Abstract:
Microglia, as the resident macrophages of the brain, are essential for maintaining brain homeostasis. They shape neuronal circuits during development, survey their environment for debris or dead cells, as well as respond to infection and injury in the brain, among many other functions. However, their important role in neurodevelopment and synaptic plasticity and pathophysiology has not been fully defined, highlighting the need for further investigation. To gain a more comprehensive understanding of the role of microglia in these processes, we need to isolate microglia and characterize them genetically, metabolically, and functionally. However, the isolation of microglia from adult mice, especially from small brain structures, is challenging as they represent a small percentage of the total brain cells, and the yield of isolated microglia is often too low. Here, the magnetic isolation of microglia using CD11b(+) microbeads allows us to sort microglial cells from the hypothalamus of a freshly perfused adult mouse brain. The current method allows us to achieve relatively high purity and yield in a short period while maintaining cell viability.

Abstract:
Microglia are the macrophages of the central nervous system (CNS), implying their role in maintaining brain homeostasis. To achieve this, these cells are sensitive to a plethora of endogenous and exogenous signals, such as neuronal activity, cellular debris, hormones, and pathological patterns, among many others. More recent research suggests that microglia are highly responsive to nutrients and dietary variations. In this context, numerous studies have demonstrated their significant role in the development of obesity under calorie surfeit. Because many reviews already exist on this topic, we have chosen to present the state of our reflections on various concepts put forth in the literature, bringing a new perspective whenever possible. Our literature review focuses on studies conducted in the arcuate nucleus of the hypothalamus, a key structure in the control of food intake. Specifically, we present the recent data available on the modifications of microglial energy metabolism following the consumption of an obesogenic diet and their consequences on hypothalamic neuron activity. We also highlight the studies unraveling the mechanisms underlying obesity-related sexual dimorphism. The review concludes with a list of questions that remain to be addressed in the field to achieve a comprehensive understanding of the role of microglia in the regulation of body energy metabolism.