Hippocampus and homing in pigeons: left and right hemispheric differences in navigational map learning

Area of Science:

• Neuroscience
• Animal Behavior
• Avian Navigation

Background:

• Homing pigeons possess remarkable navigational abilities.
• The hippocampal formation (HF) is implicated in spatial learning and memory across species.
• Understanding the neural basis of avian navigation, particularly the role of the HF, is crucial.

Purpose of the Study:

• To investigate the role of the hippocampal formation (HF) in homing pigeon navigation.
• To determine if different hemispheres of the HF are specialized for distinct navigational tasks.
• To elucidate the neural mechanisms underlying map learning and local navigation in pigeons.

Main Methods:

• Unilateral ablation of the right or left hippocampal formation (HF) in young homing pigeons.
• A period of 3 months in an aviary for navigational map learning.
• Testing homing performance from distant, unfamiliar locations and near the loft.

Main Results:

• Pigeons with left HF ablation showed impaired navigational map learning and homing.
• Pigeons with right HF ablation showed impaired local navigation near the loft.
• Control and right HF-ablated pigeons successfully learned navigational maps, while left HF-ablated pigeons did not.

Conclusions:

• Navigational map learning in homing pigeons is critically dependent on the left hippocampal formation (HF).
• The right HF plays a significant role in local navigation, likely utilizing familiar landmarks.
• These findings demonstrate hemispheric lateralization of navigational functions within the pigeon's HF.