Knowledge Base

Problem

Users want to use EthoVision's live tracking to trigger optogenetic stimulation (e.g., laser or LED) in real time based on animal location or behavior, and are unsure what hardware and software setup is required.

Details

Applies to EthoVision XT setups requiring closed-loop optogenetic stimulation. Users typically need to trigger a laser or LED controller via TTL signal based on zone entry, behavior classification, or a trial event. Distinct from the existing 'Dual-Channel Optogenetic Stimulation' article, which covers two-zone TTL wiring; this article covers the general hardware/software framework for any optogenetic triggering setup.

Solution

1. **Confirm your license includes Trial & Hardware Control.** Check Help > About EthoVision > License Info for 'Trial Control' or 'Hardware Control' modules.
2. **Hardware required:**
- A Noldus I/O box (USB or serial model) to provide TTL output lines.
- A custom Ethernet-to-BNC cable, or a Noldus opto-isolator unit, to connect the I/O box output to the optogenetics controller input.
- Verify the BNC input voltage/logic requirements of your laser/LED controller match the I/O box output (typically 0–5 V TTL).
3. **Software setup in EthoVision:**
a. Go to **Setup > Experiment Settings > Trial & Hardware Control**.
b. Add the I/O box as a hardware device and configure the relevant TTL output channel.
c. Create a Trial Control rule: define the trigger condition (e.g., animal enters a specific zone) and set the action to activate the TTL output on the configured channel.
d. Set stimulation duration using a sub-rule or a timed off-action.
4. **Reference the EthoVision Application Manual** chapter on pairing EthoVision with optogenetics for detailed wiring diagrams and worked examples.
5. Test the setup with a dummy load before connecting live optogenetics hardware to confirm TTL timing and polarity.