ZENK expression in a restricted forebrain area correlates negatively with preference for an imprinted stimulus

Area of Science:

• Neuroscience
• Ethology
• Animal Behavior

Background:

• Sexual imprinting is a critical learning process in avian development.
• This imprinting is linked to irreversible dendritic spine reduction in the LNM and MNM forebrain areas.
• The neural basis of imprinting recall in adulthood remains incompletely understood.

Purpose of the Study:

• To investigate the activation of LNM and MNM in adult male zebra finches when exposed to imprinted stimuli.
• To determine if brain area activation correlates with sexual preference after cross-fostering and imprinting.

Main Methods:

• Comparing ZENK expression in LNM and MNM of adult male zebra finches under different rearing conditions (own species vs. foster species).
• Assessing sexual preference using choice tests between conspecific and heterospecific females.
• Measuring brain activation via ZENK protein expression as a proxy for neural activity.

Main Results:

• Adult males reared by own species showed lower LNM/MNM activation when exposed to conspecific females compared to heterospecific females.
• Males cross-fostered by Bengalese finches exhibited higher LNM activation when exposed to zebra finch females.
• Higher LNM activation in cross-fostered birds tended to correlate negatively with preference for zebra finch females.

Conclusions:

• Early rearing environment influences adult brain responses to sexual imprinting stimuli.
• The LNM and MNM show differential activation patterns related to sexual preference, potentially reflecting more complex neuronal networks in cross-fostered birds.
• The negative correlation suggests specialized roles for LNM and MNM in processing imprinting information and preference.