This research was supported by Grants-in-Aid for Scientific Research of the Japan Society for the Promotion of Science (JSPS), Grant-in-Aid from Ministry of Education, Culture, Sports, Science and Technology in Japan, Grants-in-Aid from BIRD and CREST of Japan Science and Technology Agency, Grant-in-Aid from Neuroinformatics Japan Center (NIJC), RIKEN and by Grant-in-Aid for Scientific Research on Priority Areas-Integrative Brain Research (Shien)- from MEXT in Japan. We thank O'hara &amp; Co. and Mariko Hayashi for their assistance in creating this movie.

Protocol
<ol>
<li>The apparatus used for the elevated plus maze test is in the configuration of a + and comprises two open arms (25 x 5 x 0.5 cm) across from each other and perpendicular to two closed arms (25 x 5 x 16 cm) with a center platform (5 x 5 x 0.5 cm). The open arms have a very small (0.5 cm) wall to decrease the number of falls, whereas the closed arms have a high (16 cm) wall to enclose the arm. The entire apparatus is 50 cm above the floor (Ohara &amp; Co., Tokyo) and is placed in an empty circular tank (100 cm diameter, 35 cm tall; normally used for the Morris water maze task) to protect the mice that fall or attempt to escape during the experiment. The apparatus is made of plastic materials. The platform is white and the walls are transparent. There is a variation in materials and colors of the apparatus of elevated plus maze. </li>
<li>Mice are housed with a 12-h light/dark cycle (lights on at 7:00 AM), as previously described (Takao &amp; Miyakawa, 2006a). Behavioral testing is performed between 9:00 AM and 6:00 PM. All the experimental mice are transferred to the behavior testing room 30 min prior to beginning the first trial to habituate to the condition of the behavior testing room. The order of trials is counterbalanced across genotypes. There are two purposes of the test trial using a practice animal. One is to make sure that everything is fine with the recording system. Another is to keep the testing condition as uniform as possible. That is, the very first mouse in the entire session would experience somewhat different condition with others (i.e., no prior noises made by testing operations and no odor cues from previous trials) without such a practice trial. Animals are maintained according to the guidelines of the Animal Research Committee of Kyoto University. </li>
<li>The behavior testing room (170 x 210 x 200 cm, Ohara &amp; Co., Tokyo) is soundproof and the illumination level is maintained at 100 lux. A mouse is placed in the center area of the maze with its head directed toward a closed arm. The elevated plus maze test is recorded using a video camera attached to a computer, which is controlled by a remote device. The number of entries (an entry is defined as the center of mass of the mouse enters the arm) into each arm and the time spent in the open arms are recorded and these measurements serve as an index of anxiety-like behavior. </li>
<li>Mice are allowed to move freely about the maze for 10 min. Each mouse receives one trial in our test battery. The application used for acquiring and analyzing the behavioral data (Image EP) is based on the public domain Image J program (developed by Wayne Rasband at the National Institute of Mental Health and available at <a href="http://rsb.info.nih.gov/ij/">http://rsb.info.nih.gov/ij/</a>), which was modified by Tsuyoshi Miyakawa (available through O'Hara &amp; Co., Tokyo, Japan). </li>
<li>The distance traveled, the number of entries into each arm, the time spent in each arm, and the percent of entries into the open arms are calculated by the Image EP program. </li>
<li>After each trial, all arms and the center area are cleaned with super hypochlorous water, that is an efficient odor removal agent and has relatively weak odor of itself compared to other cleaning solutions, to prevent a bias based on olfactory cues. Thus we can conduct the tests under controlled condition regarding olfactory cues. </li>
</ol>

<ol>
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All procedures were approved by the Animal Use and Care Committee of Kyoto University.

