The Melatonin Signaling Pathway in a Long-Term Memory In Vitro Study

Area of Science:

• Neuroscience
• Cell Biology
• Molecular Biology

Background:

• Cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) phosphorylation is crucial for memory processing.
• Melatonin's role in increasing CREB expression is known in vivo, but the in vitro signaling pathway remains unclear.

Purpose of the Study:

• To elucidate the in vitro signaling pathway between melatonin receptor 1 (MT1) and CREB.
• To investigate melatonin's effect on long-term memory processing in aged HT-22 cells.

Main Methods:

• Utilized HT-22 cells to study melatonin's signaling pathway.
• Investigated the phosphorylation cascade involving Raf, ERK, p90RSK, CREB, and BDNF expression.
• Assessed the involvement of calcium, JNK, and AKT pathways.
• Examined melatonin's effects on aged HT-22 cells.

Main Results:

• Melatonin activated the MT1 receptor, initiating a signaling cascade.
• The pathway involved phosphorylation of ERK, p90RSK, CREB, and increased BDNF expression.
• Calcium, JNK, and AKT pathways were not implicated in melatonin's signaling.
• Melatonin increased p-CREB and BDNF levels in aged HT-22 cells.

Conclusions:

• Melatonin mediates the MT1-ERK-p90RSK-CREB-BDNF signaling pathway in an in vitro model of long-term memory processing.
• Melatonin enhances CREB and BDNF expression, suggesting a role in cellular aging and memory.
• This study provides in vitro evidence for melatonin's role in regulating CREB signaling pathways relevant to long-term memory.