Development of acoustically evoked and spontaneous pre- and postsynaptic discharge activity in the anteroventral cochlear nucleus (AVCN) and in the medial nucleus of the trapezoid body (MNTB): An melectrophysiological in vivo study in mice and Mongolian g

将在出生后第6 - 30天在小鼠和蒙古沙鼠的上行听觉系统的二级神经元（AVCN）和三级神经元（MNTB）中进行细胞外电生理体内记录。这一时期包括听觉诱发信号处理开始之前的时间，直到（几乎）中枢听觉信号的生理成熟。在两个靶核中，记录将使得能够区分相应主神经元的突触前电活动和突触后活动（EPSP和/或动作电位）。这些数据将允许仔细检查出生后发育的（i）自发和（ii）刺激诱发的放电活动，（iii）突触传递的可靠性的变化和（iv）在体内的突触延迟。选择小鼠作为实验动物是因为在未来的实验中可能使用基因操作的标本，而沙鼠特别适合，因为它们对低频有明显的敏感性，这为精确分析信号处理的时间方面（例如锁相）提供了机会。在传入纤维（即听觉神经纤维、梯形体纤维）电刺激后，将通过多电极阵列（MEA）对相应神经元进行急性脑干切片的额外记录。该制剂允许选择性地药理学操纵突触前和突触后放电活动。这种细胞外记录技术将被应用于连接的结果，从在体内的数据，以获得大量的不同的实验数据，膜片钳记录。

Extracellular electrophysiological in vivo recordings will be performed in second order neurons (AVCN) and third order neurons (MNTB) of the ascending auditory system in mice and Mongolian gerbils between postnatal days 6 and 30. This period includes the time before the onset of acoustically evoked signal processing up to (almost) physiological maturity in central auditory signaling. In both target nuclei, the recordings will enable a differentiation between the presynaptic electrical activity and the postsynaptic activity (EPSP and/or action potential) of the respective principal neurons. The data will allow to scrutinize the postnatal development of (i) spontaneous and (ii) stimulus evoked discharge activity, (iii) changes in the reliability of synaptic transmission and (iv) in the synaptic delay in vivo. Mice were chosen as an experimental animal because of the potential use of genetically manipulated specimen in future experiments, and gerbils are specifically suited because of their distinctly developed sensitivity for low frequencies, which provides the opportunity for precise analysis of temporal aspects of signal processing (e.g. phase locking). Additional recordings on acute brainstem slices by means of multi-electrode arrays (MEA) will be performed from the respective neurons after electrical stimulation of the afferent fibers (i.e. auditory nerve fibers, fibers of the trapezoid body). This preparation allows selective pharmacological manipulations of pre- and postsynaptic discharge activity. This extracellular recording technique will be applied to link the results from the in vivo data to the large body of diverse experimental data obtained by patch clamp recordings.