Ponton C W, Moore J K, Eggermont J J
Department of Electrophysiology, House Ear Instutute, Los Angeles, California, USA.
Ear Hear. 1996 Oct;17(5):402-10. doi: 10.1097/00003446-199610000-00006.
In attempting to correlate developmental anatomical data with electrophysiological data on maturation of the auditory brain stem response (ABR), a model of ABR generation was necessary to match neuroanatomical structures to ABR components. This model has been developed by reviewing quantitative studies of human brain stem nuclei, results of intrasurgical recordings, studies of correlation of pathology with ABR waveform alterations, and findings from direct stimulation of the human cochlear nuclei through a brain stem implant device. Based on this material, it was assumed that waves I and II are generated peripherally in the auditory nerve and that waves III, IV, and V are generated centrally, i.e., by brain stem structures. It was further assumed that wave III is generated by axons emerging from the cochlear nuclei in the ventral acoustic stria and that waves IV and V reflect activity in parallel subpopulations of these ascending axons at a higher brain stem level. Beyond the cochlear nucleus, the largest component of the brain stem auditory pathway consists of axons projecting without interruption from the cochlear nuclei to the contralateral lateral lemniscus and inferior colliculus. In the proposed model of ABR generation, the III-IV interwave interval is assumed to reflect only axonal conduction in this asynaptic pathway. Electrophysiological data from infants indicate that the III-IV interwave interval becomes adult-like by the time of term birth. The second largest component of the brain stem auditory pathway is the bilateral projection through the medial olivary nucleus. The model assumes that activity in this monosynaptic pathway, consisting of axonal conduction time plus one synaptic delay, is reflected in the III-V interwave interval. If both of the preceding assumptions are true, the IV-V interwave interval represents the difference between the two pathways, i.e., the time of transmission across one synapse. The electrophysiological ABR data indicates that the IV-V interval does not mature until one year of age. It is also possible to apply this model to the peripherally generated portion of the ABR. The I-II interwave interval, assumed to solely represent conduction in VIIIth nerve axons, is adult-like before the time of term birth. The II-III interval, presumed to contain a synapse in the cochlear nuclear complex, does not reach an adult level until between 1 and 2 yr postnatal age.
为了将发育解剖学数据与听觉脑干反应（ABR）成熟的电生理数据相关联，需要一个ABR产生模型，以便将神经解剖结构与ABR成分相匹配。该模型是通过回顾人类脑干核的定量研究、手术中记录的结果、病理学与ABR波形改变的相关性研究以及通过脑干植入装置直接刺激人类耳蜗核的研究而建立的。基于这些资料，假定波I和波II在听神经外周产生，而波III、波IV和波V在中枢产生，即由脑干结构产生。进一步假定波III由腹侧听纹中从耳蜗核发出的轴突产生，而波IV和波V反映这些上行轴突在更高脑干水平的平行亚群中的活动。除耳蜗核外，脑干听觉通路的最大组成部分是从耳蜗核不间断地投射到对侧外侧丘系和下丘的轴突。在提出的ABR产生模型中，假定III-IV波间期仅反映这条无突触通路中的轴突传导。婴儿的电生理数据表明，III-IV波间期在足月出生时就已接近成人水平。脑干听觉通路的第二大组成部分是通过内侧橄榄核的双侧投射。该模型假定，这条单突触通路中的活动，包括轴突传导时间加上一个突触延迟，反映在III-V波间期。如果上述两个假设都成立，那么IV-V波间期代表两条通路之间的差异，即跨越一个突触的传输时间。电生理ABR数据表明，IV-V间期直到一岁时才成熟。也可以将该模型应用于ABR的外周产生部分。假定仅代表第VIII神经轴突传导的I-II波间期在足月出生前就已接近成人水平。假定在耳蜗核复合体中含有一个突触的II-III间期，直到出生后1至2岁才达到成人水平。
