Age-Related Changes as the Primary Driver of Pineal Gland Involution—A Morphological Study in Health and Disease

The human pineal gland (PG) undergoes structural and cellular changes during the aging process, yet the underlying patterns and mechanisms remain insufficiently understood. In this study, we analyzed the lobular architecture and astrocytic network of the PG and identified two distinct pathways associated with normal aging. The first is characterized by an increase in astrocyte number within the pineal parenchyma, suggesting a compensatory role in supporting pinealocyte function. The second pathway involves disruption of the lobular structure, leading to a decline in the functional integrity of the gland. While pathological conditions such as neurodegenerative and psychiatric disorders may accelerate pineal degeneration and reduce melatonin production, our results suggest that normal aging is the principal factor driving this involutional process. These findings contribute to a deeper understanding of the morphological aging pathways of the pineal gland and their potential functional implications.