Niklasson M, Stengård K, Tham R
Department of Otolaryngology, Faculty of Health Sciences, University Hospital, Linköping, Sweden.
Neurotoxicol Teratol. 1995 May-Jun;17(3):351-7. doi: 10.1016/0892-0362(94)00075-o.
The acute effects of toluene and a selective GABAB-antagonist, CGP 35348, on the vestibulo and opto-ocular motor (VOOM) system in rats were investigated by recording of compensatory eye-movements during vestibular and optokinetic stimulations. It has previously been demonstrated that toluene enhances the performance of the basic vestibulo-oculomotor reflex (VOR) and depresses the effects of the visual input to this reflex. It has been proposed that these effects are caused by alterations of the GABA-transmission system in the cerebellum. It has now been demonstrated that the exaggerating effects of toluene on the VOR, tested by angular horizontal acceleration/deceleration of the animals in darkness, are inhibited by CGP 35348 in a dose related way. On the contrary, the depressing effects on the visual input, tested by optokinetic stimulation, by angular acceleration/deceleration with a simultaneous conflicting visual stimulation and by eliciting saccades, could not be prevented by CGP 35348. The results support the hypothesis that toluene causes some of the effects on the VOOM system by influence on the GABA-transmission. The findings are in agreement with a recent report of increased levels of extracellular GABA in the cerebellar cortex during exposure to toluene.
通过记录大鼠在前庭和视动刺激期间的代偿性眼动，研究了甲苯和一种选择性GABAB拮抗剂CGP 35348对大鼠前庭和视眼动（VOOM）系统的急性影响。此前已证明，甲苯可增强基本前庭眼动反射（VOR）的表现，并抑制视觉输入对该反射的影响。有人提出，这些影响是由小脑GABA传递系统的改变引起的。现已证明，在黑暗中通过动物的角向水平加速/减速测试，甲苯对VOR的夸大作用会被CGP 35348以剂量相关的方式抑制。相反，通过视动刺激、同时进行冲突视觉刺激的角向加速/减速以及引发扫视来测试，CGP 35348无法阻止甲苯对视觉输入的抑制作用。这些结果支持了甲苯通过影响GABA传递对VOOM系统产生某些影响的假说。这些发现与最近一篇关于暴露于甲苯期间小脑皮质细胞外GABA水平升高的报告一致。
