Brown adipose tissue changes in anencephalic infants. Image analysis study

Area of Science:

• Neonatal physiology
• Endocrinology
• Developmental biology

Background:

• Brown adipose tissue (BAT) plays a crucial role in non-shivering thermogenesis in newborns.
• The central nervous system, particularly the diencephalon, is traditionally thought to regulate BAT metabolism.
• Anencephaly, a congenital disorder characterized by the absence of a major portion of the brain, offers a unique model to study neural control of metabolic processes.

Purpose of the Study:

• To investigate the role of the diencephalon in the activation of brown adipose tissue (BAT) metabolism in liveborn infants.
• To determine if peripheral mechanisms alone can activate BAT lipolysis in the absence of a developed diencephalon.
• To compare intrauterine lipid storage in BAT between anencephalic and control infants.

Main Methods:

• Morphological examination of perirenal brown adipose tissue (BAT) in 49 liveborn anencephalic infants (lifespan 2 hours to 6 days).
• Comparative analysis using 187 full-term infants as controls.
• Image analysis to assess lipid storage in BAT cells of infants who died within 24 hours.

Main Results:

• Morphological evidence indicated active and marked lipolysis in the BAT of a significant number of anencephalic infants.
• These findings suggest that BAT metabolism activation, leading to lipolysis, can occur independently of a diencephalic pathway.
• No significant differences in intrauterine lipid storage within BAT cells were observed between anencephalic and control infants who died within 24 hours of birth.

Conclusions:

• Activation of brown adipose tissue (BAT) metabolism and lipolysis in newborns does not strictly depend on diencephalic pathways.
• Peripheral mechanisms appear to play a significant role in regulating BAT activity in the neonatal period.
• The intrauterine development and lipid storage in BAT are comparable between anencephalic and control neonates.