Knowledge Base

Introduction

EthoVision XT can be used in learning tests, such as the water maze test and the conditioning tests (e.g., Pham et al., 2009).

The Trial and Hardware Control module of EthoVision XT can be used to operate hardware devices to be used in both classical and operant conditioning tests. In the latter, an action of the animal produces a result, for example, pressing a lever results in the food dispenser dropping a food pellet. This and other hardware actions (such as, turning on a light when the animal enters the shelter, or closing the door of a radial maze when the animal has exited that arm) can be operated through the Trial and Hardware Control in EthoVision XT.

Learning can be demonstrated by a change in the frequency of the animal's action over time. For example, when the animal is presented with an aversive stimulus every time it performs a certain action, the performance of the action will likely decrease over time because the animal tries to avoid the negative stimulus.

To be able to operate hardware devices with EthoVision XT you need:

• The Trial and Hardware Control Module: This module allows you to control hardware devices from within EthoVision XT.
• The USB-IO Box: This is the device that connects the EthoVision XT PC with external hardware devices such as the sound and light devices of PhenoTyper or a third-party hardware device.

This document describes how to set up EthoVision XT using Trial and Hardware Control in an operant conditioning test in PhenoTyper.

PhenoTyper

PhenoTyper is an instrumented cage to measure and test the behavior of laboratory rodents.

If you want to use EthoVision XT to operate a third-party hardware device, please contact Noldus Information Technology (www.noldus.com).

To see how a test with PhenoTyper is carried out in EthoVision XT, see the sample experiment PhenoTyper hardware XT180 on the downloads section of the Noldus website (my.noldus.com). In EthoVision XT, choose File > Restore Backup and select this file. See also the document Description of Sample Experiments of EthoVision XT.pdf for more information.

Fear Conditioning Test

In the fear conditioning test, you can use EthoVision XT to automatically detect freezing behavior as a measure of conditioned fear.

References

• Liu, W., Wang, X., Zhang, R., and Zhou, Y. (2009) Effects of postnatal exposure to methylmercury on spatial learning and memory and brain NMDA receptor mRNA expression in rats. Toxicology Letters, 230–235.
• Pham, J., Cabrera, S.M., Sanchis-Segura, C., and Wood, M.A. (2009) Automated scoring of fear-related behavior using EthoVision software. Journal of Neuroscience Methods, 323–326.

Physical Setup

The following suggestions are meant to optimize tracking:

• The camera should have a good view of the entire region the animals can be in (for zones like the shelter where the animal is not visible, you can define hidden zones).
• The lighting should be as even as possible throughout the arena and should be diffuse, so as not to cast strong shadows (which might be tracked instead of the animal).
• The background should contrast with the animal. If necessary use a different setup for light and dark colored animals.
• Either make sure the sides of the box are not reflective (e.g., sanding), or exclude the sides from the arena. If your objects are close to the sides then you will need to track the animal when it is against the side (so the camera sees the side instead of the base behind the animal).
• If you want to use the Deep Learning technique to track the subject's nose, keep in mind that there are additional requirements. Among other things, you need a powerful graphics card. See Deep Learning: Requirements and Limitations in the EthoVision XT Help.

For More Information

• About PhenoTyper: See the PhenoTyper - EthoVision XT 18 - Reference Manual.
• About Using Hidden Zones: See the section Shelters and Other Hidden Zones in the EthoVision XT Help.

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