Stress Duration Drives Lasting Suppression of Courtship in Male Fruit Flies
Tokyo Metropolitan University — New research sheds light on how stress can have long-lasting effects on behavior, even in fruit flies. A team of researchers has discovered that the duration of confinement stress directly dictates how long male Drosophila flies suppress their courtship behavior.
"The duration of confinement influenced the duration of courtship suppression: 10-minute confinement had no effect, 30 or 60 minutes caused temporary suppression, and 7 or 24 hours led to suppression lasting at least five days."
Confinement: A Matter of Time
The study reveals a clear dose-response relationship between stress and behavioral change:
- No Effect: A brief, 10-minute confinement produced no change in courtship behavior.
- Temporary Suppression: Confinement for 30 or 60 minutes led to a temporary pause in courtship.
- Long-Term Suppression: A full day (7 or 24 hours) of confinement resulted in a suppression of courtship that persisted for at least five days.
The Chemical Key: Dopamine
Researchers found the root of this persistent behavioral change at the molecular level. Dopamine was identified as the key neurotransmitter specifically responsible for the persistence of the suppression. Notably, it is not involved in the initial, temporary suppression triggered by shorter stress periods. This points to a distinct biological pathway for establishing long-term behavioral changes versus short-term reactions.
Brain Region Pinpointed
The critical effects of dopamine were traced to specific receptors in the mushroom body, a well-known region of the insect brain that is central to sensory processing and learning. This discovery provides a specific neural target for understanding how stress-induced changes become ingrained.
Support
This research was made possible by JSPS KAKENHI grants 21H02528 and 21H00434.