Material & Methods

Gryllus bimaculatus, n = 96.
Picture by npps48.

The model used was the Mediterrenean Field cricket.

My population was tested for:

  • boldness,
  • locomotor activity,
  • repetitively induced fear responses.

All the tests were performed once per day in the same arena.

Arena used to perform behavioural tests. The shelter was removed when the boldness test ended.

Boldness was measured by timing the latency to exit a shelter.
Activity was measured by counting the movements between sections, in which the arena was divided.
Boldness and activity were measured twice on two consecutive days.
Variation in fear responses was measured by timing the latency to exit the freezing behaviour induced by the tap of a pen on the bottom of the arena. Freezing was induced ten consecutive times.

Manipulation of octopamine was performed through injection of Octopamine-hydrochloride (Sigma-Aldrich) into the volume of 10 μl of phosphate-buffered saline (PBS). Control crickets were injected with only phosphate-buffered saline.