The pineal gland in ageing and alzheimer's disease: age-related molecular changes.

Pineal calcification was initiated as early as age 3 and showed progressive accumulation with accompanying cellular loss during ageing.

• 54 total human pineal gland specimens were collected and analyzed histopathologically.
• 47 specimens were categorized into five age groups: 0–20, 21–40, 41–60, 61–80, and 81–100 years.
• Calcification onset was detected as early as age 3.
• Progressive accumulation of calcification was accompanied by cellular loss across age groups.

Sexual dimorphism was observed in the pineal gland, with female-predominant patterns including lipofuscin deposition and pineal cysts, and male-predominant characteristics including GFAP immunoreactivity and connective tissue expression.

• Lipofuscin deposition was identified as a female-predominant feature.
• Pineal cysts were identified as a female-predominant feature.
• Glial fibrillary acidic protein (GFAP) immunoreactivity was identified as a male-predominant characteristic.
• Connective tissue expression was identified as a male-predominant characteristic.
• The authors described this as 'a remarkable degree of sexual dimorphism.'

Amyloid-beta (Aβ) deposition in the pineal gland was positively correlated with age and was markedly elevated in individuals with Alzheimer's disease.

• Aβ deposition was detected within the pineal gland tissue.
• Phosphorylated Tau (P-Tau) was also detected within the pineal gland.
• Aβ deposition showed a positive correlation with age across the five age groups.
• Aβ levels were markedly elevated in the AD group compared to controls.
• 7 cases with confirmed AD-related neuropathological changes were compared to 7 matched controls.

Individuals with Alzheimer's disease exhibited marked pineal cellular depletion and elevated GFAP expression compared with matched controls.

• The AD group consisted of 7 cases with confirmed AD-related neuropathological changes matched to 7 controls.
• Pineal cellular depletion was described as 'marked' in the AD cohort relative to controls.
• GFAP expression was elevated in the AD group compared to controls.
• Histopathological analyses were used to assess cellular and molecular changes.

Cerebrospinal fluid analysis revealed significantly reduced melatonin levels in the Alzheimer's disease cohort.

• Melatonin levels were measured in cerebrospinal fluid (CSF) samples.
• Melatonin was described as 'significantly reduced' in the AD cohort.
• This finding was reported alongside structural and molecular changes in the pineal gland in AD.