Dietary intervention with DHA and curcumin enhance spinal cord sensory motor learning
Given that the spinal cord is capable of learning sensorimotor tasks and that dietary interventions can influence learning involving supraspinal centers, we asked whether the presence of omega-3 fatty acid docosahexaenoic acid (DHA) and the curry spice curcumin (Cur) could affect spinal cord learning in adult spinal mice. Using Paw Withdrawal instrumental learning paradigm (PaWL) to assess spinal learning we observed that mice fed a diet containing DHA/Cur performed better in the spinal learning paradigm than mice fed a diet deficient in DHA/Cur. Previous studies in the cortex have demonstrated that both DHA and curcumin elevate the expression of brain derived neurotrophic factor (BDNF) and plays a major role in learning and neural plasticity. Here we examined the effect of DHA and curcumin on the Paw Withdrawal learning. The enhanced performance was accompanied by increases in mRNA of molecular markers of learning, i.e., BDNF, cyclic AMP response element-binding protein (CREB), Calcium/Calmodulin Kinase II (CaMKII), and syntaxin 3. Sequestering BDNF with TrkB IgG in the lumbar spinal cord of DHA/Cur fed mice showed significant decrease in spinal learning, and levels of mRNA of BDNF, CaMKII, CREB and syntaxin 3. These results emphasize the capacity of select dietary factors to foster spinal cord learning and suggest the BDNF pathway may be a key mediator of spinal plasticity. Given the non-invasiveness and safety of the modulation of diet, this intervention should be considered in light of their potential to enhance relearning of sensorimotor tasks during rehabilitative training paradigms after spinal cord injury.