Sympathetic Wiring of Adipose Tissue

ended

Obesity is a metabolic disorder with unmet medical intervention strategies, for which a therapy is urgently needed. The Domingos Lab recently discovered that sympathetic (SNS) neuro-adipose junctions mediate lipolysis and fat mass reduction (Zeng et al., 2015). Thus, direct and targeted activation of SNS inputs to adipose tissues (AT) could represent a new strategy for the induction of fat loss that would circumvent central leptin resistance as well as historical challenges associated with drug delivery across the blood-brain-barrier. While it is known that the autonomic nervous system (ANS) plays a critical role in energetic metabolism through both its sympathetic and parasympathetic (PNS) branches; the mechanisms that underlie the development of the autonomic innervation of AT remain completely unexplored. Both the parasympathetic and sympathetic systems develop before birth, and autonomic nerve fibers can be observed in various peripheral organs as early as mid-gestation (Black, 1978; Burris and Hebrok, 2007; Rinaman and Levitt, 1993) although as AT originates at late gestation it is unclear how this late stage targeting may occur and how disruption to this process may impact metabolic profiles later in life. Although it has recently gained acceptance as an important endocrine organ, the cellular architecture of AT also remains elusive, as well as how this may be altered past hyperplasia and hypertrophy in pathological states. This has been due to the amorphous and unclearly defined nature of the tissue that becomes deformed and disrupted by classical dissection. The advent of whole body tissue clearing techniques allows us for the first time to study the architecture of AT and its inputs obviating the need for dissection and sectioning.