrenia). However, animals exhibit a large number of natural and distinctive behaviors that can readily be linked to similar behaviors in humans. Movement or locomotor activity is one example of a behavior in animals that has a counterpart in humans. Rodents often engage in a variety of repetitive behaviors and examples include grooming or digging. One psychiatric condition that involves the exhibition of recurrent and unwanted behaviors in humans is obsessive-compulsive disorder (OCD). Behaviors that are highly characteristic of OCD include checking, counting, and excessive washing or grooming. OCD is a highly prevalent (affects 1-3% of the population) and debilitating psychiatric disorder1. A large number of pharmacological and behavioral approaches have been used to treat OCD. Many of these fall short of providing long-term relief and relapse is common at the end of a treatment regimen2,3. Another psychiatric condition that involves the expression repetitive behaviors is autism spectrum disorder (ASD). ASDs are characterized by deficits in communication and social interaction&#160;and repetitive, stereotyped behaviors to include spinning, rocking, finger flicking&#160;or flapping, and complex body movements. The Centers for Disease Control and Prevention has estimated that about 1 in 88 children are diagnosed with ASDs. Treatment options for this disorder are extremely limited in number and efficacy4,5. The intensity and frequency of occurrence of repetitive behaviors in OCD and ASD can become great enough to displace most other normal behaviors and social interactions in patients with these conditions. In light of the prevalence and debilitating nature of psychiatric conditions characterized by repetitive behaviors, and considering the poor understanding of their causes and limited treatment options, the use of animal models to study these behaviors takes on added urgency.
A large number of animal models of repetitive behaviors as seen in OCD and ASDs have been developed over the past 30 years and numerous excellent reviews describing these models have been published6-14. In general, these established models can be classified as genetic, pharmacological, neurodevelopmental and behavioral and most show good face, construct and predictive validity6,7. We have used two behavioral models- marble burying and nestlet shredding- to assess repetitive behaviors in mice genetically depleted of serotonin15,16. These methods have numerous advantages not the least of which are their ease of use, the accuracy with which the behaviors can be scored, the spontaneous exhibition of these behaviors in rodents, and their use in high-throughput screening of genetically modified mice for abnormal behavioral phenotypes. Furthermore, each test is carried out in standard and familiar rodent housing cages containing the same bedding used in subjects&#39; home cages, minimizing the need for habituation of mice to novel testing chambers. Food and/or water restriction are not required to &#34;motivate&#34; mice to perform. The marble burying test takes advantage of the proclivity of mice to dig in natural settings (e.g.&#160;burrows, escape tunnels) and in standard cage bedding, and the nestlet shred test capitalizes on the fact that mice are nesting animals by nature that build nests for protection of themselves and their offspring against environmental conditions (e.g.&#160;sound, light, temperature). Using nonspecialized and commonly available rodent housing materials, the marble burying and nestlet shredding tasks are simple and powerful behavioral assays of repetitive, compulsive-like behaviors in mice.

<table><tbody><tr><td>Glass toy marbles</td><td>local toy store</td><td>N/A</td><td>assorted styles, colors, clear, and opaque</td></tr><tr><td>Nestlets</td><td>Ancare</td><td>NES3600</td><td></td></tr><tr><td>N10 series mouse cage</td><td>Ancare</td><td>N10HT</td><td>standard rodent cage with wire top</td></tr><tr><td>R20 series rat cage</td><td>Ancare</td><td>R20</td><td>standard rodent cage with wire top</td></tr><tr><td>Bed-o&#039;Cobs</td><td>The Andersons</td><td>8B</td><td>standard rodent bulk bedding, 1/8 in</td></tr></tbody></table>

marble burying and nestlet shredding as tests of repetitive, compulsive-like behaviors in mice

