Hippocampal Formation in Homing

Pigeon Sun Compass-Based Spatial Learning

Ancient timesPersian King Cyrus sent informationGreeks sent news of Olympics victoriesFrance used status and prestige

War times1870 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

World War I and IIWWI

Over half million birds used 95% success rate (more accurate than wire service) Cher Ami most famous

WWIIGermans had 50,000 pigeons readyAmericans rebuilt pigeon programUsed during radio silence times and as reconEnglish and Germans develop falcon program

to intercept birds and communication Pigeon Clip.

World of Wings Center

Mammalian and Bird HF homologousDevelopmentConnectivityNeurochemistry

For birds, lesioning the hippocampus impairs landmark navigation

In particular, homing pigeons HF critical for navigation map learning, navigation by landmarks near and far.

Pigeons in unfamiliar locations utilize navigational maps to determine location relative to their home

Enclosed areaHFL impair acquisition, HFR do not

Homing pigeons dependent on sun compass/magnetic field for sense of direction

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

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 boxPigeon only removed if food found correction procedure

Ten trials per session Each trial: pigeon allowed to enter 1

box and then removedNo correction procedureTrial scored correct if pigeon chose

same target box as before Birds tested alternately if at same

time (ITI around 15-20 min) Test probe=5 trials w/ no food reward

Pigeons housed for 6 days in light proof roomArtificial 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)

Pigeons housed for 6 days in light proof roomArtificial 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

After training ended, pigeons given 1 test sessionAssociated 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?

Pigeons housed for 6 days in light proof roomArtificial 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)

Exp 1 and 2 pigeons sacrificed

Black area = damage common to 9/12 pigeons

Striped area = damage common to 4/12 pigeons

ControlsPreferred sun compass based goals, esp

seen during the 6hr phase shiftPreferred sun compass over feature cues in

spatial learning and behavior

HFL PigeonsNo indication that shifts in orientation was

due to sun compass useEXP 3 pigeons shifted mainly due to feature

cuesCould 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

HFR Pigeons In general, shifted direction appropriately

according towards the sun compassHowever, 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

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 availableRelying 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 learningAre there extra-hippocampal circuits? Or is it

just the right region?

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, 1617-1624.

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, 2549-2559.

World of Wings http://www.pigeoncenter.org/militarypigeons.html