Neuroanatomical characterization of the Nmu-Cre knock-in mice reveals an interconnected network of unique neuropeptidergic cells

• Published in: Open biology Vol. 13; no. 6; p. 220353
• Main Authors: Medrano, Mireia, Allaoui, Wissal, Van Bulck, Mathias, Thys, Sofie, Makrini-Maleville, Leila, Seuntjens, Eve, De Vos, Winnok H, Valjent, Emmanuel, Gaszner, Bálazs, Van Eeckhaut, Ann, Smolders, Ilse, De Bundel, Dimitri
• Format: Journal Article
• Language: English
• Published: England Royal Society 01-06-2023; The Royal Society
• Subjects: Animals; Disease Models, Animal; Integrases - genetics; knock-in mouse model; Life Sciences; Mice; Neurobiology; neuromedin U; Neurons; Neurons and Cognition; neuropeptide; Neuropeptides - genetics; Peptide Hormones; ventromedial hypothalamic nucleus; ventromedial hypothalamic nucleus; neuromedin U; knock-in mouse model; neuropeptide
• ISSN: 2046-2441; 2046-2441
• DOI: 10.1098/rsob.220353

Neuromedin U (NMU) is an evolutionary conserved neuropeptide that has been implicated in multiple processes, such as circadian regulation, energy homeostasis, reward processing and stress coping. Although the central expression of NMU has been addressed previously, the lack of specific and sensitive tools has prevented a comprehensive characterization of NMU-expressing neurons in the brain. We have generated a knock-in mouse model constitutively expressing Cre recombinase under the
promoter. We have validated the model using a multi-level approach based on quantitative reverse-transcription polymerase chain reactions,
hybridization, a reporter mouse line and an adenoviral vector driving Cre-dependent expression of a fluorescent protein. Using the Nmu-Cre mouse, we performed a complete characterization of NMU expression in adult mouse brain, unveiling a potential midline NMU modulatory circuit with the ventromedial hypothalamic nucleus (VMH) as a key node. Moreover, immunohistochemical analysis suggested that NMU neurons in the VMH mainly constitute a unique population of hypothalamic cells. Taken together, our results suggest that Cre expression in the Nmu-Cre mouse model largely reflects NMU expression in the adult mouse brain, without altering endogenous NMU expression. Thus, the Nmu-Cre mouse model is a powerful and sensitive tool to explore the role of NMU neurons in mice.