BDNF is a neurotrophin known to play an essential role in learning and memory by regulating synaptic transmission (excitatory and inhibitory) and activity-dependent plasticity and inducing long-term potentiation in the hippocampus.26,27 As a result, underexpression or overexpression of BDNF can negatively affect learning and memory,26,27 and numerous studies now seek to identify ways in which to alter BDNF expression (e.g. exercise, diet, supplements, transcranial magnetic stimulation) in an attempt to treat memory deficits associated with aging and neurodegenerative diseases.26 The gene discussed is BDNF; the disease is neurodegenerative disease.