Brain-derived neurotrophic factor induces NMDA receptor I phosphorylation in rat spinal cord

The NMDA receptor and the neurotrophin brain-derived neurotrophic factor, BDNF, are involved in central sensitisation and synaptic plasticity in the spinal cord. Recent evidence suggests that BDNF modulates NMIDA responses, by a yet unknown mechanism. The phosphorylation of the NMDA subunit I following BDNF exposure has been investigated in vitro in the neonatal rat spinal cord. Western blotting revealed that BDNF administered to isolated cords for 20 minutes significantly elevated phospho-NRI levels. Immunohistochemical analysis localised this increase to functionally appropriate regions of the dorsal horn. Pre-incubation with trkB-IgG (BDNF sequestering molecule) abolished this NRI phosphorylation. We suggest that BDNF modulates synaptic activity within the spinal cord via NRI phosphorylation.