BDNF and Alzheimer disease: Furthermore, in the intracerebroventricular (i.c.v) streptozotocin-induced model, claimed by several authors to promote an AD-like phenotype, IN insulin has shown to prevent memory impairment, neuroinflammation and insulin resistance in the hippocampus and cortex (Rajasekar et al., 2017a), as well as promoting restored cerebral blood flow (CBF), decreased ROS and increased BDNF expression (Rajasekar et al., 2017b).