Plasticity of microglia.

Microglial cells are the scions of foetal macrophages which invade the neural tube early during embryogenesis. The nervous tissue environment instigates the phenotypic metamorphosis of foetal macrophages into idiosyncratic surveilling microglia, which are generally characterised by a small cell body and highly ramified motile processes that constantly scan the nervous tissue for signs of changes in homeostasis and allow microglia to perform crucial homeostatic functions. The surveilling microglial phenotype is evolutionarily conserved from early invertebrates to humans.

Microglial heterogeneity in aging and Alzheimer's disease: Is sex relevant?

Neurodegenerative diseases and their associated cognitive decline are known to be more prevalent during aging. Recent evidence has uncovered the role of microglia, the immunocompetent cells of the brain, in dysfunctions linked to neurodegenerative diseases such as is Alzheimer's disease (AD). Similar to other pathologies, AD is shown to be sex-biased, with females being more at risk compared to males.

Estrogen-dependent sex difference in microglia in the developing brain of Japanese quail (Coturnix japonica).

Brain sexual differentiation is a developmental process leading to the establishment of stable neural sex differences. In birds and rodents, this process is largely driven by estrogens during a critical period. In rodents, estrogens drive the masculinization of the brain, a process that partly depends on microglia.