Structural, morphometric and immunohistochemical study of the rabbit accessory olfactory bulb

Area of Science:

• Neuroscience
• Olfactory System Research
• Animal Model Studies

Background:

• The accessory olfactory bulb (AOB) integrates signals from the vomeronasal system (VNS), crucial for semiochemical detection.
• Rabbit models are used for chemocommunication studies, but detailed AOB knowledge is lacking.
• Understanding rabbit AOB topography, lamination, and neurochemistry is essential.

Purpose of the Study:

• To characterize the neurochemical properties, topography, and lamination of the rabbit accessory olfactory bulb (AOB).
• To identify unique features of the rabbit AOB compared to other mammalian species.
• To investigate sex-based differences in AOB structure.

Main Methods:

• Histological stainings including lectin labeling (UEA-I, BSI-B4, LEA).
• Immunohistochemical analysis using markers for G proteins (Gαi2/Gαo), OMP, GAP-43, GLS, MAP-2, GFAP, CB, and CR.
• Morphometric analysis of AOB structure and cell density.

Main Results:

• Anteroposterior zonal expression of Gαi2/Gαo indicates a conserved double-path vomeronasal reception in Lagomorpha.
• Characterization of AOB strata and principal components revealed unique features, including four neuronal clusters (γ and δ groups) in the white matter.
• Significant sex differences in principal cell numerical density were observed, with higher values in females, contrasting with rats.

Conclusions:

• The rabbit AOB exhibits a highly developed and specialized structure with unique features.
• The findings underscore the importance of chemocommunication in rabbits.
• This detailed characterization provides a foundation for future VNS research in rabbits.