Biology subjects

Hecksher-Sorensen, J.

Publications and source records attributed to Hecksher-Sorensen, J..

4 recordsLinked to original sources

bioRxiv2026

Ventral pallidal GABAergic neurons control hedonic feeding and obesity

Food intake is governed by two interacting drives. The homeostatic hunger drive regulates food intake to fulfill caloric needs while the hedonic drive promotes intake of palatable foods outside of caloric need. It is unclear which neural substrates can control the hedonic drive and thereby reduce overeating of palatable foods and associated obesity. Here, we show that ventral pallidal GABAergic neurons (VPGABA) preferentially control hedonic feeding and are necessary for diet-induced obesity in mice. Stimulating VPGABA neurons drove robust consumption of high-fat diet and liquids, but not regular laboratory chow. Despite driving intake of palatable foods, VPGABA neurons are relatively insensitive to homeostatic signals - they express few hunger-hormone receptors and are not activated by ghrelin administration or fasting. Single-cell calcium imaging revealed stronger engagement of VPGABA neurons during long vs short feeding bouts, suggesting control over bout duration, which has been linked to palatability. This was confirmed with closed-loop optogenetic stimulation. Finally, taCasp3-mediated ablation of VPGABA neurons reduced intake of palatable liquids and blocked high-fat diet-induced obesity without impacting homeostatic feeding. Together, these findings establish VPGABA neurons as a neural population that preferentially controls hedonic over homeostatic feeding and can be leveraged to block obesity in mice.

neuroscience↗

bioRxiv2024

Adult oligodendrogenesis gates arcuate neuronal glucose sensing through remodelling of the blood-hypothalamus barrier via ADAMTS4

Brain glucose sensing is critical for survival during hypoglycaemia and tunes the level of defended blood glucose, which goes up in diabetes. Neuronal glucose sensing neurons and mechanisms have been identified, but how these neurons access blood concentrations of glucose to adjust their output and maintain glucose homeostasis is unclear. Here, we demonstrate that adult oligodendrogenesis in the median eminence (ME) is modulated by changes in circulating glucose levels and rapidly upregulated by hypoglycaemia. We show that genetic blockade of new OL production in adult mice impairs the regulation of glucose homeostasis, the integrity of the ME blood-hypothalamus barrier, and neuronal glucose sensing in the arcuate nucleus of the hypothalamus (ARH). Unexpectedly, functional integrity of adult-formed myelin is not required for the maintenance of glucose homeostasis. Instead, newly formed OLs exert their glucoregulatory actions via the synthesis of A disintegrin and metallopeptidase with thrombospondin motifs 4 (ADAMTS4), a metallopeptidase expressed exclusively by OLs and dependent on adult OL genesis to maintain its expression in the ME. Both lack of Adamts4 and ADAMTS4 gain-of-function are associated with impaired glucose homeostasis and remodelling of the blood-hypothalamus barrier, indicating that optimal ADAMTS4 expression is required for the integrity of vascular permeability and normal glycaemic control. Finally, we show that ME ADAMTS4 expression is regulated by changes in peripheral glycaemia and is dysregulated in diabetes, providing a mechanism by which ME OLs contribute to the regulation of glucose homeostasis.

neuroscience↗

bioRxiv2022

Whole-Brain Three-Dimensional Imaging of RNAs at Single-Cell Resolution

Whole-brain three-dimensional (3D) imaging is desirable to obtain a comprehensive and unbiased view of architecture and neural circuitry. However, current spatial analytic methods for brain RNAs are limited to thin sections or small samples. Here, we combined multiple new techniques to develop TRIC-DISCO, a new pipeline that allows imaging of RNA spatial distributions in whole adult mouse brains. First, we developed Tris-mediated retention of in situ hybridization signal during clearing (TRIC), which produces highly transparent tissue while maintaining the RNA signal intensities. We then combined TRIC with DISCO clearing (TRIC-DISCO) by controlling temperature during the in situ hybridization chain reaction (isHCR) to ensure uniform whole-brain staining. This pipeline eliminates the requirements for both strict RNase-free environments and workflow-compatible RNase inhibitors. Our TRIC-DISCO pipeline enables simple and robust, single-cell, whole-brain, 3D imaging of transcriptional signatures, cell-identity markers, and noncoding RNAs across the entire brain.

neuroscience↗

bioRxiv2019

GLP-1R is downregulated in beta cells of NOD mice and T1D patients

Glucagon-like peptide 1 (GLP-1) is produced by L cells in the small intestine in response to ingested glucose and increases insulin release from pancreatic beta cells by activation of its cognate receptor (GLP-1R). Stimulation of this receptor also contributes to increased beta cell survival and regeneration. We have found that pancreatic beta cells from Non Obese Diabetic (NOD) mice express significantly lower levels of GLP-1R than C57BL/6 mice, leaving the NOD beta cells with an impaired response to GLP-1 stimulation. The lower expression appears to be caused by accelerated degradation of GLP-1R in the beta cells, a process that can be reversed by inhibiting trafficking to the lysosome. Importantly, our results appear to translate to the human disease since we also observed significantly lower expression of the GLP-1R in pancreatic islets from donors with type 1 diabetes. These results suggest that beta cell physiology may play a role in susceptibility to autoimmune inflammation.

physiology↗