ONTOGENY OF AUDITORY SYSTEM STRUCTURE AND FUNCTION

初步研究表明，在没有声学的情况下， 刺激，神经元。 magnocellularis（NM）和n.板层 (NL)同时有节奏地分泌 格局 这种自发同步的节奏模式 放电只发生在胚胎发育期间， 听证会 这一系列实验表明， 描述这种自发放电的模式。 整体 目的是为了更好地理解自发的作用， 活动在听觉系统结构的发展中起作用 和功能 将记录自发的单个和多个单位活动 由胚胎的听觉脑干通路产生。 第一 实验将确定节律放电的速率 作为位置的函数沿着NM中的音调梯度变化 和NL。 先前的研究表明两种不同的节奏 有时会同时记录到 来自同一个电极。 第二个实验将绘制 这些双重节奏的位置。 关于是否双重的问题 反映大脑两侧活动的节律将 通过检查单侧耳蜗 在节奏上移动。 在第三个实验中， NM和NL的放电节律模式是否反映了 听觉神经的活动将通过记录 神经的自发活动 在第四个实验中， NM中单个单位的自发放电模式将是 通过计算区间直方图进行量化， 自相关图 在最后一个实验中， 自发活动首先发生并影响突触后 将通过确定何时单侧 耳蜗切除首先导致（14 C）2-脱氧-D- 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.