大鼠展神经核和前庭神经核内GABA反应神经元向动眼神经核的投射

用辣根过氧化物酶(horseradish peroxidase,HRP)逆行标记结合γ-氨基丁酸(γ-amino-butyric acid,GABA)的免疫组织化学双标技术观察大鼠的展神经核和前庭神经核内GABA阳性神经元的分布,以及其向动眼神经核的投射。结果表明:注射HRP于大鼠动眼神经核内直肌亚核后,在对侧展神经核区以及前庭神经核、脑桥旁正中网状结构中发现HRP单标记细胞;在前庭神经核内,可见HRP单标记、GABA阳性和HRP/GABA双标记三类神经元,其中HRP/GABA双标记细胞占HRP标记细胞总数的47.1%。结果表明GABA在前庭神经核向动眼神经核的抑制性投射中起一定作用,而在展神经核向动眼神经核投射的核间通路中,可能不是起主要作用的抑制性神经递质。

PROJECTION OF GABA-IMMUNOREACTIVE NEURONS IN ABDUCENS AND VESTIBULAR NUCLEUS TO OCULOMOTOR NUCLEUS IN RATS

The double labelling technique by combination of horseradish peroxidase(HRP)retrograde tracing with immunohistochemical staining for γ-amino-butyric acid(GABA)was used to observe the distribution of GABA-positive neurons in the abducens and vestibular nucleus,and its projection to oculomotor nucleus of rats.Results showed that after injection of HRP into medial recteus subnucleus of oculomotor nucleus,HRP labelled cells were found in contralateral abducens nucleus and also in vestibular nucleus and pontine paramedian reticular formation(PPRF);In vestibular nucleus,three kinds of neurons including HRP labelled,GABA positive and HRP/GABA double-labelled neurons were found.Among them,HRP/GABA double-labelled neurons were accounted for 47.1% of total HRP labelled cells.These results suggest that GABA plays roles in the inhibitory projection from vestibular nucleus to oculomotor nucleus.However,it may be not the main inhibitory neurotransmitter in the internuclear pathway from abducens nucleus to oculomotor nucleus.