罗非鱼椭圆囊电生理学研究

Electrophysiological observation on sacculus of Tilapia sp

罗非鱼球状囊微音器电位是一个双峰波。峰频与刺激声频成2∶1关系；在20～80Hz电位波形不规则。在300～900Hz电位波呈矩形。实验表明，球状囊不同区域对一定的声频敏感性不一样；延脑－脊髓连结处的诱发电位与球状囊微音器电位相似，但在130Hz电位呈单峰波；罗非鱼可闻频域在20～900Hz，最大敏感声频在130Hz，其相对敏感性为23．01dB；延脑－脊髓连接处诱发电位最大值在63Hz和130Hz，相对敏感性分别为25.36和23．37dB；罗非鱼气鳔与内耳无直接关系，去鳔对其微音电位听力曲线无明显影响。

Using microphonic potentials as a tool,the authors deal with the characters of electrophysiological response of the sacculus of a nonostariophysan fish,Tilapia sp.,to underwater sound stimuli at low frequencies. The results are as follows:1. Microphonic potentials recorded from the sacculus in response to underwater sound stimulation show that the potential is that of the typical microphonic potential of fish,which has two wave Peaks,and the frequency of the potential wave and that of the stimulation has a 2:1 relationship. In this study,the shape of potentials at 20~80Hz is irregular and that at 300~900Hz is rectangle-shaped. Different regions of the sacculus have different response sensitivities to a certain kind of underwater sound.2. Potentials recorded from the cerebellar-medullary junction show a similar feature compared with those from the sacculus. but the POtential from the junction at l3OHz is a single peak,for all of this evoked-potentials should be further studied.3. the result of the microphonic potential curve from the sacculus reveals that Tilapia responds to underwater sound stimulation from 20 to 900 Hz with a maximum sensitive frenquency at 130Hz and its maximum sensitivity is +23. 01 dB (relative). the experiment with cerebellar-medullary junction found that the maximum potentials were at 63 Hz and 130 Hz with maximum sensitivities separately 25. 36 dB and 23. 37 dB(relative).4. Elimination of the swimbladder caused on change in sensitivities at any frequencies,which were in correspondence with the result of anatomy.