Postnatal development of the dog pineal gland. Light microscopy

Area of Science:

• Veterinary Anatomy
• Histology
• Developmental Biology

Background:

• The canine pineal gland's development is not well-documented.
• Understanding pineal gland morphology is crucial for comparative anatomy and physiology.

Purpose of the Study:

• To describe the light microscopical morphology of the dog pineal gland from birth to adulthood.
• To identify key developmental stages and cellular changes.

Main Methods:

• Light microscopy was used to examine dog pineal gland samples.
• Histological sections were analyzed from the first postnatal day through maturity.

Main Results:

• Immature cells and mitotic figures were prevalent in the first postnatal week.
• Pigmented cells appeared in the first week, within the pineal gland and in extrapineal nodules.
• A cordonal pattern observed in the second week progressively disappeared, with adult cell types discernible from 20-30 days.
• Adult dog pineal glands showed a significant increase in size compared to neonatal stages.

Conclusions:

• The dog pineal gland undergoes significant morphological changes during postnatal development.
• Key cellular and structural transitions occur within the first month of life.
• This provides a foundational description for canine pineal gland histology.