, 2012). We can only speculate screening assay how big a role such dramatic variation will play in future pharmacogenomics findings—but it will probably be large. Genetics is not the whole answer but offers a solid starting point. Further knowledge of the basic disease processes at the cellular and molecular level will be required to discover ideal, curative treatments for most patients with neuropsychiatric disorders, but much could be achieved by personalizing the existing pharmacopeia. Personalized

medicine will bring new insights, more treatment options, and better outcomes to what psychiatrists have always strived for—caring for each patient as an individual. This work was supported by the NIMH Intramural Research Program. We thank Gonzalo Laje for helpful comments. “
“For decades, it has been recognized that axon regeneration is the only way to restore function after severe spinal cord injuries (SCI) that interrupt the long tracts that mediate motor and sensory function. Indeed, SCI and axon regeneration are so linked in the minds of scientists

and the lay public that enabling regeneration after SCI Fasudil nmr is iconic. Achieving axonal regeneration with recovery of function would truly be an extraordinary achievement. Despite progress, measured both as a gain in understanding of the molecular-, cellular-, and systems-level underpinnings of axonal growth, and in the number of investigators studying the topic, success has not yet been achieved. Indeed, progress in the field is nonlinear, with many instances of premature celebration of success, mistargeting, sidesteps, and occasional episodes of withdrawal. The during reasons for this are numerous, ranging from

lack of clarity in use of terminology related to axonal growth and limitations of experimental methods to a lack of rigor in interpretation. This primer aims to provide a framework for the study of axonal growth after spinal cord injury. We focus on SCI not only because it is iconic, but also because it exemplifies all of the issues that plague studies of axon regeneration in any CNS region with mixed white and gray matter. We begin by addressing the meaning of different terms used to describe growth after injury, especially the terms “regeneration” and “sprouting.” Inconsistent use of these terms in the scientific literature creates ambiguity or frank error in interpreting experimental findings. We then review several model systems for studying axonal growth after spinal cord injury, highlighting the advantages and limitations of several models. Finally, we will discuss the tools available to study axonal regeneration and how these might best be applied to reach new levels of insight that will point the way to strategies for improving outcomes after spinal cord injury.