This study has been supported by the grant NIHM R01 MH091816 and R21 MH084043 to TDG.

1. Materials and Method
1.1. The water tanks
The cylindrical tanks (30 cm height x 20 cm diameters) required for the mouse forced swim test (FST) in our laboratory are constructed of transparent Plexiglas, as this material is able to withstand the frequent movement of the tanks and accidents better than glass. The water level is 15 cm from the bottom and should be marked on the tank to ensure that the volume of water is consistent across mice. The number of tanks should ideally be at least twice as many as the number of mice being tested at a time, so that the second water tank set can be filled while the first set is in use. The dimensions of the tanks should be selected in a way that the mice will not be able to touch the bottom of the tank, either with their feet or their tails, during the swimming test. The height of the tank should be high enough to prevent the mice from escaping from the tank. Please note that the diameter of tank and the depth of water are important parameters that can be adjusted to change the behavior of mice (for a detailed analysis of these issues see1-3). 
1.2. Thermometer
A water resistant infrared thermometer is preferable, since rapid measurement of temperature reduces the amount of time required to conduct the test. However, a glass mercury thermometer will also be sufficient for this task.
1.3. Timer
1.4. Video recording device
We use a video camera supported by a tripod. Since this test usually involves multiple animals being tested at the same time, live scoring will be very difficult and is not advisable. The video camera should record in high enough resolution to render a quality picture that will be used later for behavioral scoring. Always make sure there is sufficient recording memory in the camera before starting the test. We use a video camera that records digitally without the use of mechanical media (i.e. video cassette), allowing for digital transfer of videos. If there are excessive reflections on the tanks, which may occur in laboratory environments with overhead fluorescent illumination, you may want to use a polarizing lens filter with your camera.
1.5. Dividers
In our lab we have two sets of dividers (35 cm height x 22 cm width x 22 cm depth). These are rectangular with three walls and are used as both background and as dividers between tanks to prevent mice from seeing each other during the test and potentially altering their behaviors. One set can be black for albino and light colored animals; the other set can be light colored for dark colored animals in order to render high contrast. The experimenter should make sure that the surfaces of the dividers are not overly reflective so that they alter camera images, or render major differences between illumination levels.
1.6. White noise generator
This is needed in laboratory environments in which sudden loud noises can be heard that would potentially startle the animals. The noise generator will mask such intermittent disturbing sounds. The volume level of the white noise generator should be selected to be above other ambient and unexpected noises. In our experimental room the ambient noise level (without the white noise generator activated) is 60 dB. The total noise level with the white noise generator activated at the location where the tanks are placed is 70-72 dB. However it should be noted that these figures are provided as example only, and each laboratory should select the right noise levels according to their unique environment and circumstances.
1.7. Drying paper and heat lamp
Before returning the animals to their home cages, it is important to dry them gently using paper towels and it is helpful to use a heat lamp (be certain the exposure temperature does not exceed 32&deg;C) to prevent hypothermia.
2. Behavioral Procedures
<ol>
 <li>The overall experimental design should reflect proper counterbalancing between variables specific to your experiment. For example, in our experiments, we try to represent each group equally in every FST session (i.e., if there are four treatment groups, each will be represented in each session). Also, mice are rotated, such that mice from each treatment group are placed in a different tank in each session. </li>
 <li>Place the camera and the dividers in position. The camera should be as close as possible in order to obtain the highest possible resolution of the mice.</li>
 <li>The tanks should be filled with tap water set at the room temperature (23-25&deg;C) to the determined level, which is marked on the tank walls. If your facility does not have constant hot/cold water, you may want to prepare hot water and/or ice to quickly bring the water to the right temperature. Check the water temperature with the infrared thermometer. Alternatively, if the temperatures of hot and cold water are constant at your facility, you can draw on the tank two marks &#x2013; one for the level of hot water and a second mark for the addition of cold water &#x2013; to get close to the correct final water temperature rapidly.</li>
 <li>Start the white noise generator, if being used, before the mice are introduced to the testing room. The level of white noise should only be enough to mask external noises. Avoid a high volume and make sure the same level of white noise is being used for all animals.</li>
