BDNF: a regulator of learning and memory processes with clinical potential

Abstract

Memories are believed to be represented by facilitated synaptic transmission of electrical signals in neuronal networks. The ability to acquire new memories or to change old memory content results from the plastic properties of the brain. Molecular changes in synaptic plasticity of neuronal networks are considered to be the cellular correlates of learning and memory, and the neurotrophin brain-derived neurotropic factor (BDNF) plays an important role in these processes. This neurotrophic factor coordinates a multitude of biological functions. In addition to its role in neuronal plasticity processes, such as long-term potentiation of synaptic transmission, the protein regulates the differentiation of neuronal precursor cells, synaptogenesis, and neuronal survival. Cellular processes like BDNF protein processing, anterograde and retrograde transport, as well as exocytosis and endocytosis of BDNF vesicles are necessary to enable the protein to fulfill its neuroprotective and plasticity-related functions in its target areas. Therefore, deficits in one of these functions, resulting in a reduction or a lack of BDNF supply, can result in dysfunctional or reduced synaptic plasticity in virtually every brain area. Since cognitive processes and mental health require the intact formation and modification of memory traces, a change in BDNF turnover is considered as a contributing factor to a number of neurodegenerative and psychological disorders. This review summarizes the current knowledge regarding the connection between BDNF, its role in synaptic plasticity and its role in brain.