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WaterMaze by Actimetrics

Video Tracking System for the Morris Water Maze

WaterMaze, designed in collaboration with Richard Morris (University of Edinborough), is an entirely new concept for taking the strain out of running Morris water maze experiments. WaterMaze incorporates a unique Project Manager for designing and executing complex experiments with multiple animals, starting points and platform positions. Reference memory, working-memory and other designs in which trials are interleaved in different ways can be accommodated easily. Once the Project parameters are specified, each day WaterMaze tells the user which animal to run next and to which platform. Even the most complex experiments can be run accurately and efficiently, for high-throughput experiments.

WaterMaze’s analysis capabilities are unparalleled. Analyses can be viewed for single trials or exported for multiple trials directly to Excel (WaterMaze even opens Excel for you). Scan through hundreds of trials easily with clickable animal and trial lists. Parameters include thigmotaxis, Moser’s zones, Whishaw’s corridor, Gallagher’s proximity, quadrant times and crossings and more. Suggestions for new analyses from our users are regularly incorporated. Swim paths can be exported to standard drawing programs. Movies of each trial can be stored and viewed in the WaterMaze Analysis windows or exported to PowerPoint and other presentation software.

WaterMaze’s tracking is robust and easy to set up with standard CCD cameras and video boards. No special lighting or video-processing hardware is necessary. Landmarks or other cues of any color can be arranged in and around the pool without affecting tracking. Multiple remote control switches can be placed around the pool, and the program can control multiple On-Demand (Atlantis) Platforms. Movies of each trial can be stored for later review or for export in QuickTime format to PowerPoint or other presentation software.

Click here for a fact sheet on setting up and running a watermaze apparatus, written by Dr. Richard Morris, the originator of the Morris Water Maze.

WaterMaze goes far beyond existing programs in its ease of use and flexibility. Because it is designed in close consultation with users, WaterMaze is integrated seamlessly with the experiment. It is already in use in excellent laboratories in academia and in industry, including the laboratory where the watermaze was originally developed, and is poised to become the industry standard.

The WaterMaze Project Manager#

The Project Manager keeps track of complex trial sequences for up to 100 animals at a time. The sequence of trials, including different starting positions, maximum trial durations and platform locations, can be specified independently for each animal. Or set up the sequence for one animal and easily copy its sequence to other animals. The program can be set such that each animal gets all its daily trials together before the next animal is run, or with all animals being trained on one trial before they are moved on to the next.

No matter how complex the experiment is, the Project Manager keeps track and tells the user at the start of each day how many trials are to be run for each animal. Then, through the course of a day’s experiment, the program prompts the user for each animal in turn, showing on the live video image where the platform should be placed and where the animal should be released. The user is free to concentrate on animal behavior, not on animal bookkeeping. If necessary, preset sequences can be overridden and trials performed in any user-specified order. At the end of each trial, data are saved in prenamed files automatically. Problem animals can be removed from the project at any time with the click of a button. Or animals that have reached a learning criterion can be tagged and the program will automatically remove them from further training.

For all its flexibility, WaterMaze is easy to use. Because we are WaterMaze users as well as designers, we have built the features to match the daily routine of running experiments. Controls and menus are placed in logical and intuitive arrangements, so that even a complex protocol can be set up in a few minutes. Online Help windows are provided throughout the program.

WaterMaze Analysis#

The large image below shows a full-sized screen-shot of the Trial Viewer window. On the left is the clickable list of animals in this project, with one animals selected for display. To the right of that is the list of all trials for the selected animal, one of which has been selected. The path and analyses for this trial are shown to the right. The path window contains the Pool outline (large blue circle), the Platform position (small blue circle), the Path (yellow dots on blue outline), adjustable Thigmotaxis corridor (yellow circle) and adjustable Whishaw’s corridor (yellow box). The colors of many the elements of the window can be changed by the user. The Save Picture button exports the picture to a post-script file, which is readable by most presentation graphics programs. Below the path window are the parameters of the various analyses, including quadrant analysis, duration, speed, direction at a specified time and Moser’s zones (not shown). A portion of a trial (specified in seconds or % duration) may be selected for analysis.

From a separate Export window, any combination of analysis parameters can be exported to a spreadsheet (or directly to Excel) for selected subsets of trials. Trials can be selected individually from clickable lists as shown below, or in groups on the basis of target platform, animals, etc. WaterMaze can also calculate a density map of the time spent in each point in the maze for selected groups of animals.

Double clicking on any trial in the trial list brings up the stored video of the trial in a separate window. The video can be easily exported to a QuickTime file for presentation in PowerPoint or other presentation software.

WaterMaze Tracking#

WaterMaze uses a state-of-the-art image-processing software and video-capture card. Images can be acquired at up to 30 frames per second. The program identifies the animal whether it is lighter or darker than the background. A unique algorithm screens out changing shadows and changing lighting conditions that might occur during the trial. On-line interpolation identifies and smoothes occasional loss of signal that can occur if an animal swims briefly underwater or under hanging cue objects. The path taken can be displayed in real time as the trial proceeds. No special lighting is needed for WaterMaze to track animals. A few standard incandescent or halogen lamps placed strategically around the pool are sufficient. A special set-up window can be used to measure the evenness of lighting across the pool surface, which helps to eliminate deep shadows.

The image below is a screen shot of the tracking window. The yellow cursor shows the computer’s determination of current position. The yellow dots show the path.

At the end of each trial, the experimenter can type in notes concerning the trial just completed. The trial can be stopped manually or automatically when the animal reaches the platform. The trial is then saved, again either manually or automatically after a set interval. The program then indicates which animal should be run next, to which platform location and from which starting position.

Remote switches can be used to start, stop and save trials. Multiple switches for each function can be placed around the pool if desired. With the program in auto-sequence mode and auto-save mode, multiple trials can be performed without touching the computer’s mouse or keyboard.

Ordering WaterMaze#

Provided components:#

  • USB Camera with zoom lens
  • WaterMaze data collection and analysis software
  • Digital input/output interface (USB) for Atlantis control and remote switch input (see below)
  • Remote switch
  • On-line manual

System requirements#

Remote Switches and Atlantis Control#

  • Switch inputs can be configured for start and stop functions. Switches are connected through the interface box. Multiple switches for each function can be wired in parallel and placed at multiple locations around the pool.
  • The digital interface board also supports control of Atlantis or On Demand platforms. These platforms sit far below the surface until the program detects that the animal has remained over the platform for a pre-specified time period. The platform then rises up to the surface. Use of the on-demand platform prevents the animal from using a random search strategy for finding the platform.