 <li>Bring the animals into the testing room. If the colony room where the animals reside and the testing room are adjacent or very close to each other, the ambient conditions are similar and the disturbance during the moving of the cage is minimal, then no acclimation period will be necessary. Otherwise, place the animals in the testing room for a period of acclimation (generally at least one hour). If an acclimation period is necessary, make sure the acclimated animals will not be affected by the mice being tested at the same time in the same room. Please be aware that olfactory and ultrasonic cues can be sensed by the other animals placed in the same room.</li>
 <li>Start video recording before placing the animals into the water tanks.</li>
 <li>Hold the animal by its tail, and gently and slowly place in the water. Once the mice is in the water, slowly release the tail. Typically, using this procedure will prevent the animal's head from being submerged under the water. </li>
 <li>Place the mice in the tanks in an order in which the obstruction of recording will be minimized. This order, of course, should be decided in conjunction with the counterbalancing of groups and other requirements specific to your experimental design.</li>
 <li>Once all mice are in the tanks-start the countdown on the stopwatch. The usual test length for mice is six minutes in the FST.</li>
 <li>During the test be certain you are at a reasonable distance from the animals and do not make any movements or noise that may be noticed by the animals. Mice can readily float in water, however, if either a new strain of mice or a new compound being tested without previous knowledge of their effect on swimming behavior, the experimenter should monitor the animals more closely. In contrast to rats, mice do not typically dive during the FST, however in the event of diving the mouse should be removed from the tank. If the experimenter leaves the room the mice should be monitored by video in the event that a mouse cannot maintain swimming and floating behavior and to stop the test if necessary.</li>
 <li>At the end of six minute testing period stop the recording. In our lab, we show a note in front of the camera that identifies the animals at the very end of each recording. When using this approach the individual subsequently scoring the recording will not know the identity of the animals since the identity is only shown at the very end of the recording. This prevents any identification and record keeping problems that may occur later related to the recordings. Regardless of the record keeping strategy that is being used, it should clearly identify the animals and also prevent the individual later scoring the test from having knowledge of group assignments. </li>
 <li>Remove the animals from the water by their tails in the same order that you put them in and gently dry them with a drying paper and place back into their homecage.</li>
</ol>
3. Behavior Analysis
<ol>
 <li>The mouse version of FST is typically, from start to finish, six minutes long. However, generally only the last four minutes of the test are analyzed. This is due to the fact that most mice are very active at the beginning of the FST, and the potential effects of the treatment can be obscured during the first two minutes.</li>
 <li>In our laboratory we upload the video files directly from the camera to a PC and do the analysis on the PC.</li>
 <li>During the behavioral analysis, the time that each mice spends mobile is measured. The total amount of mobility time is then subtracted from the 240 seconds of test time and is then stated as the immobility time. While it is possible to measure the immobility time directly, in our laboratory we have found it easier to detect and measure active movements rather than the lack of such movements. </li>
 <li>The most important aspect of behavioral analysis and usually the biggest source of variability between observers in the FST is the correct identification of movements that are counted as bona fide mobility. Our operational definition for mobility in the FST is any movements other than those necessary to balance the body and keep the head above the water4. Mice generally float in water readily, however they still manifest small movements to balance their bodies and keep their heads above the water. These behaviors are not an attempt to escape and should not be scored as mobility. Also, after a single bout of mobility, even though essentially immobile, mice can still drift in the water as a result of momentum. These movements also should not be scored as mobility. </li>
 <li>In our laboratory, we use an on-screen stopwatch software (Xnote Stopwatch, dnSoft Research Group) for time measurements. Two separate stopwatches are used on the screen. The first stopwatch counts down from 240 seconds and alerts the observer when the behavioral analysis period ends. The second stopwatch measures the time spent mobile. Some stopwatch software has the ability to assign keys to start and stop functions, so that on-screen stopwatches can be controlled by the keyboard. In our lab, instead of a regular keyboard, we use an input device commonly known as a 'gamepad' to control the stopwatches.</li>
