Knowledge Base

EthoVision XT can control a laser or LED light source for optogenetics, using time- or behavior-based triggers. For example, stimulation can be activated when the animal enters a specific zone.

Note: EthoVision does not pulse the laser directly. If pulsing (e.g., 20 Hz) is needed, a pulse generator is required. EthoVision can trigger the start/stop of this generator.

Required Components

The full system includes:

• EthoVision XT and its host computer
• Trial & Hardware Control Module
• USB IO Box or Mini IO Box (via USB)
• Laser or high-intensity LED source
• Pulse generator
• Fiber optics, connectors, cannulae (user-supplied)

You will need a TTL cable with an RJ45 connector on one end and a BNC (or compatible) connector on the other, connecting the IO box to the pulse generator (or directly to the laser).

Basic Setup in EthoVision

• In Experiment Settings, enable Use of Trial Control Hardware.
• Click Settings and select the appropriate IO box (USB or Mini USB). For the used TTL port, set Custom Hardware as the device type.
• In Arena Settings, click Arena-Hardware Mapping. Add and assign your device to Arena 1. Repeat for multiple arenas as needed.
• Use the Test function in the Arena-Hardware Mapping window to confirm connectivity:
  • Output 1 High – Turns device ON
  • Output 1 Low – Turns device OFF

Pulse Generator Configuration

Most pulse generators respond to a 5V TTL signal. Settings vary by model:

Pulse Mode: Fixed-duration pulse train

• Prizmatix Pulser: “Execute pulse sequence each time after trigger(s)”
• AMPI Master-8/9: “Train”
• Agilent Waveform Generator: “Triggered Burst Mode”

Gate Mode: Continuous pulse during trigger HIGH

• Prizmatix Pulser: “Execute pulse sequence after trigger HIGH, stop when LOW”
• AMPI Master-8/9: “Gate”
• Agilent Waveform Generator: “External Gated Burst Mode”
• Plexon PlexBright: “Edge Digital Input” (Use one trigger input for ON, another for OFF)

Trial Control Settings in EthoVision

Use the Trial Control feature to define stimulation timing. Events are shown as a flowchart:

Example: Simple timed stimulation (5 min pre-stim, 1 min stim, 5 min post-stim):

Repeated Stimulation

To repeat events, use a Sub-Rule loop:

• Pre-stimulation: 5 minutes
• Sub-rule: 2 min ON, 2 min OFF, repeated 3 times

Zone-Based (Place Preference) Stimulation

Stimulation starts/stops depending on the animal's zone (e.g., Left = ON, Right = OFF). The sub-rule runs continuously, and a time limit controls total duration:

Additional Triggering Options

Triggers for stimulation are not limited to zones. You can also use:

• Activity level
• Velocity
• Turning angle
• External sensors (e.g., lever presses, nose pokes)

This allows for highly flexible behavior-based stimulation and inhibition protocols.