Integration of Nutrient Sensing in Fish Hypothalamus

Area of Science:

• Neuroendocrinology
• Fish Physiology
• Metabolic Regulation

Background:

• Hypothalamic integration of metabolic and endocrine signals controlling food intake is poorly understood in fish.
• Nutrient sensing pathways involving glucose, fatty acids, and amino acids play a role in appetite regulation.

Purpose of the Study:

• To summarize current knowledge on hypothalamic signaling pathways regulating food intake in fish.
• To identify research gaps in understanding fish appetite control mechanisms.

Main Methods:

• Mini-review of existing literature on hypothalamic nutrient sensing and signaling in fish.
• Analysis of molecular pathways including protein kinases and transcription factors.
• Examination of neuropeptide gene expression related to feeding behavior.

Main Results:

• Nutrient sensing activates AMP-activated protein kinase (AMPK) inhibition and protein kinase B (Akt)/mechanistic target of rapamycin (mTOR) activation.
• These pathways modulate transcription factors like cAMP response-element binding protein (CREB), forkhead box01 (FoxO1), and brain homeobox transcription factor (BSX).
• Changes in transcription factors influence the expression of neuropeptides (NPY, AgRP, POMC, CART) to regulate food intake.

Conclusions:

• The hypothalamic network for food intake regulation in fish involves nutrient sensing, kinase signaling, and transcription factor modulation.
• Further research is needed to fully elucidate these complex interactions and their role in fish appetite control.