brain-derived neurotrophic factor (bdnf) is also a myokine, though bdnf produced by contracting muscle is not released into circulation. rather, bdnf produced in skeletal muscle appears to enhance the oxidation of fat. skeletal muscle activation through exercise also contributes to an increase in bdnf secretion in the brain. a beneficial effect of bdnf on neuronal function has been noted in multiple studies. dr. pedersen writes, "neurotrophins are a family of structurally related growth factors, including brain-derived neurotrophic factor (bdnf), which exert many of their effects on neurons primarily through trk receptor tyrosine kinases. of these, bdnf and its receptor trkb are most widely and abundantly expressed in the brain. however, recent studies show that bdnf is also expressed in non-neurogenic tissues, including skeletal muscle. bdnf has been shown to regulate neuronal development and to modulate synaptic plasticity. bdnf plays a key role in regulating survival, growth and maintenance of neurons, and bdnf has a bearing on learning and memory. however, bdnf has also been identified as a key component of the hypothalamic pathway that controls body mass and energy homeostasis.