TrkB-expressing paraventricular hypothalamic neurons suppress appetite through multiple neurocircuits.

Abstract

The TrkB receptor is critical for the control of energy balance, as mutations in its gene (NTRK2) lead to hyperphagia and severe obesity. The main neural substrate mediating the appetite-suppressing activity of TrkB, however, remains unknown. Here, we demonstrate that selective Ntrk2 deletion within paraventricular hypothalamus (PVH) leads to severe hyperphagic obesity. Furthermore, chemogenetic activation or inhibition of TrkB-expressing PVH (PVHTrkB) neurons suppresses or increases food intake, respectively. PVHTrkB neurons project to multiple brain regions, including ventromedial hypothalamus (VMH) and lateral parabrachial nucleus (LPBN). We find that PVHTrkB neurons projecting to LPBN are distinct from those to VMH, yet Ntrk2 deletion in PVH neurons projecting to either VMH or LPBN results in hyperphagia and obesity. Additionally, TrkB activation with BDNF increases firing of these PVH neurons. Therefore, TrkB signaling is a key regulator of a previously uncharacterized neuronal population within the PVH that impinges upon multiple circuits to govern appetite.

• Authors: Juan Ji An, Clint E Kinney, Ji-Wei Tan, Guey-Ying Liao, Eric J Kremer, Baoji Xu
• Journal: Nature communications (Nat Commun) Vol. 11 Issue 1 Pg. 1729 (04 07 2020) ISSN: 2041-1723 [Electronic] England
• PMID: 32265438 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Membrane Glycoproteins
• Ntrk2 protein, mouse
• Protein-Tyrosine Kinases

Topics

• Animals
• Appetite (genetics)
• Feeding Behavior (physiology)
• Female
• Hyperphagia (genetics, metabolism)
• Membrane Glycoproteins (genetics, metabolism)
• Mice
• Mice, Inbred C57BL
• Mice, Transgenic
• Neurons (metabolism)
• Obesity (genetics, metabolism)
• Parabrachial Nucleus (cytology, metabolism, physiopathology)
• Paraventricular Hypothalamic Nucleus (cytology, metabolism)
• Protein-Tyrosine Kinases (genetics, metabolism)
• Ventromedial Hypothalamic Nucleus (cytology, metabolism)