LimeLight
Video tracking for Open Field – Plus Maze – Radial Arm Maze – Zero Maze – Novel Object Recognition – Conditioned Place Preference
LimeLight is a video tracking system for behavioral experiments. It is extremely flexible and powerful, with a complete range of features, and yet it is easy to set up and operate, and it is affordable. Developed in close collaboration with behavioral neuroscientists, LimeLight gets high praise from its users.
Tracking. LimeLight can track up to 4 arenas at once. Use 1 camera for all 4 arenas (one in each quadrant of the image), or for maximum flexibility, 1 camera for each arena. No special lighting is necessary, and black or white animals are tracked automatically on almost any background. If you can see it, so can LimeLight. Any number of stationary items can be placed in the arena without affecting tracking. Collect images at up to 30 frames per second for one animal or up to 8 frames per second when tracking 4 arenas at once. Tracking is robust even at extremely low light levels so that the environment can be tailored to the animal’s needs, not the camera’s. Images are compressed on-the-fly and stored on the hard drive for later review and for off-line scoring of complex behaviors. All or part of the trial video can easily be exported in AVI or QuickTime format for presentation purposes.
Arena Setup. LimeLight simplifies the process of setting up grids and zones, but allows complete flexibility. Dedicated interfaces for Open Field testing (circular or square) and Elevated Plus Maze require only a few mouse clicks to configure. The Custom zone setup allows almost infinite flexibility for more specialized designs, such a novel object recognition or zero-maze, again with a simple click-and-drag interface. Zone configurations can be changed in the analysis phase, after the trials are recorded.
Behavior Scoring. User-defined behaviors can be scored either during a trial, or while viewing the trial from stored video. Store multiple sets of behaviors for rapid switching between experiments. Each behavior can be assigned a key stroke, or use the mouse to click buttons for scoring observed behaviors. For complex experiments, stored video can be reviewed repeatedly and at the users pace, each time adding in the scores for a different behavior or behavior set. Statistics on the scored behaviors can then be viewed and exported to Excel.
Stimulus Control. LimeLight has 8 output signals (TTL format) for controlling the experimental apparatus. The user can specify that a line be turned on when the animal enters a particular zone in the arena, with numerous options for sequencing. Initial grace period, stimulus duration, delay and lock-out are adjustable. The 8 output lines are provided on a plug-and-play USB interface.
High throughput. LimeLight was specifically designed for high throughput experiments. Some of our users record trials from hundreds of animal per day. All setup parameters are stored for rapid switching between experiments. Analysis windows and batch export allow rapid review of large numbers of trials.
Analysis. LimeLight excels at analysis. The main analysis window gives an informative overview of most aspects of a trial in graphical form. The display at the right, for example, shows a colormap of the time spent in each grid-square, and is instantly available for any animal in a data file. Video is also instantly available for playback for any animal.
Export zone-by-zone values for many different measures, or export summary data for all available measures and all recorded animals. Exported measurements are automatically displayed in a new window in Excel, as well as being saved to a text-based file. Collect data from any number of animals into a single data file and afterward sort animals into user-specified groups: When an Analysis is performed, data are reported for animals in each group, together with mean and standard deviation for the group as a whole. Analyses can also be prepared for user-defined portions of each trial. For example, one can split each trial into 2 equal intervals and analyze each interval separately. Analyses are designed in collaboration with our users and are tailored to the specific needs of each type of experiment. For all experiments, each analysis parameter can be exported by grid square or user-defined groups of grid squares, maze arm, or custom zone. Parameters include:
- Distance travelled in each region (cm or %)
- Time spent in each region (sec or %)
- Crossings into each region
- Body length from nose to base of tail (mm), together with stretch-attend bouts
- Pointing Direction (orientation)
- Mean distance from center
- Latency to Zone
- Distance and Velocity vs. time
- Statistics for scored behaviors (1st and 2nd order)
- Statistics on occurrence of stimuli (output control)
- Zone sequence
- Circling
- Rotation
Ease of use. LimeLight’s interface makes it a pleasure to use (and we are not the only ones to say so). Dozens of shortcuts make traversing the many features of the program nearly instantaneous. Most displays, for example, can be double-clicked to display more details of an analysis or to change the displayed parameters, without searching through the menus for the relevant item.