 <li>When using a PC to quantify immobility, if there is more than one mouse tested and present on the screen, it is a good idea to cover the other animals (you can use another program window or physically cover the screen with paper), so that their movements will not distract the observer. </li>
 <li>If an on-screen stopwatch is used, be certain to cover all but the millisecond decimals of the stopwatch. The reason for this is to prevent bias in the observer, while still allowing the ability to determine if the watch is running or not running. Since the observer, while blind to the group assignments of the animals, will have a general idea of level of mobility in the mice, there might be some bias occurring if she is allowed to see the total amount of mobility time elapsed for that particular mouse before completion of the analysis session. By covering the stopwatch, she will only know whether the stopwatch is on or off at any point but will not know the total time elapsed and therefore cannot be effected by any bias.</li>
 <li>An inter-observer reliability test should be conducted for every new observer before beginning to collect data from test animals. In our laboratory, each new observer first watches an experienced observer scoring. After the new observer gains confidence to differentiate mobility from immobility, they then score with the experienced observer watching and pointing out any mistakes. Once this phase is successfully completed, the new observer will analyze a specific set of FST videos that we keep in our laboratory for training purposes. Only after a high level of inter-observer correlation is obtained with the experienced observer does an investigator start analyzing FST videos in actual experiments. We archive the data from these training analyses to constitute an internal standard for the laboratory for future use. We have observed differences between strains in the manner in which they express mobility (and immobility) behaviors, and mean immobility time between sexes. When a new strain, sex, or genetically modified mouse model is tested in the laboratory it is necessary to again undertake this type of reliability analysis. </li>
</ol>
4. Representative Results
There are marked differences between genetically distinct inbred and outbred mouse strains in terms of their baseline immobility and responding to a specific drug5-11. For example, we identified differential antidepressant-like responses to lithium in a panel of mouse strains (Figure 1)5. Experimental details of this experiment are published in Can et al., 20115.
<img src="/files/ftp_upload/3638/3638fig1.jpg" alt="Figure 1" /> 
Figure 1. Immobility time (in seconds) in the forced swim test, five hours after a single i.p. injection of saline, 200, 300, or 400 mg/kg in various inbred and outbred mouse strains. *:p&lt;0.05, **:p&lt;0.01, ***:p&lt;0.001 denote a significant difference compared to saline group, Dunnett's post hoc test. Data are expressed as mean &plusmn; SEM. Number of animals per group for each strain is 6-8 (Figure reproduced from5).
Not all mouse strains are suitable for the FST. Some strains, such as Black Swiss, NIH Swiss, and FVB/NJ show little or almost no immobility under control conditions, therefore representing a floor effect (Figure 1)5. The lack of baseline immobility effectively prevents detecting an anti-depressant effect of experimental manipulations. It is also possible, while very rare, that some mouse strains may behave aberrantly and dive into the tank during the test even though they can float. One such strain is DBA/1OlaHsd (unpublished observation in our laboratory). Such strains are not suitable for the FST. Because of this diving risk, however small, when testing a new strain that has not been previously tested in the FST or a mouse harboring a novel genetic manipulation, it is imperative to carefully observe the initial trials to rescue mice if they engage in potentially harmful behaviors.
In the experimental design described here, multiple animals (up to five) are tested at the same time. While the dividers we use prevent mice from seeing each other during the test, and the white noise generator suppresses audible vocalizations, our set-up does not prevent all ultrasonic or olfactory cues from being transmitted. Though unlikely given the nature of the test, these could affect the behaviors of mice. One solution to this problem would be to test the animals individually. However, this approach has its own problems. For example, commonly, the animals tested in each session come from the same homecage. This allows randomization and counterbalancing of the experimental variables. Testing mice individually would mean removing one mouse at a time from the homecage. This will cause repeated stress and disturbance of social hierarchy in the cage among the others left behind. Another issue with testing singly are the time constraints. Testing one mouse at a time will extend the experiment into many hours resulting in a situation in which mice are tested at different times of the circadian cycle. This may create confounding time of day effects. The researchers should keep these issues in mind while designing their experiments.

