• 作者： 任晃蓀; 菅乃武男
• 作者服務機構： 密蘇里州立大學生物系助教授; 密蘇里華盛頓大學生物系正教授
• 中文摘要： In little brown bats (Myotis lucifugus), boththe middle-ear and laryngeal muscles are highlydeveloped. The large middle-ear muscles arepowerful in controlling the transmission of thesound energy across the ossicular chain and thehypertrophied laryngeal muscle is related withthe emission of ultrasonic signals. When thebat emits orientation sounds, action potentialsof middle-ear muscles appear approximately 3milliseconds after those of the laryngeal muscle;this activity of middle-ear muscles attenuates thevocal self-stimulation and improves the perfor-mance of the echolocation system. When anacoustic stimulus is delivered. both types ofmuscles contract; action potentials of laryngealmuscles appear approximately 3 millisecondsafter those of the middle-ear muscles. Theactivity of acoustic laryngeal muscle reflex shayact as a negative feedback loop to stabilize theoperation of the vocalization system. Sincethese two groups of muscles discharge actionpotentials prior to the vocalization as well asduring the acoustic stimulus, both muscles areapparently activated in a coordinated mannernot only by the nerve impulses from thevocalization system, but also by those from theauditory system.
• 英文摘要： --
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