Although the mouse genome has been sequenced, the functions of most of the genes are not known. Genetic modification techniques allow for deletion or other manipulation of a specific gene in mice (Austin et al., 2004; Aiba et al., 2007). The influence of a given gene on a specific behavior can then be determined by conducting behavioral analyses of the mutant mice (Takao and Miyakawa, 2006b; Takao et al., 2007).
The elevated plus maze test is one of the most popular tests of all currently available animal models of anxiety (Rodgers and Dalvi, 1997; Crawley, 2007). This test for anxiety-like behavior has been used for screening and phenotyping transgenic and knockout mice (Crawley, 1999) and for drug discovery (Hogg et al. 1996; Crawley, 2007). The elevated plus maze test has a strong predictive validity for screening anxiolytic drugs (Rodgers and Dalvi, 1997; Mechiel Korte and De Boer, 2003; Crawley, 2007); anxiolytic drugs specifically increase, and anxiogenic drugs specifically decrease, the number of entries into the open arms and the time spent there. The total entries score and total distance are considered a useful index of general activity. Total entries score is also an index of anxiety, and the percentages of entries and time spent in each arm constitute the index of primary anxiety (Rodgers and Dalvi, 1997, Mechiel Korte and De Boer, 2003). The open and closed arms are considered to evoke the same exploratory drive, therefore avoidance of the open arms is considered to be a result of the induction of higher levels of fear (Rodgers and Dalvi, 1997). It is thought that the aversion of mice to explore the open arms of the maze is caused by fear of open and elevated spaces.
In 1984, Handley and Mithani reported on preliminary work with the elevated X (plus) maze test described above. The original test apparatus was raised 70 cm above the floor, and comprised two closed and two open arms, each of which measured 45 cm long by 10 cm wide. In their initial studies, they reported the ratio of open/total arm entries (Handley and Mithani, 1984). Subsequently, other indices were developed that included the number of entries into the closed and open arms and the time spent in the closed and open arms for rats (Pellow et al, 1985; Pellow and File, 1986) and mice (Lister, 1987).
Changes to the elevated plus maze test included lengthening of both the open arms (50 x 10 cm) and closed arms (50 x 10 x 40 cm) with tall surrounding walls and an open roof on the closed arms, and the entire maze was elevated to a height of 50 cm (Pellow et al, 1985; Pellow and File, 1986). Presently, in our laboratory, the elevated plus maze test apparatus is configured in the shape of a +, with two open arms (25 x 5 cm, with a very slight, 0.5-cm, wall) across from each other and perpendicular to two closed arms (25 x 5 x 16 cm), and is raised 50 cm above the floor (Miyakawa et al, 1996; Manabe et al, 2000; Miyakawa et al, 2001; Seeger et al, 2004; Morishima et al, 2005; Miyamoto et al, 2005; Arrow et al, 2006; Hattori et al, 2007; Niemann et al, 2007; Sano et al, 2008; Horii et al, 2008; Fukuda et al, 2008; Ikeda et al; 2008). The mouse is placed in the center of the + (5 cm x 5 cm) and is allowed to explore the maze freely. Though 5 min recording is common, the behavior is recorded for 10 min in our protocol to increase the opportunity to detect the phenotype. The open and closed elevated arms induce an exploration conflict (Mechiel Korte and De Boer, 2003; Crawley, 2007).
The measures of the elevated plus maze test are recorded by an observer during the experiment. In our laboratory, the test is recorded with a video camera connected to a computer and the behavioral data (Image EP) are acquired and analyzed using the Image EP program. Number of entries onto the open arms versus number of total arm entries, and time spent on the open arms versus closed arms, provide the measures of anxiety-like behavior.
We assessed more than 90 strains of genetically engineered mutant mice using the protocol shown in the movie and have a large set of raw data for more than 5000 mice (including wild-type and mutant mice). In our test battery, wild-type littermates are usually used as a control. As a background strain, C57BL/6J mice are widely used. We collected the data of C57BL/6J mice in the behavioral tests. The values obtained from C57BL/6J mice in our elevated plus maze test are as follows (n=914; mean SEM); total distance traveled: 1547.55 14.27 cm; duration of time spent: 56.49 2.42 s (open arms), 384.02 3.13 s (closed arms), 161.90 2.17 s (maze center); ratio of time spent in the open arms: 9.19 0.36%, ratio of time spent in the closed arms: 63.82 0.52%; number of entries: 7.64 0.21 (open arms), 24.32 0.28 (closed arms); % open arm entries: 21.9 0.05, % closed arms entries: 78.1 0.05. C57BL/6J mice spend less time in open arms than in closed arms (p&lt;0.0001, n=914, paired-t test). This indicates that C57BL/6J mice tend to avoid the open arms, and that the time spent in the open arms is a valid index of anxiety-like behavior. Additionally, the order of trials is counterbalanced across genotypes, because the trial number affects the time spent in the open arms and the center platform. That is, the indices all increase during the 3rd and 4th mice compared to the 1st mice (p=0.0089, n=476) (unpublished data). With our protocol, analysis of more than 1661 mice showed that the sequential order of the mice tested in a cage does not significantly affect the open arm stay time (unpublished data). That is, the performances of the first mice taken from the cage do not significantly differ from those of the second, the third or the last mice.
Although the elevated plus maze test and the light/dark transition test are both used for assessing anxiety-like behavior, the results are not always consistent between them (Holmes et al, 2000; Tujimura et al, 2008; Nakajima et al, in press) For example, forebrain-specific calcineurin-knockout mice spend a decreased amount of time in the light chamber in the light/dark transition test, but an increased amount of time in the open arms in the elevated plus maze test (Miyakawa et al., 2003). Factor analysis of our behavioral test battery indicates that the elevated plus maze test and the light/dark transition test assess different aspects of anxiety-like behavior, such as bright-space anxiety in the light/dark transition test and open-space anxiety-like behavior in the open field test (Takao and Miyakawa, 2006b; Yamasaki et al, 2006). Accordingly, both the light/dark transition test and the elevated plus maze test are included in our behavioral test battery.
Crabbe and colleagues reported that uncontrolled variables and experiments characterizing mutants may yield results that are specific to a particular laboratory (Crabbe et al., 1999). The procedural differences that exist between laboratories make it difficult to replicate or compare the results among them. Establishing visual documentation of the protocol will promote better understanding of experimental procedures, allowing for standardization of the protocols used across laboratories and for comparisons of the behavioral phenotypes of various strains of mutant mice assessed using these tests. We previously published a movie protocol of the light/dark transition test (Takao and Miyakawa, 2006a). Likewise, movies of other protocols, such as for the open field test, the porsolt forced swim test, and fear conditioning tests that we use in our behavioral test battery are presently being made for publication as future video journal articles.