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Authors declare no conflicts of interest.

The FST (sometimes called Porsolt swim test) was developed first for rats and then modified for mice by Porsolt and colleagues12,13. In addition to the above-described protocol successful in our laboratory, a number of largely subtle test modifications have been published (see Hasco&euml;t and Bourin for a complete review1). It is a common test used for evaluation of the efficacy of anti-depressant drugs and the effects of various behavioral and neurobiological manipulations in basic and preclinical...

<ul>
<li>Water tanks</li>
<li>Thermometer</li>
<li>Timer</li>
<li>Video Camera</li>
<li>White Noise Generator (optional)</li>
<li>Drying Paper</li>
</ul>

the mouse forced swim test

The forced swim test is a rodent behavioral test used for evaluation of antidepressant drugs, antidepressant efficacy of new compounds, and experimental manipulations that are aimed at rendering or preventing depressive-like states. Mice are placed in an inescapable transparent tank that is filled with water and their escape related mobility behavior is measured. The forced swim test is straightforward to conduct reliably and it requires minimal specialized equipment. Successful implementation of the forced swim test requires adherence to certain procedural details and minimization of unwarranted stress to the mice. In the protocol description and the accompanying video, we explain how to conduct the mouse version of this test with emphasis on potential pitfalls that may be detrimental to interpretation of results and how to avoid them. Additionally, we explain how the behaviors manifested in the test are assessed.

Watch this Scientific Journal Video about The Mouse Forced Swim Test at JoVE.com

The Mouse Forced Swim Test

The forced swim test is validated as an experimental approach to assess potential antidepressant efficacy in rodents. Experimental animals are placed in a tank of water and escape-related mobility behavior is quantified. The common procedures for the mouse version of this test are described.

The forced swim test is a rodent behavioral test used for evaluation of antidepressant drugs, antidepressant efficacy of new compounds, and experimental ...

Research

JoVE Journal

Neuroscience

104.6K Aufrufe.  University of Maryland School of Medicine. Der Forced Swim Test wird als ein experimenteller Ansatz, um mögliche antidepressive Wirksamkeit in Nagetieren zu beurteilen validiert. Versuchstiere werden in einen Behälter mit Wasser und die Flucht-bezogene Mobilitätsverhalten gelegt wird quantifiziert. Das gemeinsame Verfahren für die Maus-Version dieses Tests sind beschrieben.

Serie: The Mouse Forced Swim Test

Multiple-mouse Neuroanatomical Magnetic Resonance Imaging

The field of mouse phenotyping with magnetic resonance imaging (MRI) is rapidly growing, motivated by the need for improved tools for characterizing and evaluating mouse models of human disease. MRI is an excellent modality for investigating genetically altered animals. It is capable of whole brain coverage, can be used in vivo, and provides multiple contrast mechanisms for investigating different aspects of neuranatomy and physiology. The advent of high-field scanners along with the ability to scan multiple mice simultaneously allows for rapid phenotyping of novel mutations.
Effective mouse MRI studies require attention to many aspects of experiment design. In this article, we will describe general methods to acquire quality images for mouse phenotyping using a system that images mice concurrently in shielded transmit/receive radio frequency (RF) coils in a common magnet (Bock et al., 2003). We focus particularly on anatomical phenotyping, an important and accessible application that has shown a high potential for impact in many mouse models at our imaging centre. Before we can provide the detailed steps to acquire such images, there are important practical considerations for both in vivo brain imaging (Dazai et al., 2004) and ex vivo brain imaging (Spring et al., 2007) that should be noted. These are discussed below.

