In practice, Space Station users will be asked to agree to an interparty waiver of liability as part of their contract with the European Space Agency, stating that each party will not bring claims in arbitration or sue the other party as a result of International Space Station activities. In theory, the ANSI-C99 parser should be a superset of the former C import, but we decided to keep the old, now deprecated, C parser temporarily in the product - just in case.
A cached Structorizer WebStart most likely won't work anymore redirection will fail - so you will have to launch the WebStart from this homepage again. With a previously downloaded local Structorizer installation the version check won't work anymore, i.
The new version is prepared to work with the new URLs for version check, user guide etc. Moreover it incorporates some bugfixes and improvements as described in the Changelog. In addition, the WebStart version now correctly establishes the file associations for all three Structorizer file types.
This means that e. Other models of rat elevated plus mazes have been constructed out of other materials i. We do not find this to be the case with this maze built to our specifications and the data collected are comparable. Our maze is made of stainless steel, which is painted matte black, and consists of four arms two open without walls and two enclosed by Each arm of the maze is attached to sturdy metal legs such that it is elevated 40 cm off of the table it is on.
The maze was purchased from Columbus Instruments. In comparison to the rat elevated plus maze that we use, the mouse maze is smaller and is readily moved as necessary. As such, a mouse elevated plus maze constructed of stainless steel without a movable base is used in our laboratory.
We have found similar patterns of behavior when we have used mouse elevated plus mazes from other commercial vendors and with slightly different construction i. In our laboratory, a video-tracking system e. We use the program installed on a Dell PC computer with a digital video camera mounted overhead on the ceiling. Our rat and mouse elevated plus mazes are situated in separate brightly lit rooms that are illuminated with six, W fluorescent overhead lights each, which produce consistent illumination within the rooms 2, lumens each.
The rat elevated plus maze is placed close to the center of the room, and has similar levels of illumination on both open and closed arms.
The mouse elevated plus maze is placed on a table but could also be placed on the floor such that there are similar levels of illumination on both open and closed arms.
The legs of the maze are adjusted so that the maze is perpendicular to the ground and each arm is level. Level of light can influence behavior in the elevated plus maze. As such, lighting needs to be considered when experiments using the elevated plus maze are designed.
The primary method for data collection that is used in our laboratory is the use of the video-tracking system, described above, which automatically detects and records when rats or mice enter the open or closed arms of the maze and the time spent in each.
If there are problems with contrast e. Although this occurs infrequently, an observer is always present in the testing room, next to the maze, and is simultaneously collecting elevated plus maze data. The observer makes hatchmarks on a data sheet for each arm entry that a rodent makes in the elevated plus maze and uses a timer to determine the duration spent on the open arms. This allows for comparisons between the two methods of data collection.
As such, in the testing situation that is set up in our laboratory, it is important that the observer is in the testing room while animals are tested. Furthermore, it is critically important that the observer makes minimal movements and no noise when collecting behavioral data. In some of our testing rooms that are large enough, we have set up a curtain that hangs from the ceiling and separates the area where the elevated plus maze and observer are located, which minimizes the possibility of experimental animals reacting to the presence of the observer.
However, we have found little evidence of differences in behavioral data of rodents that are tested with and without an observer that is visible to the rodent if the observer makes every effort to minimize movement and noises made. Many variables can confound interpretation of behavior in the elevated plus maze, and details of how these are addressed in our own laboratory are described.
Before an experiment using the elevated plus maze is performed, it is important to first calibrate the task in a particular laboratory by taking into account and minimizing these procedural and organismic variables so that the testing environment and experience is the same in each experimental animal. Use of the elevated plus maze should also be validated in each laboratory that it is set up in.
This can be accomplished by using positive and negative control groups, that is, administering pharmacological anxiolytics or anxiogenics, respectively. As such, in our laboratory, we have used gonadectomized adult male rodents, which have their primary endogenous sources of androgens, such as testosterone and its metabolite i.
Typically, analysis of variance can be used to assess the effects of treatment on the following measures: This may be particularly helpful if there are differences between groups in the general motor activity in the maze. When this occurs, the experimenter must rapidly pick the animal up and place it back onto the open arms of the maze.
This behavior must be recorded on the data sheet and taken into consideration when the behavioral data are analyzed. Behavioral data from an animal that does this would be excluded from analyses. However, the experimenter continues to test the animal because it is important to make sure that exposure to the elevated plus maze is as consistent across animals as possible, particularly when animals are tested in a battery of tasks. If a noise or movement occurs while rodents are on the open arms of the elevated plus maze, rodents are likely to freeze for an extended period of time, even the majority of the testing time, on the open arms of the maze.
