[Effect of filial imprinting procedure on cell proliferation in the chick brain]

Area of Science:

• Neuroscience
• Developmental Biology
• Animal Behavior

Background:

• Visual imprinting is a crucial learning process in precocial birds.
• The neural mechanisms underlying memory formation during imprinting are not fully understood.
• Investigating cell proliferation in the chick brain can elucidate imprinting-related neurogenesis.

Purpose of the Study:

• To test the hypothesis that memory formation during visual imprinting is linked to new cell generation in the domestic chick brain.
• To examine the temporal effects of imprinting on cell proliferation in specific brain regions.

Main Methods:

• Bromodeoxyuridine (BrdU) incorporation was used to measure cell proliferation.
• BrdU was injected before visual imprinting training in newborn domestic chicks.
• Cell counts were assessed 24 hours and 7 days post-training in various brain areas, including the intermediate medial mesopallium (IMM), arcopallium intermedium (AI), medial part of nidopallium and mesopallium (MNM), nidopallium dorso-caudalis (Ndc), hippocampus (Hp), and area parahippocampalis (APH).

Main Results:

• A significant increase in BrdU-positive cells was observed in the IMM 24 hours after imprinting.
• Seven days after training, no significant changes were found in the IMM.
• Conversely, a decrease in new cell numbers was noted in the MNM and Ndc compared to control groups 7 days post-training.

Conclusions:

• Visual imprinting influences the generation of new brain cells in young chicks.
• Imprinting exhibits opposing short-term and long-term effects on neurogenesis.
• This dual action may relate to imprinting's role in developing predispositions for recognizing natural parents.