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elevated plus maze for mice

Although the mouse genome is now completely sequenced, the functions of most of the genes expressed in the brain are not known. The influence of a given gene on a specific behavior can be determined by behavioral analysis of mutant mice. If a target gene is expressed in the brain, behavioral phenotype of the mutant mice could elucidate the genetic mechanism of normal behaviors. The elevated plus maze test is one of the most widely used tests for measuring anxiety-like behavior. The test is based on the natural aversion of mice for open and elevated areas, as well as on their natural spontaneous exploratory behavior in novel environments. The apparatus consists of open arms and closed arms, crossed in the middle perpendicularly to each other, and a center area. Mice are given access to all of the arms and are allowed to move freely between them. The number of entries into the open arms and the time spent in the open arms are used as indices of open space-induced anxiety in mice. Unfortunately, the procedural differences that exist between laboratories make it difficult to duplicate and compare results among laboratories. Here, we present a detailed movie demonstrating our protocol for the elevated plus maze test. In our laboratory, we have assessed more than 90 strains of mutant mice using the protocol shown in the movie. These data will be disclosed as a part of a public database that we are now constructing.
Visualization of the protocol will promote better understanding of the details of the entire experimental procedure, allowing for standardization of the protocols used in different laboratories and comparisons of the behavioral phenotypes of various strains of mutant mice assessed using this test. 


