摘要目的:探讨双侧声刺激对小鼠下丘单个神经元兴奋性的影响及其潜在的神经回路。方法:给予对侧和同侧声刺激，记录左侧下丘单个神经元特征频率（CF）和最低阈值（MT）。对侧刺激即为右侧单耳声刺激，同侧即为左侧单耳声刺激。设置声刺激频率为CF-对侧，声音幅度为MT-对侧以上10 dB或20 dB，活体全细胞膜片钳技术记录小鼠下丘单个神经元分别对同侧耳、对侧耳声刺激的单侧反应、以及双侧声音同时刺激下的整合反应，比较兴奋性突触后电位（EPSP）的变化。结果:共记录到95个双耳兴奋性神经元，在双耳声刺激下可产生抑制、易化和无整合3种不同效应，其比例分别为37.9%（36/95）、21.1%（20/95）和41.0%（39/95）。在抑制组中，单耳对侧-EPSP和双侧-EPSP波幅分别为（12.37±7.3）mV和（6.54±5.1）mV，差异有统计学意义（ P<0.05）；与对侧-EPSP比较，双侧-EPSP波幅降低21.4%~89.8%，平均降低49.1%。在易化组中，单耳对侧-EPSP和双侧-EPSP波幅分别为（7.32±4.3）mV和（11.77±6.3）mV，差异有统计学意义（ P<0.05）；与对侧-EPSP比较，双侧-EPSP波幅增高20.8%~179%，平均增高56.8%。在无整合组中，对侧-EPSP与双侧-EPSP的波幅差异无统计学意义（ P>0.05）。 结论:双耳整合可能发生在上橄榄核复合体，双侧下丘间的相互作用可能参与了下丘神经元双耳特性的形成。

abstractsObjective:To study the effects of bilateral acoustic stimulation on the excitability of single neurons in the inferior colliculus (IC) in mice, and to explore their potential neural circuits.Methods:The characteristic frequency (CF) and the minimum threshold (MT) of single neuron of left IC were measured under the contralateral and ipsilateral acoustic stimulation respectively. The contralateral stimulation refers to monaural stimuli on the right side, while ipsilateral stimulation refers to that on the left side. The tone frequency and tone amplitude were set at 10 or 20 dB above the contralateral CF and MT, respectively. The excitatory postsynaptic potentials (EPSPs) in response to both unilateral (contralateral and ipsilateral) and bilateral tone stimulation were then recorded using in vivo whole cell patch clamp. The difference between contralateral-EPSPs and bilateral-EPSPs were analyzed. Results:A total of 95 binaural excitatory-excitatory neurons were recorded. There were three types of EPSP induced by bilateral stimulation: suppressive (37.9%, 36/95) , facilitative (21.1%, 20/95) and ineffective (41.0%, 39/95) . Of the suppressive EPSPs, the mean amplitudes corresponding to contralateral and bilateral stimulation were (12.37±7.3) mV and (6.54±5.1) mV respectively, with significantly difference ( P<0.05) ; compared to contralateral EPSP, the amplitude of bilateral EPSP was lower by 21.4% to 89.8% with a mean of 49.1%. Of the facilitative EPSPs, the mean amplitudes corresponding to contralateral and bilateral stimulation were (7.32±4.3) mV and (11.77±6.3) mV respectively, with significantly difference ( P<0.05) ; compared to contralateral EPSP, the amplitude of bilateral EPSP was higher by 20.8% to 179% with a mean of 56.8%. Of the ineffective EPSP, there was no significant difference in the amplitude corresponding to contralateral and bilateral stimulation ( P>0.05) . Conclusions:This study suggests that binaural integration may occur in the superior olivary complex, and bilateral IC interaction may be involved in binaural properties of IC neurons.