In Certain FM and CF-FM Bats

調頻蝙蝠與常頻調頻蝙蝠小腦神經元對聲刺激的反應(上標 +)

任晃蓀(Philip Hung-sun Jen) ； 鐮田勉(Tsutomu Kamada) ； 孫心德(Xin-de Sun) ； 施烈格(Peter Schlegel) ； 法特爾(Marianne Vater) ； 哈泥施費格(Gunter Harnischfeger) ； 魯伯沙門(Rudolf Rubsamen)

《The Chinese Journal of Physiology》 27卷1期 (1984/06) Pp. 1-26

摘要

本實驗係探討兩種調頻蝙蝠(Myotis lucifugus,Eptesicus fuscus)及兩種長頻調頻蝙蝠(Pteronotus Parnellii，Pteronotus parnellii rubiginosus)的小腦聽神經元對聲刺激反應的電生理特性。實驗結果顯示，最佳頻率介于60及63千赫之間的常頻調頻蝙蝠小腦神經元對聲刺激的音調非常峭急。這些神經元在聲刺激結束時，也發放動作電位（圖5E）,此種現象則不見於調頻蝙蝠的小腦種經元。小腦神經元的閥曲線可分為狹窄、寬濶及不規則三種（圖6），狹窄及寬濶型的閥曲線均呈三角形，但不規則閥曲線則含有兩個以上的靈敏峰。以常頻聲刺激所側得小腦聽神經元的聲強與動作電位發放數率的關係函數可分為單調型與非單調型兩種，以不同型的聲刺激測量Eptesicus fuscus的小腦神經元的反應結果顯示絕大部份的小腦神經元對4毫秒的下降調頻聲刺激最為敏惑，這些小腦神經元的最大方向靈敏度為蝙蝠的正前方或在其左右l0~30。兩種不同蝙蝠小腦聽神經元的音調分佈圖與各種蝙蝠的方向定位聲的聲能量譜非常類似，本實驗結果顯示蝙蝠小腦的聽神經元保持了經由其聽覺系統所處理過的具有生物意義的信息。

並列摘要

Jen, P. H., T. Kamada, X. Sun, P. Schlegel, M. Vater, G. Harnischfegar and R. Rubsamen: Responses of cerebellar neurons to acoustic stimuli in certain FM and CF-FM bats. Chinese J. Physiol. 27(1):1-26, 1984. To study the signal processing on the cerebellum of echolocating bats, electrophysiological properties of cerebellar auditory units of two FM bats, (Myotis. lucifugus and Eptesicus fuscus) and two CF-FM bats, (Pteronotus parnellii parnellii and Pteronotus parnellii rubiginosus) were investigated by recording responses of single units to acoustic stimuli. Cerebellar units of CF-FM bats with BFs between 60 and 63 kHz were sharply tuned. These units also showed an off response upon cessation of the stimulus (Fig.5E). Off responses were not observed from the cerebellar units of FM bats. Threshold curves of isolated units are narrow, broad, or irregular (Fig.6). Narrow and broad threshold curves are all simple triangular shapes, but each of the irregular threshold curves consists of at least two peaks of sensitivity, Intensity-rate functions of cerebellar auditory units measured with pure tone pulses were either monotonic or non-monotonic(Fig.7). A study of the responses of cerebellar units of Eptesicus fuscus to different acoustic stimuli shows that cerebellar units were generally most sensitive to a 4 msec downward sweep FM stimulus. They were also most sensitive to a stimulus delivered in front of the animal or within 10-30° lateral Species-specific histograms of the frequency representation are similar to the power spectrum of a bat’s orientation signals. These data suggest that the auditory units of a bat’s cerebellum preserve the processing of biologically significant signals that occurs in the auditory system.

並列關鍵字

bats ； cerebellum ； auditory neurons ； directional sensitivity