Watch this Scientific Journal Video about Elevated Plus Maze for Mice at JoVE.com

Elevated Plus Maze for Mice

The elevated plus maze test is one of the most widely used tests for measuring anxiety-like behavior in mice. Here, we present a movie showing the detailed procedures for conducting the test.

Although the mouse genome is now completely sequenced, the functions of most of the genes expressed in the brain are not known. The influence of a given ...

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89.7K Views.  Graduate School of Medicine, Kyoto University. The elevated plus maze test is one of the most widely used tests for measuring anxiety-like behavior in mice. Here, we present a movie showing the detailed procedures for conducting the test.

Video: Elevated Plus Maze for Mice

Light/dark Transition Test for Mice

Although all of the mouse genome sequences have been determined, we do not yet know the functions of most of these genes. Gene-targeting techniques, however, can be used to delete or manipulate a specific gene in mice. The influence of a given gene on a specific behavior can then be determined by conducting behavioral analyses of the mutant mice. As a test for behavioral phenotyping of mutant mice, the light/dark transition test is one of the most widely used tests to measure anxiety-like behavior in mice. The test is based on the natural aversion of mice to brightly illuminated areas and on their spontaneous exploratory behavior in novel environments. The test is sensitive to anxiolytic drug treatment. The apparatus consists of a dark chamber and a brightly illuminated chamber. Mice are allowed to move freely between the two chambers. The number of entries into the bright chamber and the duration of time spent there are indices of bright-space anxiety in mice. To obtain phenotyping results of a strain of mutant mice that can be readily reproduced and compared with those of other mutants, the behavioral test methods should be as identical as possible between laboratories. The procedural differences that exist between laboratories, however, make it difficult to replicate or compare the results among laboratories. Here, we present our protocol for the light/dark transition test as a movie so that the details of the protocol can be demonstrated. In our laboratory, we have assessed more than 60 strains of mutant mice using the protocol shown in the movie. Those data will be disclosed as a part of a public database that we are now constructing.

Visualization of the protocol will facilitate understanding of the details of the entire experimental procedure, allowing for standardization of the protocols used across laboratories and comparisons of the behavioral phenotypes of various strains of mutant mice assessed using this test.

The light/dark transition test is one of the most widely used tests to measure anxiety-like behavior in mice. Here, we present a movie that shows detailed procedures on how we conduct the test.

Światło / ciemność test przejścia dla Myszy

Although all of the mouse genome sequences have been determined, we do not yet know the functions of most of these genes. Gene-targeting techniques, ...

Morris Water Maze Experiment

The Morris water maze is widely used to study spatial memory and learning. Animals are placed in a pool of water that is colored opaque with powdered non-fat milk or non-toxic tempera paint, where they must swim to a hidden escape platform. Because they are in opaque water, the animals cannot see the platform, and cannot rely on scent to find the escape route. Instead, they must rely on external/extra-maze cues. As the animals become more familiar with the task, they are able to find the platform more quickly. Developed by Richard G. Morris in 1984, this paradigm has become one of the "gold standards" of behavioral neuroscience.

The Morris water maze is a well-accepted tool used to document the involvement of the hippocampus in a behavioral task.

The Morris water maze is widely used to study spatial memory and learning. Animals are placed in a pool of water that is colored opaque with powdered ...

Polymerase Chain Reaction: Basic Protocol Plus Troubleshooting and Optimization Strategies

