‘Evorego’: Studying Regeneration to Understand Evolution, the Case of the Serotonergic System

their serotonergic system aft er injury in the central nervous system (CNS), I would like to introduce the concept of ‘evorego’. In this case, ‘evorego’ refers to the idea of how we could also try to understand evolution by studying the diff erences and similarities in the regenerative ability between extant species. In mammals, including humans, injury to the adult CNS usually causes an irreversible loss of function because of the inability of the mature CNS to regenerate. One of the main causes for the absence of recovery is the inability of injured axons to regenerate and reconnect with their appropriate targets. By contrast, teleost fi shes and lampreys are able to regain functionality aft er injury in the mature CNS. For example, both zebrafi sh and lampreys are able to recover locomotion that appears normal aft er a complete spinal cord transection [Becker and Becker, 2008; Barreiro-Iglesias and Rodicio, 2011]. Recent studies have shown that serotonergic neurons have an impressive regenerative ability aft er spinal cord injury in both zebrafi sh [Kuscha et al., 2011] and lampreys [Cornide-Petronio et al., 2011]. Using a double labeling tract-tracing tech‘Evodevo’ is an acronym from the words ‘evolution and development’ that is used to name the fi eld of life sciences focused on the study of diff erences and similarities in the developmental process of extant species with the aim of understanding how they have evolved from common ancestors. Th e ‘evodevo’ research fi eld has expanded greatly over the last century thanks to an increase in the number of research groups focusing their eff orts in this discipline and the appearance of science journals specifi cally devoted to publishing new advances in the fi eld (e.g. Evolution and Development ) or journals from a variety of disciplines that publish a considerable percentage of studies that use the ‘evodevo’ approach (e.g. Brain, Behavior and Evolution ). ‘Evodevo’ researchers use a comparative approach to study a specifi c developmental process in diff erent but related species to understand the evolutionary process and try to identify primitive and derived characters, homologies, parallelisms or phenomena of convergent evolution. Here, using as an example recent data [CornidePetronio et al., 2011; Hawthorne et al., 2011; Kuscha et al., 2011] on the ability of diff erent vertebrate species to regenerate Published online: December 6, 2011