Obsessive-compulsive disorder (OCD) and autism spectrum disorders (ASD) are serious and debilitating psychiatric conditions and each constitutes a significant public health concern, particularly in children. Both of these conditions are highlighted by the repeated expression of meaningless behaviors. Individuals with OCD often show checking, frequent hand washing, and counting. Children with ASDs also engage in repetitive tapping, arm or hand flapping, and rocking. These behaviors can vary widely in intensity and frequency of expression. More intense forms of repetitive behaviors can even result in injury (e.g.&#160;excessive grooming, hand washing, and self-stimulation). These behaviors are therefore very disruptive and make normal social discourse difficult. Treatment options for repetitive behaviors in OCD and ASDs are somewhat limited and there is great interest in developing more effective therapies for each condition. Numerous animal models for evaluating compulsive-like behaviors have been developed over the past three decades. Perhaps the animal models with the greatest validity and ease of use are the marble burying test and the nestlet shredding test. Both tests take advantage of the fact that the target behaviors occur spontaneously in mice. In the marble burying test, 20 marbles are arrayed on the surface of clean bedding. The number of marbles buried in a 30 min session is scored by investigators blind to the treatment or status of the subjects. In the nestlet shredding test, a nestlet comprised of pulped cotton fiber is preweighed and placed on top of cage bedding and the amount of the nestlet remaining intact after a 30 min test session is determined. Presently, we describe protocols for and show movie documentation of marble burying and nestlet shredding. Both tests are easily and accurately scored and each is sensitive to small changes in the expression of compulsive-like behaviors that result from genetic manipulations, disease, or head injury.