In the biological sciences there have been technological advances that catapult the discipline into golden ages of discovery. For example, the field of microbiology was transformed with the advent of Anton van Leeuwenhoek&#39;s microscope, which allowed scientists to visualize prokaryotes for the first time. The development of the polymerase chain reaction (PCR) is one of those innovations that changed the course of molecular science with its impact spanning countless subdisciplines in biology. The theoretical process was outlined by Keppe and coworkers in 1971; however, it was another 14 years until the complete PCR procedure was described and experimentally applied by Kary Mullis while at Cetus Corporation in 1985. Automation and refinement of this technique progressed with the introduction of a thermal stable DNA polymerase from the bacterium Thermus aquaticus, consequently the name Taq DNA polymerase.
PCR is a powerful amplification technique that can generate an ample supply of a specific segment of DNA (i.e., an amplicon) from only a small amount of starting material (i.e., DNA template or target sequence). While straightforward and generally trouble-free, there are pitfalls that complicate the reaction producing spurious results. When PCR fails it can lead to many non-specific DNA products of varying sizes that appear as a ladder or smear of bands on agarose gels. Sometimes no products form at all. Another potential problem occurs when mutations are unintentionally introduced in the amplicons, resulting in a heterogeneous population of PCR products. PCR failures can become frustrating unless patience and careful troubleshooting are employed to sort out and solve the problem(s). This protocol outlines the basic principles of PCR, provides a methodology that will result in amplification of most target sequences, and presents strategies for optimizing a reaction. By following this PCR guide, students should be able to: 
 
&#9679; Set up reactions and thermal cycling conditions for a conventional PCR experiment 
&#9679; Understand the function of various reaction components and their overall effect on a PCR experiment 
&#9679; Design and optimize a PCR experiment for any DNA template 
&#9679; Troubleshoot failed PCR experiments

PCR has emerged as a common technique in many molecular biology laboratories. Provided here is a quick guide to several conventional PCR protocols. Because each reaction is a unique experiment, optimal conditions required to generate a product vary. Understanding the variables in a reaction will greatly enhance troubleshooting efficiency, thereby increasing the chance to obtain the desired result.

In the biological sciences there have been technological advances that catapult the discipline into golden ages of discovery. For example, the field of ...

Milk Collection Methods for Mice and Reeves' Muntjac Deer

Animal models are commonly used throughout research laboratories to accomplish what would normally be considered impractical in a pathogen&#8217;s native host. Milk collection from animals allows scientists the opportunity to study many aspects of reproduction including vertical transmission, passive immunity, mammary gland biology, and lactation. Obtaining adequate volumes of milk for these studies is a challenging task, especially from small animal models. Here we illustrate an inexpensive and facile method for milk collection in mice and Reeves&#8217; muntjac deer that does not require specialized equipment or extensive training. This particular method requires two researchers: one to express the milk and to stabilize the animal, and one to collect the milk in an appropriate container from either a Muntjac or mouse model. The mouse model also requires the use of a P-200 pipetman and corresponding pipette tips. While this method is low cost and relatively easy to perform, researchers should be advised that anesthetizing the animal is required for optimal milk collection.

Milk Collection Methods for Mice and Reeves&#039; Muntjac Deer

Milk collection from animal models facilitates various research avenues: understanding passive immunity, identifying pathogens responsible for vertical transmission and, through the use of transgenic mice, even commercial production of proteins found in human breast milk. Here we illustrate a simple method for milk collection in mice and Reeves&#8217; muntjac deer.

Animal models are commonly used throughout research laboratories to accomplish what would normally be considered impractical in a pathogen&#8217;s native ...

Intravenous Injections in Neonatal Mice

Intravenous injection is a clinically applicable manner to deliver therapeutics. For adult rodents and larger animals, intravenous injections are technically feasible and routine. However, some mouse models can have early onset of disease with a rapid progression that makes administration of potential therapies difficult. The temporal (or facial) vein is just anterior to the ear bud in mice and is clearly visible for the first two days after birth on either side of the head using a dissecting microscope. During this window, the temporal vein can be injected with volumes up to 50 &#956;l. The injection is safe and well tolerated by both the pups and the dams. A typical injection procedure is completed within 1-2 min, after which the pup is returned to the home cage. By the third postnatal day the vein is difficult to visualize and the injection procedure becomes technically unreliable. This technique has been used for delivery of adeno-associated virus (AAV) vectors, which in turn can provide almost body-wide, stable transgene expression for the life of the animal depending on the viral serotype chosen.

