We describe an electrical injury method, electroablation, which will contribute to regeneration and inflammation research by providing a simple and versatile method for neurectomy, tissue ablation and inflammation induction. The transparency of zebrafish larvae and availability of fluorescent tags in specific tissues in transgenic fish, combined with the advantages of an electrical injury method (localized and precise tissue damage and modulation of the extent of the damage), will now facilitate in vivo analysis of regeneration and inflammation. Moreover, electroablation can also be applied to adult fish, making it possible to carry out regeneration and inflammation studies in this context.
While other methodologies allow single cell ablation with high precision or even to sever a single axon , our approach allows localized tissue damaged without cell type specificity. We think this can be an advantage rather than a limitation, since nerve and tissue injury generally involve non-specific damage to several cell types. Therefore, we propose electroablation as a relevant model for inducing tissue injury in a way that reflects all of the non-specific tissue damage related events. This aspect is critical for regeneration studies, since it has been reported that tissue regeneration depends on hydrogen peroxide production [12, 41], which is induced by tissue damage but does not occur in response to single cell ablation .
Our laboratory is particularly interested in the regeneration of both the pLL nerve and neuromasts. We believe that electroablation will be of value for the study of the molecular mechanisms and the roles of different cell types involved in regeneration in both models. In spite of the high resistence of nerves and their surrounding tissues, we show successful pLL nerve neurectomy by electroablation, as a cheap and simple alternative to more sophisticated approaches, such as two-photon axotomy . Similarly to previous studies performed by two-photon axotomy on the pLL nerve  we observed Wallerian degeneration of the detached axons after electroablation and, later, pLL nerve regeneration. In addition to pLL nerve regeneration studies, this methodology will allow the study of the mechanisms involved in hair cell re-innervation, as well as the role of inervation on hair cell regeneration in this organ system.
Using electroablation we show, for the first time, the complete ablation and regeneration of a single neuromast. Since electroablation allows single neuromast ablation, we foresee that this method will make it possible to study the mechanisms involved in single neuromast regeneration as well as the role of different cell types, such as interneuromastic cells, Schwann cells, neutrophils and macrophages in this process.
Furthermore, we show that electroablation can be adapted to be used in adult fish, allowing the study of regeneration and inflammation in adult animals. This advantage could be used to investigate the effects of chronic conditions, such as exposure to toxic compounds, on regeneration and inflammation, for example.
Other potential applications of electroablation
In addition to peripheral neurectomy, neuromast ablation, spinal cord injury, inflammation induction and tissue damage in adult fin tissue, we foresee additional applications using this methodology. First, electroablation can be modified for use in regeneration studies as a general strategy for ablation of different tissues. Tissues and organs where electroablation should be feasible include the liver, olfactory rosettes, blood vessels, muscles, eyes, brain, and ganglia. Furthermore, electroablation could be used as a reproducible method for injury to almost any superficial tissue with the aid of the appropriate transgenic fish labeling the tissue of interest. Our method should be of use even in deep tissues with the aid of simple surgery protocols, making it possible to inflict damage in internal organs in adult fish.
Second, since electroablation allows localized tissue damage and modulation of the degree of damage, this approach can be used for inflammation studies. Different methods have been used to induce inflammation in zebrafish, which include techniques involving physical methods, such as manual tail transection  and laser induced wounds , or a genetically induced chronic inflammatory condition . Our approach takes advantage of small microelectrodes and electrical pulses to induce a localized tissue injury that induces immune cell recruitment. Thus, the main advantages of this method for inflammation studies are its robustness and versatility. Since our methodology relies on electrical pulses, it allows different degrees of tissue damage, which can be achieved by means of controlling current intensity, and the number and duration of the pulses applied. This advantage could be used to investigate possible relationships between the extent of tissue damage and the inflammatory response, and furthermore, to study the mechanisms of resolution of inflammation involved in each case.
Furthermore, this approach allows repeated localized tissue damage, a useful approach for the study of the dynamics of immune cells. Since this method can be easily combined with in vivo time lapse imaging of immune cells (Additional file 2) and with cell tracking tools, leukocyte navigation could be studied in an inflammatory context in vivo, knowing exactly where the inflammatory signals will be produced. Thus, questions regarding signal integration, receptor desensitization and immune cell fate after successive inflammatory stimuli, aspects that remain unknown, could be addressed with the aid of this methodology.
Finally, electroablation is a powerful tool for neuroinflammation studies, as it allows nervous system injury or neurectomy as well as inflammation induction. The aforementioned advantages of this approach could be used to investigate the molecular mechanisms of immune system involvement in axon or neural regeneration.