Quantitative behavioral models for high-resolution measurement and characterization of tremor in rodents

Tremor is an involuntary, rhythmic movement disorder. Despite its prevalence, the underlying pathophysiology remains poorly understood, and effective treatment options are limited. Animal models are essential in enhancing our understanding of the mechanisms of tremorogenesis and developing new therapeutic interventions. Although tremor is amenable to measurement by automated systems, visual observation is still the most prevalent method for recording tremor in animal studies. This review gives a brief summary of two behavioral methods that enable quantitative measurement of forelimb tremor (the press-while-licking task) and whole-body tremor (the force-plate actometer) in rodents. These methods utilize force transducer and computing technologies to generate high-resolution force-time waveforms for automated detection and characterization of tremor. The focus will be on the sensitive, precise, and quantitative measurement of tremors induced in rodents by low-dose pharmacological agents, brain lesion, physical training, and genetic mutations. The methods reviewed here provide new tools that can facilitate preclinical assessment of treatment strategies for tremor.