Olivocochlear and vestibular efferent neurons of the feline brain stem: Their location, morphology and number determined by retrograde axonal transport and acetylcholinesterase histochemistry
Olivocochlear and vestibular efferent neurons of the feline brain stem: Their location, morphology and number determined by retrograde axonal transport and acetylcholinesterase histochemistry
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猫脑干的橄榄耳蜗和前庭传出神经元：它们的位置、形态和数量由逆行轴突运输和乙酰胆碱酯酶组织化学决定
DOI：
10.1002/cne.901610203
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发表时间：
1975
影响因子：
2.5
通讯作者：
W. Warr
中科院分区：
文献类型：
--
作者：
W. Warr
Anterograde degeneration studies have shown that the cochlear and vestibular receptor organs receive an efferent innervation from neurons in the brain stem. This pathway may provide a mechanism by which the CNS could modulate its own afferent input. The neurons which provide this innervation have so far escaped positive identification with methods which depend on retrograde cell changes after axotomy. In the present study, horseradish peroxidase (HRP) was injected into the labryinths of kittens and after allowing 24 hours for the retrograde axonal transport of this tracer, its presence in neurons of the brain stem was demonstrated histochemically. Because there is evidence that the efferent innervation of the labyrinth is cholinergic, acetylcholinesterase (AChE) was also demonstrated histochemically in the same or in adjacent tissue sections. Neurons labelled with HRP were found bilaterally in most periolivary cell groups of the superior olivary complex (cochlear efferents) and in the parvocellular reticular nucleus lateral to the abducens nucleus (vestibular efferents). Counts of labelled neurons yielded estimated totals of 1,700–1,800 cochlear and 400–500 vestibular efferent neurons. Approximately 60% of the neurons in each total were located on the side ipsilateral to the injection. The distribution of HRP‐labelled neurons was virtually identical to that of AChE‐positive neurons found in adjacent sections, and in those regions with predominantly ipsilateral or contralateral projections, there was an approximate correspondence in number of HRP‐ and AChE‐positive neurons. In tissue sections processed successively for demonstration of HRP and AChE, virtually all HRP‐labelled neurons were found to be AChE‐positive. These findings suggest that a number of current conceptions regarding labyrinthine efferent systems may need revision.
