BDNF and Huntington disease: Role of BDNF and environmental factors. Although mature BDNF plays a significant neuroprotective role,68 its precursors are believed to cause synaptic depression and cell death.69,70 A study showed that immature oligodendrocytes in the striatum exhibit markedly elevated levels of the BDNF precursor receptors sortilin and p75NTR, which are believed to be closely associated with HD striatal myelin degradation.71