The Symbiotic Relationship Between Scientific Quality and Animal Research Ethics

Behavioral phenotyping of young Scn1a haploinsufficient mice

Dravet syndrome is a rare, severe, infancy-onset epileptic encephalopathy associated with a high premature mortality. In most patients, Dravet syndrome is caused by a heterozygous loss-of-function mutation in the SCN1A gene encoding the alpha 1 subunit of the sodium channel. Of the variety of SCN1A variants identified in patients with Dravet syndrome, SCN1A missense mutations occur in one-third of cases. The novel Scn1a-A1783V mouse model of Dravet syndrome carries the human Ala1783Val missense variant. Recently, the behavioral phenotype of Scn1a-A1783V haploinsufficient adult mice has been characterized, which may provide a valuable basis for assessment of novel therapeutic approaches. However, there is still limited information on the developmental course of behavioral alterations in the Scn1a-A1783V mouse model, which is of particular relevance for conclusions about face validity and severity classification of the model. Based on reference data from young wildtype mice, we analyzed selected behavioral parameters and fecal corticosterone metabolites in the Scn1a-A1783V mouse model during post-weaning development. Differences in the preference for a sweet saccharin solution between Dravet mice and wildtype mice were observed once mice reached sexual maturity. Nest building behavior was already influenced by the Scn1a genotype during prepubescence. Sexually mature Dravet mice showed a significantly reduced burrowing performance as compared to their wildtype littermates. In the open-field test, pronounced hyperactivity and increased thigmotactic behavior were evident in prepubescent and sexually mature Dravet mice. Analysis of Irwin scores revealed several genotype-dependent changes in handling-associated parameters during the course of adolescence. The information obtained provides insight into the age-dependence of behavioral patterns in the novel Scn1a-A1783V mouse model of Dravet syndrome. In addition, the dataset confirms the suitability of the applied behavioral composite measure scheme for evidence-based assessment of cumulative severity in genetic mouse lines.

Fit for Purpose Assessment: A New Direction for IACUCs

The organization and function of the institutional animal care and use committee (IACUC) is the key component of government regulation and oversight of necessary scientific research using live animals and of AAALAC - International accreditation of animal care and use programs in the United States. The regulations, roles, and responsibilities of IACUCs have evolved since their inception 35 years ago from a limited focus on animal welfare and specific animal procedures to embracing scientific quality, data reproducibility and translation, and animal welfare as inextricably interdependent and critical components of generation of new scientific knowledge and medical treatments. A current challenge for IACUCs is in evaluating whether benefits to be derived (eg, new knowledge or treatments) justify any unavoidable pain, stress, or injury associated with proposed research protocols, because the former are long-term and at best speculative outcomes, whereas the latter are immediate and tangible for the study animals. Scientific consensus is that research most likely to generate significant new knowledge and medical treatments is that conducted to high scientific, technical, and quality standards and reported with full transparency to facilitate reproducibility. As an alternative to current benefits evaluations included in risk benefit and harm benefit constructs, the authors propose that IACUCs assess the proposed research for scientific quality and alignment of study elements with the study purpose (e.g., Fit for Purpose [FfP]), including justifications for study design components, selection of primary endpoints and technologies, rationale for data and statistical analyses, and research communication plans. Fit for Purpose endpoints are objective, immediate, and impactful as are the potential risks for study animals, and at the same time they are the best predictors for achievement of longer-term benefits. We propose that IACUCs and any revision of The ILAR Guide consider FfP concepts in place of traditional benefits assessment to accelerate the generation of new knowledge and treatments benefiting medical and veterinary patients and the environment through better science and animal welfare rather than to continue to rely on speculative future outcomes.