The ever-expanding volume of original articles creates difficulty for even the most resolute to remain current and to readily assimilate topics outside one’s expertise. Narrative scientific reviews are, therefore, invaluable resources and the Journal is pleased to continue to publish these popular and discerning compilations on a regular basis. By nature, and given the compiler’s particular expertise and viewpoint, narrative reviews highlight and interpret subsets of the literature. In contrast, systematic review and meta-analysis are powerful analytical tools typically used to analyze the effects of a drug or treatment, and offer the most objective evidence regarding efficacy. Such reviews are more familiar in the analysis of clinical data, serving to point out voids and weaknesses in current knowledge and helping to shape further trials. By comparison, such reviews of pre-clinical animal data appear only infrequently and yet these could inform the planning and improve the likelihood of success of future clinical trials, and are clearly an integral part of the drug development process. Pre-clinical systematic reviews also identify where there is a need for further ‘basic’ research, preclude unnecessary study replication, and can contribute to both ‘reduction’ and ‘refinement’ in animal experimentation.
Hopefully, the systematic reviews of pre-clinical data in this issue exemplify these benefits and will encourage their future submission to the Journal. It was our intent that the subjects be wide-ranging: addressing the use of insulin-sensitizing thiazolidinediones in experimental stroke, evaluating whether the re-purposing of histone deacetylase inhibitors represents therapy for acute brain injury in animals, analyzing whether proposed multiple sclerosis therapies have been validated in a pre-clinical model, and determining how well animal models mimic the progressive vascular cognitive impairment observed in humans. As subtext, the reviews highlight the variation in quality of published pre-clinical studies, examine whether critical pieces of data are required to progress to the planning stage of a clinical trial, and include commentary on the appropriateness of the species/age/sex studied and the particular outcome measures selected.
We intend that the periodic inclusion of systematic reviews of animal data in future issues of the Journal of Neurochemistry will appeal to the regular readership, and to clinicians, clinical trials specialists, and those involved in drug development.