Bremen Peter, Poganiatz Iris, von Campenhausen Mark, Wagner Hermann
Institute of Biology II, RWTH Aachen, Aachen, Germany.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2007 Jan;193(1):99-112. doi: 10.1007/s00359-006-0172-z. Epub 2006 Sep 26.
Standard electrophysiology and virtual auditory stimuli were used to investigate the influence of interaural time difference on the azimuthal tuning of neurons in the core and the lateral shell of the central nucleus of the inferior colliculus of the barn owl. The responses of the neurons to virtual azimuthal stimuli depended in a periodic way on azimuth. Fixation of the interaural time difference, while leaving all other spatial cues unchanged, caused a loss of periodicity and a broadening of azimuthal tuning. This effect was studied in more detail in neurons of the core. The azimuthal range tested and the frequency selectivity of the neurons were additional parameters influencing the changes induced by fixating the interaural time difference. The addition of an interaural time difference to the virtual stimuli resulted in a shift of the tuning curves that correlated with the interaural time difference added. In this condition, tuning strength did not change. These results suggest that interaural time difference is an important determinant of azimuthal tuning in all neurons of the core and lateral shell of the central nucleus of the inferior colliculus, and is the only determinant in many of the neurons from the core.
采用标准电生理学和虚拟听觉刺激来研究双耳时间差对仓鸮下丘中央核团核心区和外侧壳层神经元方位调谐的影响。神经元对虚拟方位刺激的反应以周期性方式依赖于方位。固定双耳时间差，同时保持所有其他空间线索不变，会导致周期性丧失和方位调谐变宽。在核心区的神经元中对这种效应进行了更详细的研究。测试的方位范围和神经元的频率选择性是影响固定双耳时间差所引起变化的其他参数。在虚拟刺激中添加双耳时间差会导致调谐曲线发生与所添加的双耳时间差相关的偏移。在这种情况下，调谐强度不变。这些结果表明，双耳时间差是下丘中央核团核心区和外侧壳层所有神经元方位调谐的重要决定因素，并且是核心区许多神经元方位调谐的唯一决定因素。
