Reproducibility via coordinated standardization: a multi-center study in a Shank2 genetic rat model for Autism Spectrum Disorders

Abstract

Inconsistent findings between laboratories are hampering scientific progress and are of increasing public concern. Differences in laboratory environment is a known factor contributing to poor reproducibility of findings between research sites, and well-controlled multisite efforts are an important next step to identify the relevant factors needed to reduce variation in study outcome between laboratories. Through harmonization of apparatus, test protocol, and aligned and non-aligned environmental variables, the present study shows that behavioral pharmacological responses in Shank2 knockout (KO) rats, a model of synaptic dysfunction relevant to autism spectrum disorders, were highly replicable across three research centers. All three sites reliably observed a hyperactive and repetitive behavioral phenotype in KO rats compared to their wild-type littermates as well as a dose-dependent phenotype attenuation following acute injections of a selective mGluR1 antagonist. These results show that reproducibility in preclinical studies can be obtained and emphasizes the need for high quality and rigorous methodologies in scientific research. Considering the observed external validity, the present study also suggests mGluR1 as potential target for the treatment of autism spectrum disorders.

Figure 1

(A–C)Absolute values for walking (A), rearing (B), and circling (C) across the three sites from automated scoring analysis (full 30’ session). (D–F) Normalized values relative to the vehicle for walking (D), rearing (E), and circling (F) across the three sites. The averaged site values for the respective dose levels (depicted in D–F) are shown in (G–I). Pooled data from the three sites under vehicle condition for both genotypes for walking (J), rearing (K), and circling (L) behavior. All values are expressed as mean ± S.E.M. *Statistically significant differences (p < 0.05), ^#Points out trend (p = 0.06).

Figure 2

Absolute values across treatments for walking time (A–C), rearing frequency (D–F), and circling frequency (G–I) for the second 10-minute bin of the automated (triangles) and manual scored (circles) data, comparing the KO (black shapes) and WT (white shapes) rats. All data points express the mean ± S.E.M.