BDNF and Cognitive impairment: On the other hands, BDNF has been implicated in cognitive function, because it regulates synaptic plasticity [43] and animals with deletions of BDNF gene in brain areas that include hippocampus show deficits in synaptic plasticity [44] and cognitive impairments [45], [46], whereas animals with increased expression of BDNF show better performance in cognitive tasks [47].