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Ablation of Oxytocin Neurons Causes a Deficit in Cold Stress Response

The paraventricular nucleus (PVN) is a critical locus of energy balance control. Three sets of neurons in the PVN are involved in regulating energy balance: oxytocin-expressing neurons (OXT-neurons), thyrotropin-releasing hormone–expressing neurons, and corticotrophin-releasing hormone–expressing ne...

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Detalles Bibliográficos
Autores principales: Xi, Dong, Long, Caela, Lai, Meizan, Casella, Alex, O’Lear, Lauren, Kublaoui, Bassil, Roizen, Jeffrey D.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Endocrine Society 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5686635/
https://www.ncbi.nlm.nih.gov/pubmed/29264556
http://dx.doi.org/10.1210/js.2017-00136
Descripción
Sumario:The paraventricular nucleus (PVN) is a critical locus of energy balance control. Three sets of neurons in the PVN are involved in regulating energy balance: oxytocin-expressing neurons (OXT-neurons), thyrotropin-releasing hormone–expressing neurons, and corticotrophin-releasing hormone–expressing neurons. To examine the role of OXT-neurons in energy balance, we ablated these neurons in mice by injecting diphtheria toxin into mice possessing both the oxytocin promoter driving cre expression and a cre-inducible diphtheria toxin receptor. Immunohistochemistry and real-time reverse transcriptase polymerase chain reaction confirmed that this injection caused a significant decrease in PVN OXT-neurons and OXT-mRNA abundance. OXT-neuron ablation did not alter food intake, weight, or energy expenditure at room temperature on either chow or a high-fat diet. To further characterize OXT-neuron–ablated mice, we examined their response to 1) intraperitoneal cholecystokinin (CCK) injection and 2) thermogenic stress. OXT-neuron–ablated mice had a blunted decrease in feeding response to CCK. When exposed to the extreme cold (4°C) for 3 hours, OXT-neuron–ablated mice had significant decreases in both rectal and brown adipose tissue temperature relative to controls, which was rescued by OXT treatment. Thermographic imaging revealed that OXT-neuron–ablated mice had increased body surface temperature. Thus, we report that OXT-neuron ablation shows no role for OXT-neurons in energy homeostasis at neutral temperature but reveals a heretofore unappreciated role for OXT-neurons and oxytocin specifically in regulating the thermogenic stress response.