Caffeine interferes embryonic development through over-stimulating serotonergic system in chicken embryo.

Area of Science:

• Developmental toxicology
• Neuroscience
• Pharmacology

Background:

• Caffeine's potential risks during pregnancy are a public health concern.
• Monoamine neurotransmitters play a crucial role in fetal neural development.
• Maternal-fetal interactions involving neurotransmitters may influence long-term mental and behavioral health.

Purpose of the Study:

• To investigate the effects of caffeine on the monoamine neurotransmitter system in developing chicken embryos.
• To assess caffeine's impact on neural tube development and serotonergic system integrity.

Main Methods:

• Utilized developmental chicken embryos as a model system.
• Administered varying dosages of caffeine (2.5, 5.0, and 10.0 μmol/egg).
• Assessed neural tube closure, measured levels of serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA), and analyzed TPH2 gene expression.

Main Results:

• Caffeine administration, even at sub-lethal doses, caused neural tube closure failure.
• Increased levels of serotonin (5-HT) and its metabolite 5-HIAA were observed at 10.0 μmol/egg.
• Caffeine treatment elevated TPH2 gene expression, indicating altered serotonergic activity.
• Caffeine accumulated in the embryonic brain without significant metabolism.

Conclusions:

• Caffeine exposure during embryonic development can lead to neural tube defects and disrupt the serotonergic system.
• These disruptions may increase the risk of teratogenicity and contribute to psychological and behavioral disorders later in life.
• The accumulation and lack of metabolism of caffeine in the embryonic brain may exacerbate adverse effects.