A rapid startle response in larval lampreys.
Electromyography (EMG) and cinematography revealed a rapid, vibration-evoked startle response in intact larval lampreys. Vibratory stimuli produce simultaneous contraction of both sides of the body, and the response is lost after labyrinthectomy. Midbody EMGs exhibit a stimulus-response latency of 26.5 +/- 4.2 ms. Direct stimulation of the otic capsules, using an electrically driven probe applied to a semi-intact preparation, first evokes a volley of giant axon spikes in the spinal cord followed by the bilateral trunk response.
D000818:Animals; D002490:Central Nervous System / Q000502:physiology*; D007758:Ear, Inner / Q000502:physiology*; D004576:Electromyography; D005399:Fishes / Q000502:physiology*; D007798:Lampreys / Q000502:physiology*; D009040:Motion Pictures; D009132:Muscles / Q000502:physiology; D011187:Posture; D011930:Reaction Time / Q000502:physiology; D013216:Reflex, Startle / Q000502:physiology*; D014732:Vibration