PC and prion disease: As the balance of GABA and glutamate heavily involves astrocyte up-take, the Krebs cycle and replenishment of the glutamate pool requires pyruvate carboxylase, an enzyme predominantly expressed in astrocytes [46, 47], this likely suggests that the astrogliosis in FFI prion disease is associated with dysfunctional homeostasis within the glutamate and GABA systems.