Shared Autonomic Pathways Connect Bone Marrow and Peripheral Adipose Tissues Across the Central Neuraxis.

Area of Science:

• Neuroscience
• Adipose Tissue Biology
• Metabolic Regulation

Background:

• Bone marrow adipose tissue (BMAT) exhibits unique metabolic responses compared to white adipose tissue (WAT).
• The central nervous system (CNS) influences adipose tissue function via sympathetic neurons.
• Understanding BMAT regulation may offer insights into metabolic disorders like obesity and anorexia.

Purpose of the Study:

• To investigate the autonomic innervation of BMAT.
• To identify central neural pathways regulating BMAT.
• To compare BMAT innervation with that of peripheral WAT.

Main Methods:

• Quantification of tyrosine hydroxylase (TH)-positive nerve fibers in mouse tibia.
• Retrograde viral tract tracing using pseudorabies virus (PRV) from BMAT and inguinal WAT.
• Identification of PRV-infected neurons in CNS regions.

Main Results:

• BMAT exhibits significant autonomic innervation, with nerve-associated adipocytes increasing distally along the tibia.
• Common central neuroanatomic pathways were identified for both BMAT and iWAT.
• Dual-infected neurons suggest coordinated regulation of multiple sympathetic outputs.

Conclusions:

• This is the first quantitative report on BMAT autonomic innervation.
• Shared central pathways indicate coordinated regulation between BMAT and peripheral adipose tissues.
• Findings provide a foundation for understanding CNS control of BMAT in metabolic health.