BDNF and neurodegenerative disease: This observation may provide an answer to a clinical dilemma, namely, what drug should be used as anaesthetic or sedative in situations where the m-BDNF/TrkB system is under pressure to protect normal neural functions against the deleterious effects of stressors such as trauma, surgery, inflammation, hypoxia, and pre-existing neurodegenerative disease (Alzheimer’s)?