This study showed that the mt and sharpness of frequency tuning curves increased as the sound direction changed from contralateral to ipsilateral azimuthal angles . it suggests that sound direction effect on frequency tuning may be through the complex interplay between the excitatory and inhibitory inputs . the application of gaba ( a ) antagonist , bicuculline , lowered all mts but the application did not abolish direction - dependent variation in mt 听皮层的抑制性影响使大多数神经元在蝙蝠最敏感的声源方位c - 40的频率分辨能力明显提高，同时使c - 40和i - 40的最低阈值的差别进一步增大，提高了信噪比，提高下丘听神经元对声源方位和最佳频率的分辨能力。
The results indicate : ( 1 ) there are interactions between the neurons in iso - frequency laminas and hetero - frequency laminas , and the mutual inhibition is predominant ; ( 2 ) the mutual inhibition of the inferior collicular neurons can increase the frequency selectivity , and play an important role in modifying the discharge features of the neurons 上述结果表明： （ ）下丘神经元声信号处理过程中，位于同频层内及非同频层的神经元之间存在相互作用，该作用以相对抑制为主； （ 2 ） ic神经元之间的相互抑制作用可增强神经元的频率选择性，并对神经元的发放特征有重要的修饰作用。
Corticofugal modulation of frequency tuning of inferior collicular neurons in big brown bat , eptesicus fuse us chinese science bulletin , 2000 in order to explore the possible mechanism of corticofugal modulation of excitatory frequency tuning curves ( eftcs ) of midbrain neurons , we examine the change of sharpness , frequency - intensity response area , minimum threshold of both eftcs and inhibitory frequency tuning curves ( iftcs ) of inferior coliicular neurons during corticofugal modulation using two - tone inhibition paradigm and micro - electrical stimulation technique 第二章大棕幅听皮层对中脑下丘听神经元频率调谐曲线的调制科学通报， 2000用双声刺激的方法和电刺激技术，进一步研究了在激活听皮层前后下丘听神经元兴奋性和抑制性频率调谐曲线的锐度、频率强度反应区域、最低阈值的协同变化
In order to study the effect of weak noise on the sound signal extraction of mouse ( mus musculus km ) inferior collicular ( ic ) neurons from environment , we examined the change in frequency tuning of neuron induced by a weak noise relative to 5 db below minimum threshold ( remt - 5 db ) of tone . 12 healthy adult mice ( 20 - 25 g , b . wt . ) 本实验旨在探讨弱噪声对小鼠( musmusculuskm )中脑下丘( inferiorcolliculusic )神经元声信号提取的影响及其神经机制，我们选用相当于纯音阈下5db的白噪声( whitenoise ) ，比较加入噪声前后神经元频率调谐曲线的变化和注射-氨基丁酸( - aminobutyricacid ， gaba )能受体拮抗剂荷包牡丹碱( bicuculline ， bic )后对该变化的影响。
