The development and function of microglia, the resident immune cells of the mammalian central nervous system (CNS), are critical for maintaining CNS homeostasis and responding to various pathological conditions. Microglia, which originate from the yolk sac and populate the CNS before its vasculature forms, are highly dynamic and adaptable cells that can transform morphologically and functionally to suit their environment. They play a crucial role in neuronal survival, death, and synaptic pruning, as well as in the clearance of dead cells and debris. Microglial dysfunction has been linked to neurological disorders such as obsessive-compulsive disorder (OCD) and Rett syndrome, where mutations in genes like *Hoxb8* and *MECP2* disrupt their normal functions. In neurodegenerative diseases like Alzheimer's disease (AD) and Parkinson's disease (PD), microglia can become reactive and contribute to chronic inflammation and cognitive decline. The precise role of microglia in these diseases is complex and involves both protective and detrimental functions, with their phagocytic capacity and cytokine production playing key roles. Understanding the molecular mechanisms and signaling pathways that regulate microglial function is essential for developing therapeutic strategies to combat neurological disorders.The development and function of microglia, the resident immune cells of the mammalian central nervous system (CNS), are critical for maintaining CNS homeostasis and responding to various pathological conditions. Microglia, which originate from the yolk sac and populate the CNS before its vasculature forms, are highly dynamic and adaptable cells that can transform morphologically and functionally to suit their environment. They play a crucial role in neuronal survival, death, and synaptic pruning, as well as in the clearance of dead cells and debris. Microglial dysfunction has been linked to neurological disorders such as obsessive-compulsive disorder (OCD) and Rett syndrome, where mutations in genes like *Hoxb8* and *MECP2* disrupt their normal functions. In neurodegenerative diseases like Alzheimer's disease (AD) and Parkinson's disease (PD), microglia can become reactive and contribute to chronic inflammation and cognitive decline. The precise role of microglia in these diseases is complex and involves both protective and detrimental functions, with their phagocytic capacity and cytokine production playing key roles. Understanding the molecular mechanisms and signaling pathways that regulate microglial function is essential for developing therapeutic strategies to combat neurological disorders.