Neurodegenerative conditions also result in an enhanced expression of ERα in neurons and in increased expression of ERα and ERβ in astrocytes. Thus, oestra¬diol synthesized by brain aromatase may activate ERα-associated neuroprotective signalling pathways in neurons and activate ERα and ERβ signalling in astro¬cytes to modulate neuroinflammation, oedema and the release of neuroprotective factors. In addition, locally produced oestradiol may also target ERs in other cell types, such as microglia, oligodendrocytes or endothelial cells. Further studies should determine whether neurodegenerative conditions regulate other ERs that medi¬ate neuroprotective actions of oestradiol, such as GPER or Gq-mER.