Magnetic resonance imaging (MRI) has become an increasingly popular tool for examining the phenotype of genetically altered mice. This article illustrates the methods necessary to achieve high-throughput phenotyping of genetically altered mice using multiple-mouse MRI.

The field of mouse phenotyping with magnetic resonance imaging (MRI) is rapidly growing, motivated by the need for improved tools for characterizing and ...

Detection of Neuritic Plaques in Alzheimer's Disease Mouse Model

Alzheimer's disease (AD) is the most common neurodegenerative disorder leading to dementia. Neuritic plaque formation is one of the pathological hallmarks of Alzheimer's disease. The central component of neuritic plaques is a small filamentous protein called amyloid &beta; protein (A&beta;)1, which is derived from sequential proteolytic cleavage of the beta-amyloid precursor protein (APP) by &beta;-secretase and &gamma;-secretase. The amyloid hypothesis entails that A&gamma;-containing plaques as the underlying toxic mechanism in AD pathology2. The postmortem analysis of the presence of neuritic plaque confirms the diagnosis of AD. To further our understanding of A&gamma; neurobiology in AD pathogenesis, various mouse strains expressing AD-related mutations in the human APP genes were generated. Depending on the severity of the disease, these mice will develop neuritic plaques at different ages. These mice serve as invaluable tools for studying the pathogenesis and drug development that could affect the APP processing pathway and neuritic plaque formation. In this protocol, we employ an immunohistochemical method for specific detection of neuritic plaques in AD model mice. We will specifically discuss the preparation from extracting the half brain, paraformaldehyde fixation, cryosectioning, and two methods to detect neurotic plaques in AD transgenic mice: immunohistochemical detection using the ABC and DAB method and fluorescent detection using thiofalvin S staining method.

Detection of Neuritic Plaques in Alzheimer&#039;s Disease Mouse Model

One of the pathological characteristics of AD is the formation of Amyloid &#x03B2; protein positive neuritic plaques. In this protocol we describe two methods to detect neuritic plaques in transgenic AD model mice: immunohistochemical detection using the ABC and DAB method and fluorescent detection using thioflavin S staining method.

Alzheimer's disease (AD) is the most common neurodegenerative disorder leading to dementia. Neuritic plaque formation is one of the pathological hallmarks ...

T-maze Forced Alternation and Left-right Discrimination Tasks for Assessing Working and Reference Memory in Mice

Forced alternation and left-right discrimination tasks using the T-maze have been widely used to assess working and reference memory, respectively, in rodents. In our laboratory, we evaluated the two types of memory in more than 30 strains of genetically engineered mice using the automated version of this apparatus. Here, we present the modified T-maze apparatus operated by a computer with a video-tracking system and our protocols in a movie format. The T-maze apparatus consists of runways partitioned off by sliding doors that can automatically open downward, each with a start box, a T-shaped alley, two boxes with automatic pellet dispensers at one side of the box, and two L-shaped alleys. Each L-shaped alley is connected to the start box so that mice can return to the start box, which excludes the effects of experimenter handling on mouse behavior. This apparatus also has an advantage that in vivo microdialysis, in vivo electrophysiology, and optogenetics techniques can be performed during T-maze performance because the doors are designed to go down into the floor. In this movie article, we describe T-maze tasks using the automated apparatus and the T-maze performance of &alpha;-CaMKII+/- mice, which are reported to show working memory deficits in the eight-arm radial maze task. Our data indicated that &alpha;-CaMKII+/- mice showed a working memory deficit, but no impairment of reference memory, and are consistent with previous findings using the eight-arm radial maze task, which supports the validity of our protocol. In addition, our data indicate that mutants tended to exhibit reversal learning deficits, suggesting that &alpha;-CaMKII deficiency causes reduced behavioral flexibility. Thus, the T-maze test using the modified automatic apparatus is useful for assessing working and reference memory and behavioral flexibility in mice.

