ONTOGENY OF AUDITORY SYSTEM STRUCTURE AND FUNCTION

初步研究表明，在没有声学的情况下 刺激大细胞核团(NM)和板层核团的神经元 (Nl)雏鸡同步、有节律地排出 图案。这种自发性、同步性的节奏模式 排泄物只发生在胚胎发育期间 听证。这一系列实验提出了进一步 描述这种自发放电的模式。整体而言 目的是为了更好地理解自发的作用 活动在听觉系统结构发育中的作用 和功能。 自发的单个和多个单元活动的录音将是 由胚胎中的听觉脑干通路制成。第一 实验将确定节律性放电的速度 作为沿色调渐变的位置的函数变化，单位为NM 和NL.先前的研究表明，有两种不同的节奏 的自发活动有时被同时记录下来 来自相同的电极。第二个实验将绘制 这些双重节律的位置。是否存在双重身份的问题 节律反映了大脑两侧的活动情况 通过检查单侧耳蜗术后的影响来确定 节律上的移除。在第三个实验中，问题是 NM和NL的放电节律模式是否反映了 听神经的活动将通过记录 神经中的自发活动。在第四个实验中， NM中单个单元的自发放电模式将为 通过计算区间直方图和 自相关图。在上一次实验中， 自发活动最先发生并影响突触后 功能将通过确定何时单边进行评估 去除耳蜗先引起(14C)2-脱氧-D-脱氧核糖核酸的不对称性 中枢听觉系统的葡萄糖摄取。

Preliminary studies have shown that in the absence of acoustic stimulation, neurons in n. magnocellularis (NM) and n. laminaris (NL) of the chick discharge synchronously and in a rhythmic pattern. This rhythmic pattern of spontaneous, synchronous discharge occurs only during the embryonic development of hearing. The series of experiments propose to further characterize this pattern of spontaneous discharge. The overall objective is to better understand the role that spontaneous activity plays in the development of auditory system structure and function. Recordings of spontaneous single and multiple unit activity will be made from the auditory brainstem pathway in embryos. The first experiment will determine whether the rate of rhythmic discharge varies as a function of position along the tonotopic gradient in NM and NL. Previous studies have shown that two different rhythms of spontaneous activity are sometimes recorded simultaneously from the same electrode. The second experiment will map the location of these dual rhythms. The question of whether dual rhythms reflect activity from the two sides of the brain will be determined by examining the effect of unilateral cochlear removal on the rhythms. In the third experiment, the question of whether the rhythmic pattern of discharge in NM and NL reflects the activity of the auditory nerve will be evaluated by recording the spontaneous activity in the nerve. In the fourth experiment, the pattern of spontaneous discharge of single units in NM will be quantified by computing interval histograms and autocorrelograms. In the last experiment, the time at which spontaneous activity first occurs and influences postsynaptic function will be evaluated by determining when unilateral cochlear removal first causes an asymmetry in (14C)2-deoxy-D- glucose uptake in the central auditory system.