Brain-derived neurotrophic factor induces NMDA receptor 1 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 NMDA responses, by a yet unknown mechanism. The phosphorylation of the NMDA subunit 1 following BDNF exposure has been investigated in the neonatal rat spinal cord. Western blotting revealed that BDNF administered to isolated cords for 20 minutes significantly elevated phospho-NR1 levels. Immunohistochemical analysis localised this increase to functionally appropriate regions of the dorsal horn. Pre-incubation with trkB-IgG (BDNF sequestering molecule) abolished this NR1 phosphorylation. We suggest that BDNF modulates synaptic activity within the spinal cord via NR1 phosphorylation.