This article presents the protocol of T-maze tests using a modified automated apparatus for assessing the learning and memory functions in mice.

Forced alternation and left-right discrimination tasks using the T-maze have been widely used to assess working and reference memory, respectively, in ...

The Tail Suspension Test

The tail-suspension test is a mouse behavioral test useful in the screening of potential antidepressant drugs, and assessing of other manipulations that are expected to affect depression related behaviors. Mice are suspended by their tails with tape, in such a position that it cannot escape or hold on to nearby surfaces. During this test, typically six minutes in duration, the resulting escape oriented behaviors are quantified. The tail-suspension test is a valuable tool in drug discovery for high-throughput screening of prospective antidepressant compounds. Here, we describe the details required for implementation of this test with additional emphasis on potential problems that may occur and how to avoid them. We also offer a solution to the tail climbing behavior, a common problem that renders this test useless in some mouse strains, such as the widely used C57BL/6. Specifically, we prevent tail climbing behaviors by passing mouse tails through a small plastic cylinder prior to suspension. Finally, we detail how to manually score the behaviors that are manifested in this test.

The tail-suspension test is validated as an experimental procedure to assess antidepressant efficacy of drug treatments in mice. Mice are suspended by their tails for six minutes and escape-related behaviors are assessed. We describe procedures used in conducting the tail suspension test.

The tail-suspension test is a mouse behavioral test useful in the screening of potential antidepressant drugs, and assessing of other manipulations that ...

Stereotaxic Infusion of Oligomeric Amyloid-beta into the Mouse Hippocampus

Alzheimer&#8217;s disease is a neurodegenerative disease affecting the aging population. A key neuropathological feature of the disease is the over-production of amyloid-beta and the deposition of amyloid-beta plaques in brain regions of the afflicted individuals. Throughout the years scientists have generated numerous Alzheimer&#8217;s disease mouse models that attempt to replicate the amyloid-beta pathology. Unfortunately, the mouse models only selectively mimic the disease features. Neuronal death, a prominent effect in the brains of Alzheimer&#8217;s disease patients, is noticeably lacking in these mice. Hence, we and others have employed a method of directly infusing soluble oligomeric species of amyloid-beta - forms of amyloid-beta that have been proven to be most toxic to neurons - stereotaxically into the brain. In this report we utilize male C57BL/6J mice to document this surgical technique of increasing amyloid-beta levels in a select brain region. The infusion target is the dentate gyrus of the hippocampus because this brain structure, along with the basal forebrain that is connected by the cholinergic circuit, represents one of the areas of degeneration in the disease. The results of elevating amyloid-beta in the dentate gyrus via stereotaxic infusion reveal increases in neuron loss in the dentate gyrus within 1 week, while there is a concomitant increase in cell death and cholinergic neuron loss in the vertical limb of the diagonal band of Broca of the basal forebrain. These effects are observed up to 2 weeks. Our data suggests that the current amyloid-beta infusion model provides an alternative mouse model to address region specific neuron death in a short-term basis. The advantage of this model is that amyloid-beta can be elevated in a spatial and temporal manner.

Here, we present a protocol for direct stereotaxic brain infusion of amyloid-beta. This methodology provides an alternative in vivo mouse model to address the short-term effects of amyloid-beta on brain neurons.

Alzheimer&#8217;s disease is a neurodegenerative disease affecting the aging population. A key neuropathological feature of the disease is the ...

