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猫听觉脑干诱发电反应中P_(2a)和P_(2b)波的起源

康健, 魏保龄

中国医科大学听力研究室

摘要

在33例猫将普鲁卡因或海人酸微量注入耳蜗核(CN)和上橄榄复合体(SOC)内,观察ABR的相应改变,以分析P_(2a)和P_(2b)波的来源。猫P_(2a)波的出现率与电极导联有关,颅顶-颈后为90％,颅顶-乳突仅为18％。普普卡因注入CN后,同侧耳短声诱发的ABR仅保留P_(1)波,对侧耳的则无改变。海人酸注入CN后,P_1和P_(2a)存留,P_(2a)不减小反而增大。普鲁卡因注入双侧SOC,可使P_(3)、P_(4)和P_(5)消失。这些结果提示,P_(2a)波主要起源于CN区域内的第一级听觉传入神经元轴突并受第二级神经元负电位的影响,P_(2b)波主要起源于SOC以下的第二级听觉传入神经元,猫的P_(2a)和P_(2a)波与对侧脑干结构无关。

关键词： 听觉脑干诱发电反应; 电位起源; 普鲁卡因效应; 海人酸效应

Origins of P_(2a) and P_(2b) of auditory brainstem responses in the cat

Kang Jian, Wei Baoling

Audiological Laboratory of China Medical University

Abstract

Procaine or kainic acid was microinjected into the cochlear nucleus (CN) and superior olivary complexus (SOC) in 33 cats. Origins of P_(2a) and P_(2b) were investigated through observing effects of these agents on auditory brainstem responses (ABR). Incidence of the appearance of P_(2a) in cats was related to site of the reference electrode. It was 90% in vertex-vs-neck lead, but only 18% in vertex-vsmastoid lead. After injection of procaine into CN, only P_(1) remained in the ipsilateral ABR while the contralateral ABR did not change. After injection of kainic acid into CN, both P_(1) andP_(2a) remained but the amplitude of P_(2a) is increased. P_(3), P_(4) and P_(5) disappeared after bilateral injection of procaine into SOC. These results suggest that P_(2a) is generated mainly from the axon terminals of the primary auditory afferent neurons in the vicinity of CN, and is somewhat modified by a negative potential generated from the second auditory afferent neurons below SOC. Contralateral brainstem structures have no contribution to P_(2a) and P_(2b) in the cat.

Key words: Auditory brainstem response;Origin of potential;Procaine effect;Kainic acid effect

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引用本文：

康健, 魏保龄. 猫听觉脑干诱发电反应中P_(2a)和P_(2b)波的起源[J]. 生理学报 1986; 38 (3): .

Kang Jian, Wei Baoling. Origins of P_(2a) and P_(2b) of auditory brainstem responses in the cat. Acta Physiol Sin 1986; 38 (3): (in Chinese with English abstract).