A primary advantage of the marble burying and nestlet shredding tests is the fact that each depends on natural and spontaneous behaviors of mice that can be quantified after test completion, allowing a single investigator to set up an experiment and then remain outside of the testing room until sessions end. A critical component of the marble burying test is the careful removal of the subject from the cage after testing. Mice typically attempt to avoid capture and, in the process, can dislodge or move marbles that were partially buried or partially bury marbles that were not buried at the end of the test session. Figure 1A shows a test cage just prior to introduction of a subject, as viewed from above. We prefer a precise alignment of marbles in this fashion which can subsequently be used to track movement of the marbles, in addition to burying (if desired). In an illustrative experiment, we compared marble burying by wild type (WT) mice to mice lacking the gene for tryptophan hydroxylase 2 (TPH2), the initial and rate limiting enzyme in the biosynthesis of brain serotonin (5HT). As a result of the null mutation in the gene for TPH2, these mice have no measureable brain 5HT15,16,18. These mice show a very interesting behavioral phenotype characterized primarily by repetitive, compulsive-like digging and burying15,16. Figure 1B shows a representative cage from WT mice and Figure 1C is a cage from a TPH2 knockout (KO) mouse after burying. The cage of the WT mouse is typical and shows few marbles buried (N = 3 in this example) and little displacement from their original locations. On the other hand, the TPH2 KO cage shows significant numbers of buried marbles (N = 17 in this example; unburied marbles marked with arrows) and an extensive displacement of marbles from their initial locations. The appearance of the bedding surface is also indicative of burying and digging behavior. Figure 1D, as viewed along the surface of the bedding, shows a level bedding surface prior to testing. Figure 1E shows that bedding also remains relatively undisturbed by a WT mouse. In contrast, Figure 1F shows a typical cage from a TPH2 KO mouse after the test session with a very undulating surface and deep troughs and peaks throughout the cage. Figure 2 (reprinted from Angoa-Pérez et al.15 with permission from Wiley) illustrates the principal result of this test which is simply the number of marbles buried. Clearly, the TPH2 KO mice buried significantly more marbles than their WT counterparts (13 versus 4 out of 20, respectively). Perhaps the one challenge in scoring this test is the definition of a buried marble. In this test, a marble is scored as buried if two-thirds of its surface is covered by bedding10. WT mice bury few marbles, so scoring them is generally not a problem. However, we find that TPH2 KO mice not only bury marbles but move large amounts of bedding around the cage as they burrow and dig, making scoring a greater challenge. Because this scoring is somewhat subjective, we use 2-3 independent scorers who are blind to the genotype or treatment of the test mice. As long as marbles are not accidentally displaced when test subjects are removed from the cage, the marble burying test is a robust and sensitive method for the analysis of repetitive, compulsive-like behaviors in normal mice and in mice that have been genetically modified. The usefulness of this test for assessing the effects of numerous classes of drugs on repetitive behaviors has also been established6,7,10.
Nestlet shredding is another test that takes advantage of the natural proclivity of mice to shred practically any material for nest construction. Males and female mice are both reliable shredders. As in the marble burying test, a single investigator can set up large numbers of test cages and then leave the test room for the duration of the test session. Figures 3A and 3B show two cages from WT mice after conclusion of the test. The nestlets in Figures 3A and 3B were 11% and 27% shredded, respectively. Figures 3C and 3D show representative nestlets from two TPH2 KO mice and show that nestlets are much more extensively shredded (i.e. 51% and 100% shredded in Figures 3C and 3D, respectively). Because nestlets are carefully weighted before placement into the cage, the analytical task in this test is to weigh the remainder of the intact nestlet after test completion to quantify the amount of nestlet shredded. In our experience, two issues can slightly complicate weighing of the nestlets after shredding. First, if the nestlets are even slightly moist, the weight of the remaining nestlet will be artificially high. To avoid this situation, we allow shredded nestlets to dry O/N to remove any moisture and we withhold food and water bottles (as sources of moisture) from cages during the test. Second, the shredded nestlets are not always as "cleanly" or totally shredded as in Figure 3D. It can be seen that some nestlets contain adherent material that has clearly been shredded from the main body of the nestlet, but is still clinging to the intact part. As in the marble burying test, we use 2-3 raters to judge the amount of adherent but shredded material that should not be considered part of the remaining intact nestlet. This material is then carefully teased away from the intact nestlet with forceps and the remaining unshredded portion is weighed. An example of this condition is presented in the inset to Figure 3A with arrows pointing to material that should be removed prior to weighing or the remaining nestlet. Figure 4 (reprinted from Angoa-Pérez et al.15 with permission from Wiley) illustrates a representative outcome of nestlet shredding when comparing WT mice to TPH2 KO mice. It can be seen that TPH2 KO mice show significantly more shredding than WT controls (~ 50% versus 10% shredded, respectfully). The nestlet shredding test is a simple yet robust and sensitive method for assaying repetitive, compulsive-like behaviors in mice. Nestlet shredding is also a good compliment to the marble burying test and its effectiveness in testing a wide variety of drugs for their effects on repetitive behaviors has been well established10.
