BDNF and viral encephalitis: Microglial BDNF was first shown in microglia cultures [57, 58] and soon confirmed in different regions of the CNS during the course of various neurological disorders, such as viral encephalitis [59], traumatic injury [60, 61], ischemia [62], multiple sclerosis [63], Parkinson's disease [64], neuropathic pain [27], and spasticity [21].