GAD1 and Alzheimer disease: Interestingly, a similar decline of cortical GAD67 and PV expression has also been reported in various CNS pathologies, such as psychiatric disorders (Reynolds et al. 2004), Alzheimer’s disease (Solodkin et al. 1996), epilepsy (Lau et al. 2000) as well as during cortical microstimulation-induced circuit remodelling (Benali et al. 2008).