<img alt="Granular convection experiment; seed sifting; diagrams A-F show bead distribution and layers evolving." fo:content-width="3in" fo:src="/files/ftp_upload/50978/50978fig1highres.jpg" src="/files/ftp_upload/50978/50978fig1.jpg" data-altupdatedat="1747911167000" data-alt="Figure 1"> 
Figure 1. These photographs show representative cages before and after the marble burying test using WT and TPH2 KO mice as subjects. Panels A-C are photographed from above the cages and panels D-F are photographed along the surface of each cage. A) An example of a typical cage prior to introduction of a test subject, showing initial marble alignment; B) An example of a representative cage from a WT mouse after burying. In this example, few marbles are buried (N = 3) or displaced from their initial location; C) An example of a typical cage after testing a TPH2 KO mouse showing that 17 of the 20 marbles were buried in this case. Unburied marbles are indicated with arrows; D) A view of the bedding surface before introduction of a test mouse; E) An example of alterations in the bedding surface after removal of the WT mouse and F) An example of the bedding surface after testing a TPH2 KO mouse. The photograph in panel F cannot fully demonstrate in two-dimensions the disruption of the bedding material caused by the TPH2 KO mouse. Not only have most marbles been buried, the surface of the bedding appears to have been excavated by the TPH2 KO mouse. Areas of large troughs and peaks are clearly visible and it is typically the case that mice will dig and displace all bedding from one corner of the cage.
<a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50978/50978fig1highres.jpg" target="_blank">Click here to view larger image</a>.
<img alt="Bar chart showing marble burying, comparing WT and KO, behavioral experiment results." fo:content-width="4in" fo:src="/files/ftp_upload/50978/50978fig2highres.jpg" src="/files/ftp_upload/50978/50978fig2.jpg" data-altupdatedat="1747911167000" data-alt="Figure 2"> 
Figure 2. This graph shows typical performance of WT and TPH2 KO mice on the marble burying test. Observers blind to the genotype of test mice score each cage for the number of marbles buried (i.e. two-thirds of their surface covered with bedding). The scores for each test subject are averaged for all scorers and plotted as number of marbles buried versus mouse genotype. TPH2 KO mice (N= 20; 10 males and 10 females) bury significantly (two-way ANOVA, F1,66 = 35.61, p &lt;0.05; comparing sex and genotype) more marbles than WT mice (N= 37; 26 males and 11 females). Males and females did not differ in marble burying so data was combined across this variable within each genotype. Results are mean ± standard error of the mean. *** indicates p &lt;0.001 for Bonferroni post hoc comparisons between WT and KO mice. This figure is reprinted from Angoa-Pérez et al.15 with the permission of Wiley.
<a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50978/50978fig2highres.jpg" target="_blank">Click here to view larger image</a>.
<img alt="Cotton decomposition experiment; images A-D show decay stages on soil over time." fo:content-width="5in" fo:src="/files/ftp_upload/50978/50978fig3highres.jpg" src="/files/ftp_upload/50978/50978fig3.jpg" data-altupdatedat="1747911167000" data-alt="Figure 3"> 
Figure 3. These photographs show representative nestlets after shredding. A) and B) Examples of nestlets from 2 male WT mice showing minor amounts of shredding (i.e. 11% and 27% shredded in A and B, respectively, in these examples); C) and D) Examples of nestlets from 2 male TPH2 KO mice showing greater amounts of shredding (51% and 100% shredded in C and D, respectively, in these examples). Note in some cases that shredded material remains adherent to the main body of the unshredded nestlet (see inset to panel A). We use 2-3 scorers to judge the amount of shredded material that can be removed from the unshredded remainder of the nestlet. After this material is removed carefully, the remaining unshredded nestlet is weighed.
<a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50978/50978fig3highres.jpg" target="_blank">Click here to view larger image</a>.
<img alt="Nestlet shredding comparison graph, WT vs KO, bar chart, behavioral study results." fo:content-width="5in" fo:src="/files/ftp_upload/50978/50978fig4highres.jpg" src="/files/ftp_upload/50978/50978fig4.jpg" data-altupdatedat="1747911167000" data-alt="Figure 4"> 
Figure 4. This graph shows typical performance of WT and TPH2 KO mice on the nestlet shredding test. The weight of the remaining unshredded nestlet is divided by its initial weight to calculate the percentage of nestlet shredded and plotted versus mouse genotype. The TPH2 KO mice (N = 6 male mice) shred significantly (Student's t-test, t10 = 3.07, p &lt;0.05) more nestlet material than WT mice (N = 6 male mice). Results are mean ± standard error of the mean. * indicates p &lt;0.05. This figure is reprinted from Angoa-Pérez et al.15 with the permission of Wiley.
<a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50978/50978fig4highres.jpg" target="_blank">Click here to view larger image</a>.

