THE EFFECTS OF MELATONIN ADMINISTRATION AND CURIOSITY ACTIVATION ON HIPPOCAMPAL BETA-AMYLOID AND TAU PROTEIN LEVELS IN D‑GALACTOSE‑INDUCED AGING RAT MODEL

Brain aging is characterized by progressive structural and functional alterations, including hippocampal accumulation of beta‑amyloid and tau proteins that are central to Alzheimer’s disease pathology. Melatonin exhibits neuroprotective actions that may attenuate age‑related proteinopathy. Moreover, curiosity, an intrinsic cognitive‑motivational state, enhances neural stimulation and may increase resistance to age‑related neural decline. This study investigated the effects of melatonin administration and curiosity activation on the levels of hippocampal beta‑amyloid and tau proteins in D‑galactose‑induced aging rat model. Rats were randomly assigned to five groups: control, D‑galactose (150 mg/kg), D‑galactose plus melatonin (10 mg/kg), D‑galactose plus curiosity activation, and D‑galactose plus melatonin and curiosity activation. Treatments were administered once daily for eight weeks. Curiosity activation was induced using radial arm maze and novel object recognition tests. Hippocampal beta‑amyloid and tau protein levels were quantified by enzyme‑linked immunosorbent assay (ELISA). The results showed significant elevations in beta‑amyloid and tau levels in D‑galactose group compared with controls. Melatonin administration, curiosity activation, and their combined intervention significantly reduced levels of beta‑amyloid and tau proteins in the hippocampus. These findings suggest that melatonin and curiosity‑related behavioral activation, particularly when combined, may mitigate age‑related hippocampal accumulation of beta‑amyloid and tau proteins associated with Alzheimer’s disease, and may represent a potential preventive strategy.
Acknowledgement: This study was supported by research grant from HRH Princess Mahachakri Sirindhorn Medical Center, Faculty of Medicine, Srinakharinwirot University (Contract No.555/2568).