The Fibular Nerve Injury Method: A Reliable Assay to Identify and Test Factors That Repair Neuromuscular Junctions

The neuromuscular junction (NMJ) undergoes deleterious structural and functional changes as a result of aging, injury and disease. Thus, it is imperative to understand the cellular and molecular changes involved in maintaining and repairing NMJs. For this purpose, we have developed a method to reliably and consistently examine regenerating NMJs in mice. This nerve injury method involves crushing the common fibular nerve as it passes over the lateral head of the gastrocnemius muscle tendon near the knee. Using 70 day old female mice, we demonstrate that motor axons begin to reinnervate previous postsynaptic targets within 7 days post-crush. They completely reoccupy their previous synaptic areas by 12 days. To determine the reliability of this injury method, we compared reinnervation rates between individual 70 day old female mice. We found that the number of reinnervated postsynaptic sites was similar between mice at 7, 9, and 12 days post-crush. To determine if this injury assay can also be used to compare molecular changes in muscles, we examined levels of the gamma-subunit of the muscle nicotinic receptor (gamma-AChR) and the muscle-specific kinase (MuSK). The gamma-AChR subunit and MuSK to are highly upregulated following denervation and return to normal levels following reinnervation of NMJs. We found a close relationship between transcript levels for these genes and innervation status of muscles. We believe that this method will accelerate our understanding of the cellular and molecular changes involved in repairing the NMJ and other synapses.

We have developed a nerve injury method to reliably examine muscle reinnervation, and thus regeneration of neuromuscular junctions in mice. This technique involves injuring the common fibular nerve via a simple and highly reproducible surgery. Muscle reinnervation in then assessed by whole-mounting the extensor digitorum longus muscle.

The neuromuscular junction (NMJ) undergoes deleterious structural and functional changes as a result of aging, injury and disease. Thus, it is imperative ...

Automated Analysis of C. elegans Swim Behavior Using CeleST Software

Dissecting the neuronal and neuromuscular circuits that regulate behavior remains a major challenge in biology. The nematode Caenorhabditis elegans has proven to be an invaluable model organism in helping to tackle this challenge, from inspiring technological approaches,&#160;building the human brain connectome, to actually shedding light on the specific molecular drivers of basic functional patterns. The bulk of the behavioral studies in C. elegans have been performed on solid substrates. In liquid, animals exhibit behavioral patterns that include movement at a range of speeds in 3D, as well as partial body movements, such as a posterior curl without anterior shape change, which introduce new challenges for quantitation. The steps of a simple procedure, and use of a software that enables high-resolution analysis of C. elegans swim behavior, are presented here. The software, named CeleST, uses a specialized computer program that tracks multiple animals simultaneously and provides novel measures of C. elegans locomotion in liquid (swimming). The measures are mostly grounded in animal posture and based on mathematics used in computer vision and pattern recognition, without computational requirements for threshold cut-offs. The software tool can be used to both assess overall swimming prowess in hundreds of animals from combined small batch trials and to reveal novel phenotypes even in well-characterized genetic mutants. The preparation of specimens for analysis with CeleST is simple and low-tech, enabling wide adaptation by the scientific community. Use of the computational approach described here should therefore contribute to the greater understanding of behavior and behavioral circuits in the C. elegans model.

Automated Analysis of C. elegans Swim Behavior Using CeleST Software

An efficient and simple methodology for computer-based analysis of nematode swimming behavior in liquid is described. The method requires little to no investment for C. elegans laboratories. The hardware used is standard, and the computer software for the behavioral analysis (CeleST) is an open source one.

Dissecting the neuronal and neuromuscular circuits that regulate behavior remains a major challenge in biology. The nematode Caenorhabditis elegans has ...

Diffuse Reflectance Spectroscopy: Getting the Capillary Refill Test Under One's Thumb

The capillary refill test was introduced in 1947 to help estimate circulatory status in critically ill patients. Guidelines commonly state that refill should occur within 2 s after releasing 5 s of firm pressure (e.g., by the physician&#39;s finger) in the normal healthy supine patient. A slower refill time indicates poor skin perfusion, which can be caused by conditions including sepsis, blood loss, hypoperfusion, and hypothermia. Since its introduction, the clinical usefulness of the test has been debated. Advocates point out its feasibility and simplicity and claim that it can indicate changes in vascular status earlier than changes in vital signs such as heart rate. Critics, on the other hand, stress that the lack of standardization in how the test is performed and the highly subjective nature of the naked eye assessment, as well as the test&#39;s susceptibility to ambient factors, markedly lowers the clinical value. The aim of the present work is to describe in detail the course of the refill event and to suggest potentially more objective and exact endpoint values for the capillary refill test using diffuse polarization spectroscopy.

