Melatonin Effects on PI3K/Akt Pathway and Cognitive Function in Hypoxic Rat Hippocampal Neurons

Area of Science:

• Neuroscience
• Pharmacology
• Biochemistry

Background:

• Intermittent hypoxia (IH) can induce cognitive dysfunction.
• The PI3K/Akt signaling pathway plays a role in cellular responses to hypoxia.
• Melatonin is an antioxidant with potential neuroprotective effects.

Purpose of the Study:

• To investigate melatonin's effect on cognitive deficits caused by IH in rats.
• To determine if melatonin modulates the PI3K/Akt signaling pathway and antioxidant proteins (Nrf2, HO-1) in the hippocampus.
• To assess the role of PI3K inhibition in melatonin's effects.

Main Methods:

• Sixty-four male Wistar rats were exposed to IH or normoxia for up to 8 weeks.
• Melatonin or a PI3K inhibitor was administered intraperitoneally before IH exposure.
• Cognitive function was evaluated using the Morris water maze.
• Hippocampal protein expression (p-PI3K, p-Akt, Nrf2, HO-1) was analyzed via immunohistochemistry.

Main Results:

• IH significantly impaired cognitive function and altered protein expression over time.
• Melatonin treatment improved cognitive performance and increased p-PI3K, p-Akt, Nrf2, and HO-1 expression compared to IH alone.
• PI3K inhibition blocked the effects of melatonin on protein expression.
• Significant interactions between treatment and time were observed for protein expression.

Conclusions:

• Melatonin may protect against IH-induced cognitive dysfunction by upregulating the PI3K/Akt pathway and antioxidant proteins.
• The PI3K/Akt pathway is crucial for melatonin's neuroprotective effects against IH.
• These findings suggest a therapeutic potential for melatonin in conditions involving cognitive impairment due to hypoxia.