Knowledge Base

Differential Stimulation Depending on Zone

Aim

To give a pulse sequence with frequency fA when the subject is in zone A, and a pulse sequence with a frequency fB when the subject is in zone B.

Prerequisites

In the Arena Settings, you have defined two non-adjacent zones, A and B.

Procedure

1. Create new Trial Control Settings.
2. In the main Trial Control procedure, right after the Start Trial box, define an External command box to initialize the port for the Pulser.
3. Add a Time condition and set it to 2 seconds.
4. Add one External command, to the program C:\Windows\System32\cmd.exe with the line options: /C echo S>com[port number] (for example, /C echo S>com3). This instruction cancels the current pulse sequence definition stored in the Pulser in case you have used other definitions in a previous trial.
5. Add one Hardware command to set Output 1 to Low.
6. Create two Subrules, one for zone A and the other for zone B. In the main Trial Control sequence, after the Start track box, insert the two reference boxes. For both Reference boxes, select Repeat indefinitely.
7. In each Subrule, define the following instructions as described in the notes below.

Subrule Instructions

Each Subrule contains the following action boxes:

• Box a: In Zone Condition — Is the animal in zone A (or B)? (Current = true)
• Box b: Time Condition — Wait 1 second.
• Box c: External command — Define the pulse sequence.
• Box d: Custom Hardware Action — Set Output 1 High.
• Box e: In Zone Condition — Is the animal NOT in the zone? (Current = true)
• Box f: Custom Hardware Action — Set Output 1 Low.
• Box g: External command to C:\Windows\System32\cmd.exe with line option /C echo S>com[port number] — stops the pulse sequence definition and ensures the Pulser listens to the next definition when the subject enters the other zone.

These instructions check that the animal is in a particular zone (a). If it is, after one second (b) the corresponding pulse sequence is defined (c) and the Pulser is triggered (d). When the animal leaves the zone (e), stimulation stops (f) and the sequence definition is canceled (g). If the animal enters the other zone, the instructions in the other Subrule after (b) will be executed and the corresponding stimulation starts.

Notes

• Important: Do not use zones that are adjacent; always leave some space between the two zones.
• The 1-second Time condition (box b) has been inserted in both Subrules to ensure that there is enough time between the reset of the Pulser port at the end of one Subrule (box g) and the new pulse sequence definition in the other Subrule (box c) when the animal switches from one zone to the other.
• You need as many Subrules as there are trigger zones.

Multiple Simultaneous Stimulations in One Arena

Aim

To generate different pulse sequences and send them simultaneously to different subjects in one arena.

Note: Using multiple Pulsers is necessary when stimulation in two or more subjects can occur at the same time.

Basic Steps

1. Install the driver for the Pulser on the EthoVision XT computer.
2. Configure the driver for a specific Pulser (COM port). When connecting multiple Pulsers to the EthoVision XT computer, the Device Manager shows multiple instances of Prizmatix DVR (COM[n]) or USB Serial Port (COM[n]). Repeat this procedure for each instance.
3. Connect the Trig. In port of each Pulser/PulserPlus device to a TTL port of the USB-IO box.
4. In EthoVision XT (Experiment Settings), assign a TTL port to Pulser 1, another TTL port to Pulser 2, and so on. Tip: Rename the Device IDs to something descriptive, such as Pulser 1 and Pulser 2.
5. In EthoVision XT (Arena Settings), click the Arena-Hardware Mapping button. Add two devices and assign them to the arena.
6. In EthoVision XT (Trial Control Settings), for each Pulser, initialize the COM port and define the pulse sequence. Repeat this procedure for each Pulser.

Details

For each Pulser, define three External command Action boxes in a linear sequence before the Start track box:

• One for initializing the port (Procedure 1 - Initialize the COM port)
• One for stopping previous definitions (for example, from a previous trial)
• One for defining the pulse sequence (Procedure 2 - Define the pulse sequence)

In this example:

• Pulser 1 is set to a pulse sequence of 20 ms on and 20 ms off (25 Hz stimulation; boxes A for initialization and C for pulse definition).
• Pulser 2 is set to a pulse sequence of 10 ms on and 10 ms off (50 Hz stimulation; boxes D and E).

Note that actions are separated by Time conditions of 1–2 seconds. Complete your Trial Control procedure to the right of the Start track box. In this example, the Subrule triggers the Pulser for 1 second of stimulation with an interval of 5 seconds.

Notes

• Different protocols must be defined with different Subrules. For example, create Subrule 1 for controlling Pulser 1 and Subrule 2 for controlling Pulser 2.
• Tip: When using multiple Pulsers, it is convenient to use batch files. For example, the instructions for stopping sequence definitions for com3 and com5 would be:
  • echo S>com3
  • echo S>com5
  Enter these instructions in a text file and rename it with the extension .cmd. Then, instead of single instructions, create an External command pointing to this .cmd file.
• Important: Test the system thoroughly before running real experiments. When using multiple Pulsers, more time may be needed to initialize the ports. If the Pulser does not respond, the 2-second waiting time may not be sufficient. Set a longer time, such as 5 seconds, if needed.

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