ABSTRACT

Converging evidence from multiple preclinical models suggests that the omega-3 long-chain polyunsaturated fatty acid (LC-PUFA), docosahexaenoic acid (DHA; 22:6n-3), supports nervous system health and function after mechanical damage. Much of this evidence has been acquired from therapeutic approaches attempting to mitigate traumatic brain injury (TBI) or spinal cord injury (SCI) with DHA or other LC-PUFAs. Such findings from multiple approaches are encouraging because only a few compounds have been shown to be clinically effective in treating nervous system damage (e.g., progesterone). Alternatively, it may be that receptor-directed, therapeutic approaches may not be the best way to improve outcomes after nervous system injury because a myriad of cell damage pathways are activated by TBI and SCI. Accordingly, multiple pathways for the protective effects of DHA in TBI and SCI have been proposed, and it may be that pleiotropic approaches (Stein, 2013), such as

9.1 Introduction ..................................................................................................207 9.2 Recommended DHA Intakes ........................................................................208 9.3 Delivery of DHA to the Nervous System .....................................................209 9.4 DHA-Related Mechanisms during Development ......................................... 212

9.4.1 Brain Cell Migration ......................................................................... 213 9.4.2 Neuron Growth and Axon Elongation .............................................. 216 9.4.3 Synaptogenesis .................................................................................. 219 9.4.4 Myelination ....................................................................................... 221

9.5 Maintenance of Brain Health ....................................................................... 223 9.6 Summary and Conclusions ...........................................................................225 References .............................................................................................................. 227

that with DHA, could prove more effective than receptor-directed drugs. However, the recent findings for DHA as a potential therapeutic for TBI and SCI (see MichaelTitus and Priestley, 2014 for review) have not fully accounted for the important roles that DHA plays, as a nutrient for nervous system development and homeostasis. This chapter discusses how the developmental requirements and functions of DHA may provide further explanations for the benefits of DHA after nervous system injury.