Individuals with autism spectrum disorder (ASD) present a range of distinct behaviors, including difficulties in social interactions and repetitive behaviors. Individuals may also experience seizures, sleep disturbances, altered sensory responses and cognitive challenges. The development of a new high-resolution automated tracking system that can monitor rodent whole-body movements across days and weeks (Marshall et al., Neuron, 2021) provides a critical step in understanding how genetic changes are related to the behavioral characteristics of ASD.
The tracking system designed by SFARI Investigator Bence Ölveczky, Jesse Marshall and colleagues—referred to as CAPTURE (continuous 3D kinematic tracking)—uses three-dimensional motion-capture video technology of animals stably tagged with retro-reflective markers across their bodies combined with an unsupervised deep-learning framework to analyze recorded movements. The study was supported in part by a Pilot Award to Ölveczky to allow monitoring of freely moving behaviors at high spatial and temporal resolution in a rodent model of ASD with Fmr1-knockout rats.
Rodent models have been developed for numerous ASD risk genes, and the broad range of behaviors that rodents exhibit lend themselves to assessing behavioral changes that mimic those seen in ASD. Trained to characterize 140 distinct behavioral and kinematic rodent movement features, CAPTURE boosts resolution to sub-millimeter tracking precision with a low error rate. CAPTURE accurately tracks many natural rodent behaviors — including arousal states, walking, rearing, grooming and scratching — over days and weeks.
The study also demonstrated that CAPTURE detects both known and previously unidentified alterations in behavior, assessed here through the administration of either caffeine or amphetamine. Using a rat model of fragile X syndrome, the most common monogenic form of ASD, the study also found clear instances of repetitive (grooming) behavior.
The study by Ölveczky, Marshall and colleagues provides a proof-in-principle demonstration of the power of the CAPTURE technology for tracking detailed movements in freely behaving rodents. Future studies can utilize CAPTURE to comprehensively track how distinct ASD risk genes affect a wide range of natural rodent behaviors, providing greater insights into how individual genetic changes are related to ASD behavioral presentations.