Fukushima K, Fukushima J, Terashima T
Department of Physiology, School of Medicine, Hokkaido University, Sapporo, Japan.
Exp Brain Res. 1987;68(1):88-102. doi: 10.1007/BF00255236.
(1) Experiments were performed in cats to examine effects of lesion of the interstitial nucleus of Cajal (INC) on head posture and the responsible pathway. Unilateral INC lesions resulted in lateral tilt of the head to the opposite side, and bilateral INC lesions resulted in dorsiflexion of the head as reported earlier. Such characteristic head posture was produced by successful kainic acid injections as well as by electrolytic lesions, suggesting that it was not due to damage of nerve fibers passing through the INC, but was produced most probably by damage of nerve cells in the INC. Electromyographic (EMG) recordings in unilateral INC-lesioned cats showed that activity was higher in the ipsilateral than in the contralateral major dorsal neck muscles (biventer, splenius, complexus, and rectus), and also higher in the contralateral than in the ipsilateral obliquus capitis caudalis muscle. The pattern of EMG activity was basically similar either when the cats presented typical head tilt or when their head was fixed to the frame at the stereotaxic plane. Characteristic head posture resulting from INC lesions seems consistent with the head posture produced by activation of these muscles. (2) Interruption of the medial and lateral vestibulospinal tracts did not significantly influence head tilt that had been produced by INC lesions. Characteristic head tilt was produced by INC lesions after cats had received bilateral labyrinthectomies, bilateral lesions of most of the vestibular nuclei, and bilateral aspiration of the cerebellar vermis and most of the lateral vestibular nuclei, indicating that typical head tilt can be produced without the vestibular nuclei and cerebellar vermis. (3) The medial longitudinal fasciculus (MLF) was interrupted at different levels to cut the major descending fibers from the INC. MLF interruption at the caudal midbrain produced typical head tilt, although MLF cut at the caudal pons and medulla was ineffective. Bilateral parasagittal cuts lateral to the MLF in the pons produced severe dorsiflexion of the head, and a subsequent unilateral INC lesion produced no further head tilt. These results suggest that fibers originating in the INC, removal of which is responsible for the typical head tilt, run through the MLF in the midbrain, and leave it in the pontine level.(ABSTRACT TRUNCATED AT 400 WORDS)
（1）在猫身上进行了实验，以研究 Cajal 间质核（INC）损伤对头部姿势及相关通路的影响。如先前报道，单侧 INC 损伤导致头部向对侧侧倾，双侧 INC 损伤导致头部背屈。成功注射 kainic 酸以及进行电解损伤均产生了这种特征性头部姿势，这表明它并非由于穿过 INC 的神经纤维受损所致，而极有可能是由 INC 中的神经细胞损伤引起的。对单侧 INC 损伤的猫进行肌电图（EMG）记录显示，同侧主要背颈部肌肉（二腹肌、夹肌、头半棘肌和头直肌）的活动高于对侧，而对侧头后斜肌的活动高于同侧。无论猫呈现典型的头部倾斜还是其头部在立体定向平面固定于框架时，EMG 活动模式基本相似。INC 损伤导致的特征性头部姿势似乎与这些肌肉激活所产生的头部姿势一致。（2）中断内侧和外侧前庭脊髓束对 INC 损伤所致的头部倾斜没有显著影响。在猫接受双侧迷路切除术、大部分前庭核的双侧损伤以及双侧小脑蚓部和大部分外侧前庭核的吸出术后，INC 损伤仍产生特征性头部倾斜，这表明典型的头部倾斜可在无前庭核和小脑蚓部的情况下产生。（3）在不同水平中断内侧纵束（MLF）以切断来自 INC 的主要下行纤维。在中脑尾部中断 MLF 产生典型的头部倾斜，而在脑桥尾部和延髓切断 MLF 则无效。在脑桥 MLF 外侧进行双侧矢状旁切口导致头部严重背屈，随后单侧 INC 损伤未产生进一步的头部倾斜。这些结果表明，起源于 INC 的纤维，其去除会导致典型的头部倾斜，这些纤维在中脑穿过 MLF，并在脑桥水平离开 MLF。（摘要截取自 400 字）