This is a rare occurrence i. If freezing were to occur, the experimenter must make a note of this on their data sheets and consider this anomaly when analyzing the behavioral results.
However, the experimenter continues to test the animal so that it is exposed to the elevated plus maze for 5 min to be commensurate with other animals in its cohort.
To avoid increased freezing of the rodent to occur in the plus maze, noise and movements made by the experimenter must be kept at a minimum. In our laboratory, we hang signs outside the testing rooms to inform others that testing is in progress so that noise and disruptions are kept at a minimum. It is critical to decide upon the sex and reproductive age of animals to be used before initiating a study using the elevated plus maze.
Post-pubertal sex difference in the elevated plus maze has been reported 22 , Historically, many studies have used male rodents to avoid the influence of estrous cycle for elevated plus maze behavior 22 , 74 , For example, in our laboratory, we have consistently observed that young, adult intact female rats or mice in diestrus low estradiol, low progestins spent less time rats: However, the pattern of elevated plus maze behavior is different when rodents in proestrous high estradiol and progestins are tested; rodents in proestrous rats: Therefore, investigators must take into consideration that there may be different baseline elevated plus maze activity depending on the sex of experimental animals and estrous cycle stage in females, and design experiments using the elevated plus maze accordingly.
The following results exemplify data we have obtained using the elevated plus maze protocol, which is described in detail above, to investigate the anti-anxiety effects of progesterone 43 , The results we have obtained using the elevated plus maze to determine the effects of progesterone and its metabolites are robust and replicable.
Furthermore, similar to androgens, described above, progesterone is metabolized to a neuroactive steroid, called allopregnanolone, that positively modulates GABA A receptors and produces similar anxiolytic effects as benzodiazepines An experiment conducted in our laboratory using the elevated plus maze is described below. In this study, young adult 2—3 months old female rats and mice were ovariectomized and recovered from surgery for 1 week.
An observer, blind to the experimental condition of the experimental animal, recorded the behavioral data using the protocol described in detail above. Thus, we can conclude that progesterone can increase anti-anxiety-like behavior in the elevated plus maze. The elevated plus maze is a widely used behavioral assay for anxiety behavior of rodents. It is easy to use, can be fully automated and valid results can be obtained in a short, 5-min testing period.
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Abstract The elevated plus maze is a widely used behavioral assay for rodents and it has been validated to assess the anti-anxiety effects of pharmacological agents and steroid hormones, and to define brain regions and mechanisms underlying anxiety-related behavior.
Face validity of the elevated plus maze The elevated plus maze has face validity, which is the ability of a task to appear to measure what it is supposed to measure. Construct validity of the elevated plus maze The elevated plus maze has construct validity.
Predictive validity of the elevated plus maze The elevated plus maze has predictive validity, which is defined as the extent to which the dependent measure predicts behavior on a related measure. Effects of novel environment pre-exposure Pre-exposure to a different novel environment, such as an open field or hole-board task, has been used in studies assessing anxiety behavior of rodents.
Utility of a single test session in the elevated plus maze When assessing the anxiolytic properties of pharmacological agents, many investigators use pre-exposure to the elevated plus maze. Open in a separate window. General background information relating to the procedure Timing of testing: Mouse elevated plus maze Our maze is made of stainless steel, which is painted matte black, and consists of four arms two open without walls and two enclosed by Video-tracking system with computer interface and video camera In our laboratory, a video-tracking system e.
Data collection The primary method for data collection that is used in our laboratory is the use of the video-tracking system, described above, which automatically detects and records when rats or mice enter the open or closed arms of the maze and the time spent in each.
Make sure maze is cleaned and dried before use and that video-tracking system is ready to be used. Fill out data sheets with subject number of animal, date, coded condition and initialed by the experimenter before testing.
Bring rodent, which is in its individual temporary transport cage, into the behavioral testing room. Take rodent out of its cage and place at the junction of the open and closed arms, facing the open arm opposite to where the experimenter is.
Differences are observed when rodents are placed facing toward an open arm versus toward the closed arm 1. In our laboratory, rodents are placed on the maze facing the same open arm. Start the video-tracking system and a timer set for 5 min when the rodent is placed in the maze. It is not recommended that the video-tracking system is started before the animal is placed in the maze so that the behavior of each animal is consistently recorded for 5 min.
The video-tracking system will automatically record the number of entries made by the rodent onto the open and closed arms and the time spent on the open arm and closed arm. The experimenter should simultaneously record the number of arm entries and time spent in each open arm on the data sheets with a timer.
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