Long-lasting induction of Notch2 in the hippocampus of kainate-treated adult mice

Notch proteins are involved in cell fate specification during development in tissues including brain. Little is known about their function in adulthood. Recently, Notch receptors have been hypothesized to play a role in neurodegeneration and in particular in Alzheimer's disease (Notch1) and CADASIL (Notch3). Here we show that another family member (Notch2) is constitutively expressed in adult mouse hippocampus in DG and not in CAI and CA3 neurons. Treatment with kainic acid resulted in marked Notch2 induction in pyramidal neurons of CAI and in a subpopulation of CA3 neurons surviving the lesion and protein expression was still detectable 6 weeks after drug treatment. These results suggest Notch2 involvement in the response of postmitotic neurons to excitotoxic stimuli.