1. “There's always a pigeon That'll come shit on your hood”:
Hippocampal Formation in Homing Pigeon Sun Compass- Based Spatial Learning

2. Historical Aspect-Military
Ancient times
Persian King Cyrus sent information
Greeks sent news of Olympics victories
France used status and prestige
War times
1870 Franco Prussian war 4 month siege of Paris had 400 birds deliver over 115,000 messages
WWI Gen. John Pershing ordered development of pigeon communication system

3. Historical Aspect-Military
World War I and II
WWI
Over half million birds used
95% success rate (more accurate than wire service)
Cher Ami most famous
WWII
Germans had 50,000 pigeons ready
Americans rebuilt pigeon program
Used during radio silence times and as recon
English and Germans develop falcon program to intercept birds and communication
Pigeon Clip.
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4. BACKGROUND Mammalian and Bird HF homologous
Development
Connectivity
Neurochemistry
For birds, lesioning the hippocampus impairs landmark navigation
In particular, homing pigeons HF critical for navigation map learning, navigation by landmarks near and far.

5. Background
Pigeons in unfamiliar locations utilize navigational maps to determine location relative to their home
Enclosed areaHFL impair acquisition, HFR do not
Homing pigeons dependent on sun compass/magnetic field for sense of direction

6. materials N=60 homing pigeons (all have previous homing experience
3 groups=C, HFR, HFL
Ablations to left and right hippocampal regions were done through aspiration under anesthesia.
Sham were anaesthetized, incised, and sutured.
Training during sun visibility

7. Apparatus

8. PRE-TRAINING 1st day: Food visible in the goal boxes
2nd day: Food not visible in the goal boxes
Pigeon removed after all food eaten or after 30 min
3rd day: Food only in target goal box
Pigeon only removed if food found correction procedure

9. EXPERIMENTAL TRAINING
Ten trials per session
Each trial: pigeon allowed to enter 1 box and then removed
No correction procedure
Trial scored correct if pigeon chose same target box as before
Birds tested alternately if at same time (ITI around min)
Test probe=5 trials w/ no food reward

10. EXPERIMENT 1—No cues

11. Experiment 1…cont’d Pigeons housed for 6 days in light proof room
Artificial day started and ended 6 hrs before natural light phase
First 3 days: Pigeons fed normally
Last 3 days: Pigeons not given any food
Tested in arena w/o feature cues 5 times (unreinforced)

12. Experiment 2--cues

13. Experiment 2…cont’d Pigeons housed for 6 days in light proof room
Artificial day started and ended 6 hrs before natural light phase
Tested in arena 5 times (unreinforced) with the sun compass and feature cues in CONFLICT with each other

14. Experiment 3--rotation

15. Experiment 3—cont’d After training ended, pigeons given 1 test session
Associated feature cues rotated 90º
Test session had 5 trials (unreinforced) with the sun compass and feature cues in CONFLICT with each other.
**Did they do the 6hr light phase?

16. Experiment 4—w and w/o cues

17. Experiment 4—cont’d Pigeons housed for 6 days in light proof room
Artificial day started and ended 6 hrs before natural light phase
Tested in arena w/o feature cues
To demonstrate sun compass learning w/o feature cues
Tested in arena w/ 5 trials (unreinforced)

18. Histology and lesions Exp 1 and 2 pigeons sacrificed
Black area = damage common to 9/12 pigeons
Striped area = damage common to 4/12 pigeons

19. RESULTS

20. RESULTS

21. RESULTS

22. RESULTS

23. CUTE!!!

24. Discussion
Controls
Preferred sun compass based goals, esp seen during the 6hr phase shift
Preferred sun compass over feature cues in spatial learning and behavior

25. DISCUSSION HFL Pigeons
No indication that shifts in orientation was due to sun compass use
EXP 3 pigeons shifted mainly due to feature cues
Could also be relying on other information to guide their directions (EXP 1 birds learned tasks without feature cues)
Therefore, HFL pigeons had a sun compass learning deficit

26. DISCUSSION HFR Pigeons
In general, shifted direction appropriately according towards the sun compass
However, during presence of feature cues, HFR pigeons preferred use of feature cues vs. sun compass (ability for sun compass is still present
Therefore, ONLY the left HF is capable of supporting sun compass-based learning and plays the more important role in sun compass based spatial learning

27. DISCUSSION

28. CONCLUSIONS
Partial segregation of the spatial processing elements involved in sun compass based learning (via HL) and goal location w/in geometrical framework (via HR)
Lesioned HR had sun compass abilities but preferred feature cues when available
Relying on extra-hippcampal circuits when there are feature cues? Not relying on these circuits when there aren’t feature cues?
Lesioned HL impaired spatial cognition and prevented sun-compass based learning
Are there extra-hippocampal circuits? Or is it just the right region?

30. REFERENCES
Gagliardo, A., Ioale, P., Odetti, F., Bingman, V.P., Seigel, J.J., & Vallortigara, G. (2001). Hippocampus and homing in pigeons: left and right hemispheric differences in navigational map learning. European Journal of Neuroscience, 13,
Glagliardo, A., Vallortigara, G., Nardi, D., & Bingman, V.P. (2005). A lateralized avian hippocampus: preferential role of the left hippocampal formation in homing pigeon sun compass-based spatial learning. European Journal of Neuroscience, 22,
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