Replicable in vivo physiological and behavioral phenotypes of the Shank3B null mutant mouse model of autism

• Published in: Molecular autism 2017-06, Vol.8 (1), p.26-26, Article 26
• Main Authors: Dhamne, Sameer C, Silverman, Jill L, Super, Chloe E, Lammers, Stephen H T, Hameed, Mustafa Q, Modi, Meera E, Copping, Nycole A, Pride, Michael C, Smith, Daniel G, Rotenberg, Alexander, Crawley, Jacqueline N, Sahin, Mustafa
• Format: Article
• Language: English
• Subjects: Animals; Anxiety; Anxiety - diagnosis; Anxiety - genetics; Anxiety - physiopathology; Autism; Autistic Disorder - diagnosis; Autistic Disorder - genetics; Autistic Disorder - physiopathology; Behavior; Behavior, Animal; Biomarkers; Biomarkers - analysis; Colleges & universities; Convulsants - administration & dosage; Disease Models, Animal; Electroencephalography; Female; Females; Gamma oscillations; Genetic aspects; Grooming; Humans; Interpersonal Relations; Laboratory animals; Male; Maze Learning; Memory; Mice; Mice, Knockout; Mutation; Nerve Tissue Proteins - deficiency; Nerve Tissue Proteins - genetics; Neurodevelopmental disorders; Pentylenetetrazol; Pentylenetetrazole - administration & dosage; Psychological aspects; Repetitive behavior; Reproducibility of Results; Rodents; Seizures - chemically induced; Seizures - genetics; Seizures - physiopathology; Shank3B; Social aspects; Social behavior; Synapses; Telemetry
• ISSN: 2040-2392; 2040-2392
• DOI: 10.1186/s13229-017-0142-z

Autism spectrum disorder (ASD) is a clinically and biologically heterogeneous condition characterized by social, repetitive, and sensory behavioral abnormalities. No treatments are approved for the core diagnostic symptoms of ASD. To enable the earliest stages of therapeutic discovery and development for ASD, robust and reproducible behavioral phenotypes and biological markers are essential to establish in preclinical animal models. The goal of this study was to identify electroencephalographic (EEG) and behavioral phenotypes that are replicable between independent cohorts in a mouse model of ASD. The larger goal of our strategy is to empower the preclinical biomedical ASD research field by generating robust and reproducible behavioral and physiological phenotypes in animal models of ASD, for the characterization of mechanistic underpinnings of ASD-relevant phenotypes, and to ensure reliability for the discovery of novel therapeutics. Genetic disruption of the gene, a scaffolding protein involved in the stability of the postsynaptic density in excitatory synapses, is thought to be responsible for a relatively large number of cases of ASD. Therefore, we have thoroughly characterized the robustness of ASD-relevant behavioral phenotypes in two cohorts, and for the first time quantified translational EEG activity in null mutant mice. In vivo physiology and behavioral assays were conducted in two independently bred and tested full cohorts of null mutant ( KO) and wildtype littermate control (WT) mice. EEG was recorded via wireless implanted telemeters for 7 days of baseline followed by 20 min of recording following pentylenetetrazol (PTZ) challenge. Behaviors relevant to the diagnostic and associated symptoms of ASD were tested on a battery of established behavioral tests. Assays were designed to reproduce and expand on the original behavioral characterization of KO mice. Two or more corroborative tests were conducted within each behavioral domain, including social, repetitive, cognitive, anxiety-related, sensory, and motor categories of assays. Relative to WT mice, KO mice displayed a dramatic resistance to PTZ seizure induction and an enhancement of gamma band oscillatory EEG activity indicative of enhanced inhibitory tone. These findings replicated in two separate cohorts. Behaviorally, mice exhibited repetitive grooming, deficits in aspects of reciprocal social interactions and vocalizations, and reduced open field activity, as well as variable deficits in