Organization of sympathetic innervation of interscapular brown adipose tissue in the mouse.

The interscapular brown adipose tissue (iBAT) is under sympathetic control, and recent studies emphasized the importance of efferent sympathetic and afferent sensory or humoral feedback systems to regulate adipose tissue function and overall metabolic health. However, functional studies of the sympathetic nervous system in the mouse are limited, because details of anatomy and fine structure are lacking. Here, we used reporter mice for tyrosine hydroxylase expressing neurons (TH:tomato mice), iDISCO tissue clearance, confocal, lightsheet, and electron microscopy to clarify that (a) iBAT receives sympathetic input via dorsal rami (instead of often cited intercostal nerves); (b) dorsal rami T1-T5 correspond to the postganglionic input from sympathetic chain ganglia (stellate/T1-T5); (c) dorsal rami serve as conduits for sympathetic axons that branch off in finer nerve bundles to enter iBAT; (d) axonal varicosities show strong differential innervation of brown (dense innervation) versus white (sparse innervation) adipocytes, that surround the core iBAT in the mouse and are intermingled in human adipose tissues, (e) axonal varicosities can form neuro-adipocyte junctions with brown adipocytes.

Sympathetic innervation of the mouse kidney and liver arising from prevertebral ganglia.

The sympathetic nervous system (SNS) plays a crucial role in the regulation of renal and hepatic functions. Although sympathetic nerves to the kidney and liver have been identified in many species, specific details are lacking in the mouse. In the absence of detailed information of sympathetic prevertebral innervation of specific organs, selective manipulation of a specific function will remain challenging.

Maternal cold exposure induces distinct transcriptome changes in the placenta and fetal brown adipose tissue in mice.

Background: Brown adipose tissue (BAT) is specialized to dissipate energy in the form of heat. BAT-mediated heat production in rodents and humans is critical for effective temperature adaptation of newborns to the extrauterine environment immediately after birth. However, very little is known about whether and how fetal BAT development is modulated in-utero in response to changes in maternal thermal environment during pregnancy.

Sympathetic innervation of inguinal white adipose tissue in the mouse.

Adipose tissue plays an important role in metabolic homeostasis and its prominent role as endocrine organ is now well recognized. Adipose tissue is controlled via the sympathetic nervous system (SNS). New viral, molecular-genetic tools will soon allow a more detailed study of adipose tissue innervation in metabolic function, yet, the precise anatomical extent of preganglionic and postganglionic inputs to the inguinal white adipose tissue (iWAT) is limited.

Sympathetic innervation of the interscapular brown adipose tissue in mouse.

The recent discovery of significant brown fat depots in adult humans has revived discussion of exploiting brown fat thermogenesis in the control of energy balance and body weight. The sympathetic nervous system (SNS) has a key role in the activation of brown fat and functional mapping of its components will be crucial for the development of specific neuromodulation techniques. The mouse is an important species used for molecular genetic modulations, but its small size is not ideal for anatomical dissections, thus brown fat innervation studies are mostly available in larger rodents such as rats and hamsters.

Preoptic leptin signaling modulates energy balance independent of body temperature regulation.

The adipokine leptin acts on the brain to regulate energy balance but specific functions in many brain areas remain poorly understood. Among these, the preoptic area (POA) is well known to regulate core body temperature by controlling brown fat thermogenesis, and we have previously shown that glutamatergic, long-form leptin receptor (Lepr)-expressing neurons in the POA are stimulated by warm ambient temperature and suppress energy expenditure and food intake. Here we further investigate the role of POA leptin signaling in body weight regulation and its relationship to body temperature regulation in mice.

The Hypothalamic Preoptic Area and Body Weight Control.

The preoptic area (POA) of the hypothalamus is involved in many physiological and behavioral processes thanks to its interconnections to many brain areas and ability to respond to diverse humoral factors. One main function of the POA is to manage body temperature homeostasis, e.g.

Galanin-Expressing GABA Neurons in the Lateral Hypothalamus Modulate Food Reward and Noncompulsive Locomotion.

The lateral hypothalamus (LHA) integrates reward and appetitive behavior and is composed of many overlapping neuronal populations. Recent studies associated LHA GABAergic neurons (LHA ), which densely innervate the ventral tegmental area (VTA), with modulation of food reward and consumption; yet, LHA projections to the VTA exclusively modulated food consumption, not reward. We identified a subpopulation of LHA neurons that coexpress the neuropeptide galanin (LHA ).