Animal models of pediatric disease can experience early onset and aggressive disease progression. Clinically relevant therapy delivery to young mouse models can be technically difficult. This protocol describes a non-invasive intravenous injection method for newborn mice within the first two postnatal days of life.

Intravenous injection is a clinically applicable manner to deliver therapeutics. For adult rodents and larger animals, intravenous injections are ...

Subcloning Plus Insertion (SPI) - A Novel Recombineering Method for the Rapid Construction of Gene Targeting Vectors

Gene targeting refers to the precise modification of a genetic locus using homologous recombination. The generation of novel cell lines and transgenic mouse models using this method necessitates the construction of a &#8216;targeting&#8217; vector, which contains homologous DNA sequences to the target gene, and has for many years been a limiting step in the process. Vector construction can be performed in vivo in Escherichia coli cells using homologous recombination mediated by phage recombinases using a technique termed recombineering. Recombineering is the preferred technique to subclone the long homology sequences (>4kb) and various targeting elements including selection markers that are required to mediate efficient allelic exchange between a targeting vector and its cognate genomic locus. Typical recombineering protocols follow an iterative scheme of step-wise integration of the targeting elements and require intermediate purification and transformation steps. Here, we present a novel recombineering methodology of vector assembly using a multiplex approach. Plasmid gap repair is performed by the simultaneous capture of genomic sequence from mouse Bacterial Artificial Chromosome libraries and the insertion of dual bacterial and mammalian selection markers. This subcloning plus insertion method is highly efficient and yields a majority of correct recombinants. We present data for the construction of different types of conditional gene knockout, or knock-in, vectors and BAC reporter vectors that have been constructed using this method. SPI vector construction greatly extends the repertoire of the recombineering toolbox and provides a simple, rapid and cost-effective method of constructing these highly complex vectors.

Subcloning Plus Insertion SPI - A Novel Recombineering Method for the Rapid Construction of Gene Targeting Vectors

Gene targeting methodologies can be used to generate transgenic mice with knockout, knock-in and tagged alleles. Here, we describe an improved method of recombineering in E. coli, that we term &#8216;subcloning plus insertion&#8217;, which can be used to generate custom gene targeting vectors rapidly.

Gene targeting refers to the precise modification of a genetic locus using homologous recombination. The generation of novel cell lines and transgenic ...

A Strategy to Validate the Role of Callose-mediated Plasmodesmal Gating in the Tropic Response

The plant hormone auxin plays an important role in many growth and developmental processes, including tropic responses to light and gravity. The establishment of an auxin gradient is a key event leading to phototropism and gravitropism. Previously, polar auxin transport (PAT) was shown to establish an auxin gradient in different cellular domains of plants. However, Han et al. recently demonstrated that for proper auxin gradient formation, plasmodesmal callose-mediated symplasmic connectivity between the adjacent cells is also a critical factor. In this manuscript, the strategy to elucidate the role of particular genes, which can affect phototropism and gravitropism by altering the symplasmic connectivity through modulating plasmodesmal callose synthesis, is discussed. The first step is to screen aberrant tropic responses from 3-day-old etiolated seedlings of mutants or over-expression lines of a gene along with the wild type. This preliminary screening can lead to the identification of a range of genes functioning in PAT or controlling symplasmic connectivity. The second screening involves the sorting of candidates that show altered tropic responses by affecting symplasmic connectivity. To address such candidates, the movement of a symplasmic tracer and the deposition of plasmodesmal callose were examined. This strategy would be useful to explore new candidate genes that can regulate symplasmic connectivity directly or indirectly during tropic responses and other developmental processes.

This article describes the methods for screening the genes controlling plasmodesmal permeability and hence auxin gradient during tropic response. This includes the measurement of the degree of tropic response in hypocotyl of Arabidopsis thaliana and checking plasmodesmal permeability by 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) loading and finally callose level assessment.

The plant hormone auxin plays an important role in many growth and developmental processes, including tropic responses to light and gravity. The ...