Watch this Scientific Journal Video about Marble Burying and Nestlet Shredding as Tests of Repetitive, Compulsive-like Behaviors in Mice at JoVE.com

Marble Burying and Nestlet Shredding as Tests of Repetitive, Compulsive-like Behaviors in Mice

Disease, head injury, genetic modifications, and treatment of mice with drugs can have profound effects on behavior. Utilizing well-characterized and validated approaches such as marble burying and nestlet shredding, compulsive-like behaviors can be documented accurately in mice as models of human obsessive-compulsive disorder and autism spectrum disorder.

Obsessive-compulsive disorder (OCD) and autism spectrum disorders (ASD) are serious and debilitating psychiatric conditions and each constitutes a ...

marble-burying-nestlet-shredding-as-tests-repetitive-compulsive-like

Nanyang Technological University

Research

JoVE Journal

Behavior

28.2K 조회수.  Wayne State University School of Medicine. Disease, head injury, genetic modifications, and treatment of mice with drugs can have profound effects on behavior. Utilizing well-characterized and validated approaches such as marble burying and nestlet shredding, compulsive-like behaviors can be documented accurately in mice as models of human obsessive-compulsive disorder and autism spectrum disorder.

비디오: Marble Burying and Nestlet Shredding as Tests of Repetitive, Compulsive-like Behaviors in Mice

Inchworming: A Novel Motor Stereotypy in the BTBR T+ Itpr3tf/J Mouse Model of Autism

Autism Spectrum Disorder (ASD) is a behaviorally defined neurodevelopmental disorder characterized by decreased reciprocal social interaction, abnormal communication, and repetitive behaviors with restricted interest. As diagnosis is based on clinical criteria, any potentially relevant rodent models of this heterogeneous disorder should ideally recapitulate these diverse behavioral traits. The BTBR T+ Itpr3tf/J (BTBR) mouse is an established animal model of ASD, displaying repetitive behaviors such as increased grooming, as well as cognitive inflexibility. With respect to social interaction and interest, the juvenile play test has been employed in multiple rodent models of ASD. Here, we show that when BTBR mice are tested in a juvenile social interaction enclosure containing sawdust bedding, they display a repetitive synchronous digging motion. This repetitive motor behavior, referred to as &#34;inchworming,&#34; was named because of the stereotypic nature of the movements exhibited by the mice while moving horizontally across the floor. Inchworming mice must use their fore- and hind-limbs in synchrony to displace the bedding, performing a minimum of one inward and one outward motion. Although both BTBR and C56BL/6J (B6) mice exhibit this behavior, BTBR mice demonstrate a significantly higher duration and frequency of inchworming and a decreased latency to initiate inchworming when placed in a bedded enclosure. We conclude that this newly described behavior provides a measure of a repetitive motor stereotypy that can be easily measured in animal models of ASD.

Inchworming: A Novel Motor Stereotypy in the BTBR T+ Itpr3tf/J Mouse Model of Autism

Inchworming is a highly repetitive synchronous digging motion displayed by BTBR T+ Itpr3tf/J (BTBR) mice when placed in a testing cage with sufficient sawdust bedding. The procedure is a modification of the juvenile social interaction protocol and is used here to assess repetitive motor stereotypies relevant to Autism Spectrum Disorder.

Inchworming : BTBR의 소설 모터 상동증 (stereotypy)을<em&gt; T<sup&gt; +</sup&gt; Itpr3<sup&gt; TF</sup</em자폐증의&gt; / J 마우스 모델

Autism Spectrum Disorder (ASD) is a behaviorally defined neurodevelopmental disorder characterized by decreased reciprocal social interaction, abnormal ...

연구

행동분석학

Assessing Burrowing, Nest Construction, and Hoarding in Mice

Deterioration in the ability to perform "Activities of daily living" (ADL) is an early sign of Alzheimer's disease (AD). Preclinical behavioural screening of possible treatments for AD currently largely focuses on cognitive testing, which frequently demands expensive equipment and lots of experimenter time. However, human episodic memory (the most severely affected aspect of memory in AD) is different to rodent memory, which seems to be largely non-episodic. Therefore the present ways of screening for new AD treatments for AD in rodents are intrinsically unlikely to succeed. A new approach to preclinical screening would be to characterise the ADL of mice. Fortuitously, several such assays have recently been developed at Oxford, and here the three most sensitive and well-characterised are presented.
Burrowing was first developed in Oxford13. It evolved from a need to develop a mouse hoarding paradigm. Most published rodent hoarding paradigms required a distant food source to be linked to the home cage by a connecting passage. This would involve modifying the home cage as well as making a mouse-proof connecting passage and food source. So it was considered whether it would be possible to put the food source inside the cage. It was found that if a container was placed on the floor it was emptied by the next morning., The food pellets were, however, simply deposited in a heap at the container entrance, rather than placed in a discrete place away from the container, as might be expected if the mice were truly hoarding them. Close inspection showed that the mice were performing digging ("burrowing") movements, not carrying the pellets in their mouths to a selected place as they would if truly hoarding them.6



