1) The document describes experiments using a conditioned odor avoidance (CODA) task in mice to investigate avoidance behavior and fear generalization as an animal model for PTSD. 2) The CODA task involves pairing an odor cue (ethanol) with footshocks and then testing avoidance of the odor versus a neutral odor over time. 3) The experiments found that after an incubation period, mice developed "generalized" avoidance of both odors, resembling the avoidance seen in PTSD patients, and this avoidance was reduced by diazepam, suggesting it involves associative and non-associative components.

1. Fear incubation leads to generalized avoidance in an animal model of PTSD AG Wotjak Data Presentation – December 2008 Fabrício Pamplona, Dr. AG Wotjak Max Planck Institute of Psychiatry - Munich

2. Avoidance is a natural defensive response

3. Avoidance is a natural defensive response

4. Anxiety disorders from an ethological perspective Adapted from Gray J.A. & McNaughton N., The Neuropsychology of Anxiety (2001), Oxford press. DANGER TO AVOID TO APPROACH avoidable unavoidable avoidable unavoidable Phobia flight escape avoidance Panic fight freeze Anxiety risk assessment behavioral inhibition Depression behavioral supression

6. PTSD mouse model Siegmund A & Wotjak CT., J Psychiatr Res. (2007) 41:848-60. Slide kindly provided by Yulia Golub

7. Develop a behavioral task to investigate avoidance behavior and fear generalization in the PTSD mouse model. Objective

8. 30 cm 30 cm 30 cm 30 cm 10 cm 10 cm 10 cm C.OD.A. apparatus Conditioned Odor Avoidance (C.OD.A.)

9. Home cage bedding (Safety signal) Odor stimulus (Acetate 1%) Odor stimulus (Ethanol 70%) Conditioned Odor Avoidance (C.OD.A.)

10. Home cage bedding (Safety signal) Guillotine doors Guillotine doors Odor stimulus (Acetate 1%) Odor stimulus (Ethanol 70%) Conditioned Odor Avoidance (C.OD.A.)

11. Home cage bedding (Safety signal) Guillotine doors Guillotine doors Odor stimulus (Acetate 1%) Odor stimulus (Ethanol 70%) Mouse at the Starting point Conditioned Odor Avoidance (C.OD.A.)

13. Experiment 1: Establishment of the conditioned ethanol avoidance 0.7mA, 2s C.OD.A. EtOH EtOH vs Acetate 7 days

14. Experiment 2: C.OD.A. in PTSD mice (fear incubation) 1.5mA, 2s C.OD.A. EtOH EtOH vs Acetate 2 or 28 days

15. Experiment 2: C.OD.A. in PTSD mice (fear incubation) 1.5mA, 2s C.OD.A. EtOH EtOH vs Acetate 2 or 28 days

16. Experiment 2: C.OD.A. in PTSD mice (corticosterone release) 1.5mA, 2s EtOH EtOH vs Acetate exposure 28 days

17. Experiment 3: Role of safety component (nest) in C.OD.A. Evaluation of the first 5 min (habituation) 1.5mA, 2s C.OD.A. EtOH EtOH vs Acetate 28 days

18. Experiment 4: Relation with trauma intensity 0, 0.5, 0.75, 1.5mA, 2s C.OD.A. EtOH EtOH vs Acetate 28 days

19. Experiment 5: Role of context memory – High and Low freezers 1.5mA, 2s C.OD.A. EtOH EtOH vs Acetate 28 days 1 day 3 min LF/HF

20. Experiment 6: Relation with other PTSD parameters Parameters selected for bivariate correlations and PCA: Freezing: - Chamber (trauma context) - Cylinder (new environment) - Tone (sensitization) - Hexagon (grid) Startle: - Baseline startle (105 dB, 115 dB) - Tone-enhanced startle (%TES) CODA: - Latency to the first entry -Time in EtOH, Acetate and Nest compartments

21. Intra-task bivariate correlations Experiment 6: Relation with other PTSD parameters

22. Experiment 6: Relation with other PTSD parameters Principal components analysis

23. Experiment 7: Understanding avoidance: Preventive Extinction 1.5mA, 2s C.OD.A. EtOH EtOH vs Acetate 25 days Day 2-4: 3 or 30 min 1 day 3 min

24. Experiment 7: Understanding avoidance: Preventive Extinction 1.5mA, 2s C.OD.A. EtOH EtOH vs Acetate 25 days Day 2-4: 3 or 30 min 1 day 3 min

25. Experiment 9: Understanding avoidance: Apparatus habituation

26. Experiment 9: Understanding avoidance: Apparatus habituation

27. Experiment 10: Understanding avoidance: Habituation + Extinction

28. Experiment 10: Understanding avoidance: Habituation + Extinction

29. Experiment 11: Pharmacological validation: Diazepam effects

30. Experiment 12: Pharmacological validation: Fluoxetine effects

32. Fabricio Pamplona People directly involved in the experiments Vincenzo Micale Yulia Golub Cristoph Thoeringer Kathrin Henes Wolfgang Plendl Carsten Wotjak Cristoph Mauch