Sutherland D P, Masterton R B, Glendenning K K
Department of Psychology, Florida State University, Tallahassee 32306-1270, USA.
Behav Brain Res. 1998 Dec;97(1-2):1-12. doi: 10.1016/s0166-4328(98)00008-4.
This report is the fourth in a series describing the results of ablation-behavior experiments directed to the ascending output of the cochlear nuclei as it is conducted centrally within the acoustic striae. This fourth report focuses on the unique physiology of the fusiform or 'output' cells of the dorsal cochlear nucleus whose axons course through the dorsal acoustic stria (DAS). Because electrophysiological studies have shown that the cues for sensing the elevation of a sound source would seem to be best analyzed by the dorsal cochlear nucleus and projected centrally via its DAS, we tested normal cats and cats deprived of DAS for their ability to orient to elevated sources of broad-band noise. For behavioral testing, we made use of reflexive or unconditioned orienting responses to elevated sound sources using a similar method to one we have used previously for azimuth testing (Thompson GC, Masterton RB. Brainstem auditory pathways involved in reflexive head orientation to sound. J Neurophysiol 1978;41:1183-1202). The results show that cats deprived of their DAS do indeed have a marked deficit in their ability to orient to an elevated sound source. Further behavioral testing indicated that this deficit is not the secondary result of an attentional or peripheral motor deficit. Although the present results do not prove that the reflexive deficit is strictly auditory in nature, the deficit is notable in that it is the only one yet known to result from a lesion of the dorsal cochlear nucleus or its central projections.
本报告是系列报告中的第四篇，描述了针对耳蜗核上行输出的消融行为实验结果，该实验在听觉纹体内向中枢传导。第四篇报告聚焦于背侧耳蜗核梭形或“输出”细胞的独特生理学特性，其轴突通过背侧听觉纹（DAS）传导。由于电生理研究表明，感知声源高度的线索似乎最好由背侧耳蜗核进行分析，并通过其DAS向中枢投射，因此我们测试了正常猫和去除DAS的猫对宽带噪声声源高度进行定向的能力。在行为测试中，我们利用对声源高度的反射性或非条件性定向反应，采用了一种与我们之前用于方位测试的方法类似的方法（汤普森GC，马斯特顿RB。参与对声音的反射性头部定向的脑干听觉通路。《神经生理学杂志》1978年；41:1183 - 1202）。结果表明，去除DAS的猫在对声源高度进行定向的能力上确实存在明显缺陷。进一步的行为测试表明，这种缺陷不是注意力或外周运动缺陷的继发结果。虽然目前的结果并未证明反射性缺陷本质上严格是听觉性的，但该缺陷值得注意，因为它是已知的唯一由背侧耳蜗核或其中枢投射损伤导致的缺陷。
