Spinal Plasticity and Behavior: BDNF-Induced Neuromodulation in Uninjured and Injured Spinal Cord

Figure 3

Proposed mechanism of BDNF-induced synaptic facilitation. Small diameter primary afferents express glutamate and BDNF. ① Under normal conditions, dorsal root stimulation evokes stable glutamatergic synaptic responses in lamina II neurons. ② Increased excitability of primary afferents causes the release of both glutamate and BDNF, which binds to TrkB receptors. Engagement of the TrkB receptors recruits the ③ PLC which can lead to activation of ④ PKC and ⑤ an increase in intracellular calcium . Both PKC and calcium dependent kinases such as CAMK can phosphorylate glutamatergic receptors, thereby increasing their calcium permeability. Consequently, these processes lead to an NMDA-R dependent facilitation of glutamatergic currents. Adapted from data reported in Garraway et al. [89].