Food pellets are not an essential substrate for burrowing; mice will empty tubes filled with sand, gravel, even soiled bedding from their own cage. Moreover, they will empty a full tube even if an empty one is placed next to it8.



Several nesting protocols exist in the literature. The present Oxford one simplifies the procedure and has a well-defined scoring system for nest quality5. 



A hoarding paradigm was later developed in which the mice, rather than hoarding back to the real home cage, were adapted to living in the "home base" of a hoarding apparatus. This home base was connected to a tube made of wire mesh, the distal end of which contained the food source. This arrangement proved to yield good hoarding behaviour, as long as the mice were adapted to living in the "home base" during the day and only allowed to enter the hoarding tube at night.

Burrowing, nesting, and hoarding are species-typical activities that mice readily perform in the laboratory. This article describes how they can be easily and cheaply assessed. These protocols are extremely sensitive to mouse strain, brain lesions and diseases. Moreover they constitute &#x201C;environmental enrichment&#x201D; for the mice, and embody the &#x201C;Refinement&#x201D; aspect of the &#x201C;3 Rs&#x201D;18.

평가는 마우스에 둥지 건설, 그리고 비장을내는

Deterioration in the ability to perform "Activities of daily living" (ADL) is an early sign of Alzheimer's disease (AD). Preclinical behavioural screening ...

신경과학

Novel Object Exploration as a Potential Assay for Higher Order Repetitive Behaviors in Mice

Restricted, repetitive behaviors (RRBs) are a core feature of autism spectrum disorder (ASD) and disrupt the lives of affected individuals. RRBs are commonly split into lower-order and higher-order components, with lower order RRBs consisting of motor stereotypies and higher order RRBs consisting of perseverative and sequencing behaviors. Higher order RRBs are challenging to model in mice. Current assays for RRBs in mice focus primarily on the lower order components, making basic biomedical research into potential treatments or interventions for higher-order RRBs difficult. Here we describe a new assay, novel object exploration. This assay uses a basic open-field arena with four novel objects placed around the perimeter. The test mouse is allowed to freely explore the arena and the order in which the mouse investigates the novel objects is recorded. From these data, patterned sequences of exploration can be identified, as can the most preferred object for each mouse. The representative data shared here and past results using the novel object exploration assay illustrate that inbred mouse strains do demonstrate different behavior in this assay and that strains with elevated lower order RRBs also show elevated patterned behavior. As such, the novel object exploration assay appears to possess good face validity for higher order RRBs in humans and may be a valuable assay for future studies investigating novel therapeutics for ASD.

Higher order restricted, repetitive behaviors (RRBs) disrupt the lives of affected individuals. These behaviors are challenging to model in rodents, making basic biomedical research into potential treatments or interventions for RRBs difficult. Here we describe novel object exploration as a potential assay for higher order RRBs in mice.

마우스의 높은 주문 반복적 인 행동에 대한 잠재적 인 분석으로 소설 개체 탐사

Restricted, repetitive behaviors (RRBs) are a core feature of autism spectrum disorder (ASD) and disrupt the lives of affected individuals.  RRBs are ...

