BDNF and memory impairment: It is confirmed that HDAC2 up‐regulation will impair BDNF‐TrkB signalling pathway and results in cognitive impairments induced by isoflurane.54 Our previous study also verified the role of BDNF‐TrkB signalling pathway in the cognitive deficits induced by propofol during late pregnant stage.5 Whether BDNF‐TrkB signalling pathway involves in the learning and memory impairments induced by maternal propofol anaesthesia needs to be explored in future study.