Measurement of acoustic startle response in mice

Apparatus for measurement of acoustic startle response in mice is described. The technique utilizes a spring suspended lever, commercially available strain-gauge transducer, and polygraph. Individual startle responses are recorded as upward (flexion) and downward (extension) pen deflections, the force of either component being linearly related to the amplitude of the vertical pen deflections. The apparatus, with minor modifications, may be used to measure startle responses in larger rodents.