Systematic Assessment of Well-Being in Mice for Procedures Using General Anesthesia

In keeping with the 3R Principle (Replacement, Reduction, Refinement) developed by Russel and Burch, scientific research should use alternatives to animal experimentation whenever possible. When there is no alternative to animal experimentation, the total number of laboratory animals used should be the minimum needed to obtain valuable data. Moreover, appropriate refinement measures should be applied to minimize pain, suffering, and distress accompanying the experimental procedure. The categories used to classify the degree of pain, suffering, and distress are non-recovery, mild, moderate, or severe (EU Directive 2010/63). To determine which categories apply in individual cases, it is crucial to use scientifically sound tools.
The well-being-assessment protocol presented here is designed for procedures during which general anesthesia is used. The protocol focuses on home cage activity, the Mouse Grimace Scale, and luxury behaviors such as burrowing and nest building behavior as indicators of well-being. It also uses the free exploratory paradigm for trait anxiety-related behavior. Fecal corticosterone metabolites as indicators of acute stress are measured over the 24-h post-anesthetic period.
The protocol provides scientifically solid information on the well-being of mice following general anesthesia. Due to its simplicity, the protocol can easily be adapted and integrated in a planned study. Although it does not provide a scale to classify distress in categories according to the EU Directive 2010/63, it can help researchers estimate the degree of severity of a procedure using scientifically sound data. It provides a way to improve the assessment of well-being in a scientific, animal-centered manner.

We developed a protocol to assess well-being in mice during procedures using general anesthesia. A series of behavioral parameters indicating levels of well-being as well as glucocorticoid metabolites were analyzed. The protocol can serve as a general aid to estimate the degree of severity in a scientific, animal-centered manner.

일반 마 취 기계를 사용 하 여 프로시저에 대 한 마우스에 웰빙의 체계적인 평가

In keeping with the 3R Principle (Replacement, Reduction, Refinement) developed by Russel and Burch, scientific research should use alternatives to animal ...

A Behavioral Test Battery for the Repeated Assessment of Motor Skills, Mood, and Cognition in Mice

Pharmacological and toxicological studies in neurodegeneration require comprehensive behavioral analysis in mice because motor dysfunctions and dysfunctions in mood and cognition are common and often shared symptoms in neurodegenerative diseases. Shown here is a behavioral test battery for motor, mood, and cognition, which can be repeatedly tested in a longitudinal study. This battery assesses the overall behavioral phenotype in mice by examining each domain of behavior with at least two independent well-accepted tests (i.e., open-field test and rotarod test for motor function, social interaction test, elevated plus maze test, and forced swim test for emotional function, and Morris water maze test and novel object recognition test for cognitive function). Therefore, this sensitive and comprehensive test battery is a powerful tool for the study of behavioral alternation in neurodegeneration.

A comprehensive behavioral test battery of motor skills, mood&#8212;including social interaction, depression, and anxiety&#8212;and cognition is designed for the repeated assessment of neurodegeneration-related behavioral changes in mice.

모터 기술, 분위기, 그리고 쥐에 있는 인식의 반복 된 평가 행동 테스트 배터리

Pharmacological and toxicological studies in neurodegeneration require comprehensive behavioral analysis in mice because motor dysfunctions and ...

A Low-Cost, Odor-Reward Association Task for Tests of Learning and Memory

Robust and simple behavioral paradigms of appetitive, associative memory are crucial for researchers interested in cellular and molecular mechanisms of memory. In this paper, an effective and low-cost mouse behavioral protocol is described for examining the effects of physiological manipulation (such as the infusion of pharmacological agents) on the learning rate and duration of odor-reward memory. Representative results are provided from a study examining the differential role of tyrosine kinase receptor activity in short-term (STM) and long-term memory (LTM). Male mice were conditioned to associate a reward (sugar pellet) with one of the two odors, and their memory for the association was tested 2 or 48 h later. Immediately prior to the training, a tyrosine kinase (Trk) receptor inhibitor or vehicle infusions were delivered into the olfactory bulb (OB). Although there was no effect of the infusion on the learning rate, blockade of the Trk receptors in the OB selectively impaired LTM (48 h), and not short-term memory (STM; 2 h). The LTM impairment was attributed to the diminished odor selectivity as measured by the length of the digging time. The culmination of the results of this experiment showed that Trk receptor activation in the OB is the key in olfactory memory consolidation.

An odor-reward, associative learning task was used to investigate the differential effects of physiological manipulation on long-term and short-term memory.