Diffuse Reflectance Spectroscopy: Getting the Capillary Refill Test Under One&#039;s Thumb

This protocol describes how the use of diffuse polarization spectroscopy can improve the clinical usefulness of the capillary refill test. We suggest a more detailed analysis of the course of the capillary refill in healthy volunteers using diffuse reflectance spectroscopy videos and new informatic endpoints.

The capillary refill test was introduced in 1947 to help estimate circulatory status in critically ill patients. Guidelines commonly state that refill ...

A Metric Test for Assessing Spatial Working Memory in Adult Rats Following Traumatic Brain Injury

Impairments to sensory, short-term, and long-term memory are common side effects after traumatic brain injury (TBI). Due to the ethical limitations of human studies, animal models provide suitable alternatives to test treatment methods, and to study the mechanisms and related complications of the condition. Experimental rodent models have historically been the most widely used due to their accessibility, low cost, reproducibility, and validated approaches. A metric test, which tests the ability to recall the placement of two objects at various distances and angles from one another, is a technique to study impairment in spatial working memory (SWM) after TBI. The significant advantages of metric tasks include the possibility of dynamic observation, low cost, reproducibility, relative ease of implementation, and low stress environment. Here, we present a metric test protocol to measure impairment of SWM in adult rats after TBI. This test provides a feasible way to evaluate physiology and pathophysiology of brain function more effectively.

Traumatic brain injury (TBI) is commonly associated with memory impairment. Here, we present a protocol to assess spatial working memory after TBI via a metric task. A metric test is a useful tool to study spatial working memory impairment after TBI.

Impairments to sensory, short-term, and long-term memory are common side effects after traumatic brain injury (TBI). Due to the ethical limitations of ...

Assessment of Swim Endurance and Swim Behavior in Adult Zebrafish

Due to their renowned regenerative capacity, adult zebrafish are a premier vertebrate model to interrogate mechanisms of innate spinal cord regeneration. Following complete transection of their spinal cord, zebrafish extend glial and axonal bridges across severed tissue, regenerate neurons proximal to the lesion, and regain their swim capacities within 8 weeks of injury. Recovery of swim function is thus a central readout for functional spinal cord repair. Here, we describe a set of behavioral assays to quantify zebrafish motor capacity inside an enclosed swim tunnel. The goal of these methods is to provide quantifiable measurements of swim endurance and swim behavior in adult zebrafish. For swim endurance, zebrafish are subjected to a constantly increasing water current velocity until exhaustion, and time at exhaustion is reported. For swim behavior assessment, zebrafish are subjected to low current velocities and swim videos are captured with a dorsal view of the fish. Percent activity, burst frequency, and time spent against the water current provide quantifiable readouts of swim behavior. We quantified swim endurance and swim behavior in wild-type zebrafish before injury and after spinal cord transection. We found that zebrafish lose swim function after spinal cord transection and gradually regain that capacity between 2 and 6 weeks post-injury. The methods described in this study could be applied to neurobehavioral, musculoskeletal, skeletal muscle regeneration, and neural regeneration studies in adult zebrafish.

Capable of functional recovery after spinal cord injury, adult zebrafish is a premier model system to elucidate innate mechanisms of neural regeneration. Here, we describe swim endurance and swim behavior assays as functional readouts of spinal cord regeneration.

Due to their renowned regenerative capacity, adult zebrafish are a premier vertebrate model to interrogate mechanisms of innate spinal cord regeneration. ...