Knowledge Base

Data Preparation

Track Editing

Choose Acquisition > Edit Tracks. You can fix tracking errors but normally you will not need to edit your data.

Track Smoothing

Choose Acquisition > Track Smoothing Profile > open one of the two Track Smoothing Profiles:

• No Filter
• MDM 0.2 cm – In this Track Smoothing Profile, the Direct Minimal Distance Moved filter is used, with an MDM of 0.2 cm.

Use Smoothing when you want to eliminate small movements, such as body wobbling during locomotion, that might affect dependent variables such as total distance moved.

Selecting Data

Choose Analysis > Data Profile. The template contains two data profiles:

• All Data – This data profile contains all data.
• Treated vs. Control – This data profile contains two Results containers with data for the treated animals and the control animals. This way you create groups of tracks to obtain group statistics for both groups.

Analysis Profiles

Default Analysis Profiles

The template experiment contains three analysis profiles:

• Distance and Velocity – In this profile, the total Distance Moved and the mean Velocity are calculated for the center-point.
• In Zones – In this profile, the Frequency, Duration and Latency to First for all zones (arms and goal zones) are calculated for the center-point. A visit to a previously chosen arm is considered a working memory error. Normal healthy young rats will perform this task almost perfectly every time, so will visit each arm and goal zone only once.
• Zone Transitions – In this profile, the Frequency of zone transitions from the center zone to any arm is calculated for the center-point.

For all statistics, the group means with standard errors are also calculated.

Testing Working Memory

Time Taken to Obtain All Rewards

The most basic test conducted using the radial-arm maze is to bait the ends of all of the arms with the reward and record the time taken to obtain all the rewards. The following procedure applies to trials where all baited arms were visited.

1. In the Analysis profile, choose Target visits and errors.
2. In the Target zones box, select all the zones that were baited.
3. Under Calculate Statistics for, select Target first visits.
4. Click the Trial Statistics tab and select Latency to Last.

Incorrect Arm Choices

To obtain a reward, an animal must remember which arm(s) it visited previously and not re-visit those arms.

1. In the analysis profile, choose Target visits and errors.
2. In the Target zones box, select all the zones that were baited.
3. Under Calculate Statistics for, select Target revisits.
4. Click the Trial Statistics tab and select Frequency.

Percentage of Correct Choices

One of the parameters described in the Unit 8.5A of Current Protocols in Neuroscience (Wenk, 2004) to calculate performance of all groups is: the percentage of correct choices made in each test session in relation to the total number of arms entered.

1. In the analysis profile, choose Target visits and errors.
2. In the Target zones box, select all the zones that were baited.
3. Under Calculate Statistics for, select Target first visits and Target revisits.
4. Click the Trial Statistics tab and select Frequency.
5. You can calculate the percentage of correct choices with: Target first visits / (Target first visits + Target revisits) * 100

Testing Reference Memory

The radial-arm maze may also be used to test reference memory by only baiting some arms of the maze. In training trials, the reward is placed consistently from trial to trial for the same animal, but its placement is varied from animal to animal. In the test trials, the time to acquire the reward and the number of incorrect choices (i.e., entering an unbaited arm or re-entering a baited arm) are analyzed.

Time Taken to Obtain the Rewards

1. In the analysis profile, choose Target visits and errors.
2. In the Target zones box, select all the zones that were baited.
3. Under Calculate Statistics for, select Target first visits.
4. Click the Trial Statistics tab and select Latency to Last.

Number of Entries into Unbaited Arms

1. In the analysis profile, choose Target visits and errors.
2. In the Target zones box, select all the zones that were baited.
3. Under Calculate Statistics for, select Not-target first visits and Not-target revisits.
4. Click the Trial Statistics tab and select Frequency.

Note: Re-entries into baited arms are considered working memory errors.

Because the arms chosen to be baited differ between animals, make copies of the dependent variable Target visits and errors and edit the arms that are considered targets. Rename the variables (right-click the variable name and select Rename) and give them logical names (e.g. Baited arms 1-3-6-8). In the analysis results, locate the variable that applies to specific subjects.

To easily locate which subjects were assigned to which baited arms in your results table, create an independent variable in the Trial List which specifies which arms were baited. This variable can then be included in the results table (in the Statistics and Charts screen, choose Show/Hide > Independent Variable).

Integrated Visualization

Choose Analysis > Results > Plot Integrated Data. Select a trial from the list on the tool bar. Choose a data profile and an analysis profile from the tool bar.

Heatmaps

Choose Analysis > Results > Plot Heatmaps. Next, click Plot Heatmaps. Use heatmaps to visualize the location of the subject during the test.

Calculating Statistics

Choose Analysis > Results > Statistics & Charts. Select an analysis profile from the list on the tool bar, then click Calculate.

Choose Analysis > Export > Statistics. Choose whether you want to export the statistics per trial, or the combined statistics of groups of trials.

Source: EthoVision XT 18 - Application Manual, Noldus Information Technology