Robust and simple behavioral paradigms of appetitive, associative memory are crucial for researchers interested in cellular and molecular mechanisms of ...

Nest Building Behavior as an Early Indicator of Behavioral Deficits in Mice

Nest building is an innate behavior in male and female rodents, even when raised in laboratory settings. As such, many researchers provide rodents synthetic and/or natural materials (such as twine, tissue, cotton, paper, and hay) as a gauge of their overall well-being and as an ancillary assessment to predict the possible decline in cognition. Typically, changes in nesting behaviors, such as failure to create a nest, indicate a change in health or welfare. In addition, nesting behavior is sensitive to many environmental and physiological challenges, as well as many genetic mutations underlying pathological disease states. The following protocol describes a nesting behavior paradigm that explores the usage of four types of nesting material. In addition, the protocol utilizes intraclass correlations to demonstrate that inter-rater reliability is higher when nests are constructed out of shredded paper compared to other common nesting materials such as cotton squares, paper twists, and soft cob bedding. The chosen methodology and statistical considerations (i.e., intraclass correlation) for this assay may be of interest for those conducting experiments assessing the quality of living of mice.&#160;

Here, we present a protocol to quantify nest building behavior in mice, which is known to be impaired in several neurological disorders and diseases. This protocol examines the utility of four materials and offers the opportunity to quantify the rater agreement in scoring, improving the validity and reliability of the assay.

마우스의 행동 적자의 초기 지표로 둥지 건물 행동

Nest building is an innate behavior in male and female rodents, even when raised in laboratory settings. As such, many researchers provide rodents ...

행동 테스트를 사용하여 Angelman Syndrome의 Murine 모델 검증

Behavioral Characterization of an Angelman Syndrome Mouse Model

This manuscript describes a battery of behavioral tests available to characterize Angelman syndrome (AS)-like phenotypes in an established murine model of AS. We use the rotarod learning paradigm, detailed gait analysis, and nest building test to detect and characterize animal motor impairments. We test animal emotionality in the open field and elevated plus maze tests, as well as the affect in the tail suspension test. When AS mice are tested in the open field test, the results should be interpreted with care, since motor dysfunctions influence mouse behavior in the maze and alter activity scores.
The reproducibility and effectiveness of the presented behavioral tests has already been validated in several independent Uba3a mouse lines with different knockout variants, establishing this set of tests as an excellent validation tool in AS research. Models with the relevant construct and face validity will warrant further investigations to elucidate the pathophysiology of the disease and grant the development of causal treatments.

저자 스포트라이트: Angelman Syndrome 쥐 모델을 검증하기 위한 고도로 재현 가능한 행동 테스트 배터리 

This manuscript presents a set of highly reproducible behavioral tests to validate an Angelman syndrome mouse model.

Angelman 증후군 마우스 모델의 행동 특성

This manuscript describes a battery of behavioral tests available to characterize Angelman syndrome (AS)-like phenotypes in an established murine model of ...

Marble Burying and Nestlet Shredding as Tests of Repetitive, Compulsive-like Behaviors in Mice

요약

더 많은 비디오 탐색

이 비디오의 챕터

Inchworming : BTBR의 소설 모터 상동증 (stereotypy)을

평가는 마우스에 둥지 건설, 그리고 비장을내는

마우스의 높은 주문 반복적 인 행동에 대한 잠재적 인 분석으로 소설 개체 탐사

일반 마 취 기계를 사용 하 여 프로시저에 대 한 마우스에 웰빙의 체계적인 평가

모터 기술, 분위기, 그리고 쥐에 있는 인식의 반복 된 평가 행동 테스트 배터리

A Low-Cost, Odor-Reward Association Task for Tests of Learning and Memory

마우스의 행동 적자의 초기 지표로 둥지 건물 행동

Angelman 증후군 마우스 모델의 행동 특성

Angelman 증후군 마우스 모델의 행동 특성

Angelman 증후군 마우스 모델의 행동 특성