刺激呈现率影响小鼠下丘神经元声反应特性  

Presentation rate of stimulation affected the sound response properties of the mouse inferior colliculus neurons

作　　者：吴飞健[1] 刘双喜[1] 陈其才[1] Bibikov N.G. 

机构地区：[1]华中师范大学生命科学学院,武汉430079 [2]俄罗斯联邦科学中心Andreyev声学研究所,莫斯科117036

出　　处：《华中师范大学学报（自然科学版）》2005年第4期525-529,共5页Journal of Central China Normal University：Natural Sciences

基　　金：国家自然科学基金项目(30470564);湖北省自然科学基金项目(2004ABA180);国家自然科学基金中俄国际合作项目(30211120640)

摘　　要：自由声场条件下,以强度为特征频率阈上5 dB SPL、时程为40 ms的短纯音为声刺激,记录了小鼠下丘神经元对不同呈现率(0.5～20 Hz)的声刺激反应.结果显示,随呈现率的增高,绝大多数神经元(87.3%,103/118)的冲动发放数单调下降,少数(12.7%,15/118)神经元的冲动发放数呈非单调变化,冲动发放数与刺激呈现率之间有显著相关性.即使在低范围内改变呈现率也能显著影响多数神经元的声反应特性,其临界呈现率及最大呈现率低于3.3 Hz的神经元分别超过70% (75.4%,89/118)和40% (44.9%,53/118).此外,提高刺激呈现率,部分神经元(17.8%,21/118)的发放模式发生改变,主要是由紧张型或相位爆发型向相位型转变.可见,下丘神经元声反应特性与声刺激呈现率密切相关.To study the effect of stimulus presentation rate on the sound response properties of mouse inferior colliculus （IC） neurons, the tones with duration of 40 ms at characteristic frequency （CF） of recorded neurons were presented to Nembutal anesthet- ic mice （Mus musculus, Km） at different rates （PR, ranged from 0. 5-20 Hz） under free field stimulation conditions. The stimulus intensities were relative to 5 dB above minimum threshold （MT）. The post-stimuli-time histograms （PSTHs） of 118 neurons were recorded. The results showed that firing rate of the majority of neurons （87.3G, 103/118） monotonically decreased with the PR increasing, whereas in a smaller fraction of neurons （12.7G, 15/118） it non-monotonically varied. There was significant correlation between the firing rate and the PR （P〈0.01）. The sound response properties of most recorded neurons could be dramatically influenced by changing the PR even in the low PR range （〈3.3 Hz）. The total number of neurons with the critical presentation rate （CPR,〈3.3 Hz） and the maximal presentation rate （MPR, 〈 3.3 Hz） were more than 70% （75.4%, 89/118） and 40G （44.9%, 53/148）, respectively. Moreover, the discharge patterns in part of neurons （17.8%, 21/118） were transformed with the PR alteration. Many neurons with tonic responder（T） and phasic-burst responder （PB） were changed into the phasic responder（P）. The present data demonstrate that the sound response properties of IC neurons were closely correlated to the PR of acoustic stimulation.

关 键 词：下丘神经元 刺激呈现率 小鼠 

分 类 号：Q429.8[生物学—神经生物学]