Did you know that fruit flies can even become addicted to cocaine? By studying how these tiny creatures behave when exposed to cocaine, researchers can gain a better understanding of the neurological and behavioral mechanisms underlying addiction. In this talk, we'll explore how fruit flies have been used to study cocaine addiction and the new network-based measures that have been revealed through the analysis of their social interaction networks. This data-driven approach can help us better understand the genetic and environmental factors that influence both drug addiction and social behavior.

1. Networks,
Cocaine, and
Fruit Flies: A
Data-Driven
Approach
DSC Europe 2023
Milan Petrović

2. About me
PhD student specializing in complex networks
Faculty of Informatics and Digital Technologies,
University of Rijeka, Croatia
Complex networks, data science, machine learning
Interdisciplinary research
Social interaction networks of fruit flies

3. What is social interaction

4. But why fruit flies?
Life cycle ~ 10 days
Genetic manipulation
Similarity between humans and flies

5. Influence of isolation
• Isolation from the group increase METH self-administration in flies
• Social interaction as positive reinforcer in the drug addiction
-1.25
-1.00
-0.75
-0.50
-0.25
0.00
0.25
0.50
0.75
1.00
1.25
Day1 Day2 Day3
prefrence
uL/day/fly
without isolation with 2 days of isolation

6. Importance of Study
• Detect variations in social activity across different strains and
treatments.
• Proven usefulness in detecting genetic, environmental and
substance influences.
• Gene expression (foraging gene)
• Isolation
• Psychostimulants
A simple computer vision pipeline reveals the effects of isolation on social interaction dynamics in
Drosophila
The Drosophila melanogaster foraging gene affects social networks
A network-based analysis detects cocaine-induced changes in social interactions in Drosophila melanogaster

7. Experimental setup
• Used wild-type flies of CantonS
background.
• Flies bred at 25°C and 70% humidity
under a 12h light/12h dark cycle.
• 30 adult male flies (3–5 days old).
• Two treatments, a total of 20 groups
• One treatment transferred to regular
molasses food (CTRL), and another with
0.50 mg/mL cocaine-hydrochloride (COC).

8. Data Collection
• Observation of social interactions in a circular arena.
• Video recordings processed to determine individual trajectories.
• Manual verification to ensure the accuracy of fly identities.

9. Tracking
Caltech FlyTracker

10. Social space and interaction criteria
Automated identification of social interaction criteria in Drosophila melanogaster

11. Social Interaction Networks
• Creation of directed social interaction networks.
• Representation of social relationships (count and duration).
• Temporal analysis capturing evolving social dynamics.

12. Data Processing Pipeline
• Transformation of trajectory data.
• Calculation of distances, facing angles, and interaction times.
• Network analysis on local, middle and global levels

13. Results
A network-based analysis detects cocaine-induced changes in social interactions in Drosophila melanogaster

14. Communities
CTRL: HIGH MODULARITY
• many links within and few links between
COC: LOW MODULARITY
• few links within and many links between

15. Fragile X
• Collaboration with prof. Dragana Protić and her team from Institute of Pharmacology, Clinical
Pharmacology and Toxicology; Faculty of Medicine, University of Belgrade, Serbia
https://polyfrax.com/

16. What
next?

17. Thank you!
• milan.petrovic@uniri.hr
• Github: milanXpetrovic
• Faculty of Informatics and Digital Technologies
• Laboratory for behavioral genetics
• Laboratory for semantic technologies (337)
In collaboration with Ana Meštrović, Ana Filošević Vujnović, Franka Rigo, Rozi Andretić
Waldowski, Bobana Samardžija, Marta Medija