Summary: The text discusses the significance of microglia, the brain's immune cells, in the development and progression of neurological diseases such as Alzheimer's, Parkinson's, and multiple sclerosis. Microglia play a crucial role in maintaining brain health by clearing debris and supporting neural function, but they can also become overactivated and contribute to neuroinflammation and neuron damage. Recent research has highlighted the dynamic nature of microglia, showing that they can shift between different activation states in response to changes in the brain microenvironment. Understanding these different activation states and how they contribute to disease pathology could provide valuable insights for developing targeted treatments for neurological diseases. Additionally, the emerging field of neuroimmunology is shedding light on the complex interactions between the brain and the immune system, paving the way for new therapeutic approaches to modulate microglial activity and potentially halt the progression of neurodegenerative disorders.