Abou-Madi L, Pontarotti P, Tramu G, Cupo A, Eybalin M
INSERM-U. 254, Laboratoire de Neurobiologie de l'Audition, Hôpital St Charles, Montpellier, France.
Hear Res. 1987;30(2-3):135-46. doi: 10.1016/0378-5955(87)90131-6.
We have used the retrograde axonal transport of Fast Blue, injected intra-cochlearly, to identify in the rat lateral superior olive (LSO) neurons which belong to the lateral olivocochlear system (LOCS). Using immunohistofluorescence technique, we have localized within Fast Blue-labeled neurons immunostainings for enkephalins (Met-enkephalin, Met-enkephalin-Arg6-Gly7-Leu8), dynorphins (alpha-neo-endorphin, dynorphin 1-17) or choline acetyltransferase (ChAT). Many Fast Blue-labeled neurons did not show any immunostaining, but all the immunostained neurons found in the LSO were Fast Blue-labeled. In immunohistofluorescence colocalization experiments of two antigens, we could colocalize within the same neurons of the rat LSO immunostainings for ChAT and enkephalins and for ChAT and dynorphins. In each case, neurons only immunostained for ChAT, enkephalins or dynorphins could also be observed. A colocalization of the immunostainings for Met-enkephalin and dynorphins within neurons of the guinea pig and rat LSO was also found. However, in this case, neurons which did not show colocalization were only Met-enkephalin-immunoreactive, thus suggesting that all the dynorphins immunoreactive LSO neurons also contain enkephalins. These findings support the idea that the neurons of the LSO which contain ChAT-, enkephalin- or dynorphin-immunostainings project to the cochlea and belong to the LOCS. It can also be concluded that acetylcholine, enkephalins and dynorphins coexist within a same population of neurons of the LOCS, although other patterns of co-containment of neuroactive substances within LOCS neurons may also exist.
我们通过向耳蜗内注射快蓝，利用其逆行轴突运输来鉴定大鼠外侧上橄榄核（LSO）中属于外侧橄榄耳蜗系统（LOCS）的神经元。运用免疫荧光技术，我们在快蓝标记的神经元内定位了脑啡肽（甲硫氨酸脑啡肽、甲硫氨酸脑啡肽 - 精氨酸⁶ - 甘氨酸⁷ - 亮氨酸⁸）、强啡肽（α - 新内啡肽、强啡肽1 - 17）或胆碱乙酰转移酶（ChAT）的免疫染色。许多快蓝标记的神经元未显示任何免疫染色，但在LSO中发现的所有免疫染色神经元均为快蓝标记。在两种抗原的免疫荧光共定位实验中，我们在大鼠LSO的同一神经元内实现了ChAT与脑啡肽以及ChAT与强啡肽的免疫染色共定位。在每种情况下，也能观察到仅对ChAT、脑啡肽或强啡肽进行免疫染色的神经元。在豚鼠和大鼠LSO的神经元内还发现了甲硫氨酸脑啡肽和强啡肽免疫染色的共定位。然而，在这种情况下，未显示共定位的神经元仅对甲硫氨酸脑啡肽有免疫反应，这表明所有对强啡肽有免疫反应的LSO神经元也含有脑啡肽。这些发现支持了这样一种观点，即含有ChAT、脑啡肽或强啡肽免疫染色的LSO神经元投射至耳蜗且属于LOCS。还可以得出结论，乙酰胆碱、脑啡肽和强啡肽在LOCS的同一群神经元中共存，尽管LOCS神经元内可能还存在其他神经活性物质共含的模式。
