title: A solid-state ultrasonic activity-recording unit.
mesh_terms: D000669:Amplifiers, Electronic; D000818:Animals; D004581:Electronics; D008722:Methods; D051379:Mice; D009043:Motor Activity; D012666:Semiconductors; D013686:Telemetry; D014159:Transducers; D014465:Ultrasonics / Q000295:instrumentation*