An Antegrade Perfusion Method for Cardiomyocyte Isolation from Mice

In basic research using mouse heart, isolating viable individual cardiomyocytes is a crucial technical step to overcome. Traditionally, isolating cardiomyocytes from rabbits, guinea pigs or rats has been performed via retrograde perfusion of the heart with enzymes using a Langendorff apparatus. However, a high degree of skill is required when this method is used with a small mouse heart. An antegrade perfusion method that does not use a Langendorff apparatus was recently reported for the isolation of mouse cardiomyocytes. We herein report a complete protocol for the improved antegrade perfusion of the excised heart to isolate individual heart cells from adult mice (8 - 108 weeks old). Antegrade perfusion is performed by injecting perfusate near the apex of the left ventricle of the excised heart, the aorta of which was clamped, using an infusion pump. All procedures are carried out on a pre-warmed heater mat under a microscope, which allows for the injection and perfusion processes to be monitored. The results suggest that ventricular and atrial myocytes, and fibroblasts can be well isolated from a single adult mouse simultaneously.

We developed a simple method for isolating high quality individual mouse heart cells by the antegrade perfusion technique. This method is Langendorff-free and useful for isolating ventricular and atrial myocytes or interstitial cells, such as cardiac fibroblasts or progenitors.

In basic research using mouse heart, isolating viable individual cardiomyocytes is a crucial technical step to overcome. Traditionally, isolating ...

Terminal H-reflex Measurements in Mice

The Hoffmann reflex (H-reflex), as an electrical analog to the stretch reflex, allows electrophysiological validation of the integrity of neural circuits after injuries such as spinal cord damage or stroke. An increase of the H-reflex response, together with symptoms like non-voluntary muscle contractions, pathologically augmented stretch reflex, and hypertonia in the corresponding muscle, is an indicator of post-stroke spasticity (PSS).
In contrast to rather nerve-unspecific transcutaneous measurements, here, we present a protocol to quantify the H-reflex directly at the ulnar and median nerves of the forepaw, which is applicable, with minor modifications, to the tibial and sciatic nerve of the hindpaw. Based on the direct stimulation and the adaptation to different nerves, the method represents a reliable and versatile tool to validate electrophysiological changes in spasticity-related disease models.

The clinical evaluation of spasticity based on the Hoffmann reflex (H-reflex) and using electrical stimulation of peripheral nerves is an established method. Here, we provide a protocol for a terminal and direct nerve stimulation for H-reflex quantification in the mouse forepaw.

The Hoffmann reflex (H-reflex), as an electrical analog to the stretch reflex, allows electrophysiological validation of the integrity of neural circuits ...

A Modified Technique for Transverse Aortic Constriction in Mice

Transverse aortic constriction (TAC) is a frequently used surgery in research regarding heart failure and cardiac hypertrophy based on the formation of pressure overload in mouse models. The main challenge of this procedure is to clearly visualize the transverse aortic arch and precisely band the target vessel. Classical approaches perform a partial thoracotomy to expose the transverse aortic arch. However, it is an open-chest model that causes a rather large surgical trauma and requires a ventilator during the surgery. To prevent unnecessary trauma and simplify the operating procedure, the aortic arch is approached via the proximal proportion of the sternum, reaching and binding the target vessel using a small self-made retractor that contains a snare. This procedure can be conducted without entering the pleura cavity and does not need a ventilator or microsurgical operation, which leaves the mice with physiological breathing patterns, simplifies the procedure, and significantly reduces operation time. Due to the less invasive approach and less operation time, mice can undergo fewer stress reactions and recover rapidly.

The present protocol describes a modified and simplified technique with a minimally invasive transverse aortic constriction (TAC) procedure using a self-made retractor. This procedure can be conducted without a ventilator or microscope and introduces pressure overload, eventually leading to cardiac hypertrophy or heart failure.

Transverse aortic constriction (TAC) is a frequently used surgery in research regarding heart failure and cardiac hypertrophy based on the formation of ...