EFFERENT PROJECTIONS OF VENTRAL ANTERIOR NUCLEUS OF THALAMUS IN MONKEY
EFFERENT PROJECTIONS OF VENTRAL ANTERIOR NUCLEUS OF THALAMUS IN MONKEY
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DOI：
10.1002/aja.1001280204
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发表时间：
1970-01-01
影响因子：
--
通讯作者：
CARMEL, PW
中科院分区：
文献类型：
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作者：
CARMEL, PW
本实验观察了20只猕猴丘脑腹前核(VA)的传出投射。在这些动物中，有一半在核的大细胞(Vamc)或小细胞(VApc)部分进行立体定位损伤后可追踪到变性。在其余动物中，研究了不同皮质消融后VA核的慢性细胞变化。VA核的立体定向损伤导致广泛的皮质下变性(Nauta或Marchi染色)。在VA核内有致密的变性纤维，主要定向于矢状面。VAMC核的纤维向外侧投射到VApc核。在VA核内出现大量的尾侧定向纤维，投射到丘脑前部、层内核和束旁核。纤维也进入了中央正中核和背内侧核的一部分。来自VA核的吻侧定向纤维进入内囊前肢，广泛分布于额叶皮质。VA内侧核(VAMC)的吻侧投射部分定位于部分眶前叶皮质。丘脑其他腹侧层核无或稀疏变性，纹状体、苍白球或岛叶皮质未见变性。4区、6区、眶皮质、内侧额叶皮质或岛叶皮质的狭窄皮质损毁对VA核无细胞改变。大面积损毁累及多个额叶皮质导致细胞改变，但不像邻近的腹外侧核那样严重；广泛消融后，大约一半的VA细胞保持正常。VA核似乎是丘脑非特异性系统中的重要纽带。传出投射既到达非特异性丘脑核团，也到达额叶皮质的广泛区域。
Efferent projections of the ventral anterior (VA) thalamic nucleus were investigated in 20 monkeys. In half of these animals degeneration was traced following stereotaxic lesions in the magnocellular (VAmc) or parvocellular (VApc) portions of the nucleus. Chronic cell changes in the VA nucleus were studied following various cortical ablations in the remaining animals.Stereotaxic lesions in the VA nucleus produced extensive subcortical degeneration (Nauta or Marchi stains). Within the VA nucleus was a dense pattern of degenerated fibers, largely oriented in the sagittal plane. Fibers from the VAmc nucleus projected laterally into the VApc nucleus. Numerous caudally directed fibers arose in the VA nucleus and projected intrathalamically to the rostral intralaminar and parafascicular nuclei. Fibers also entered portions of the centromedian and dorsomedial nuclei. Rostrally directed fibers from the VA nucleus entered the anterior limb of the internal capsule and were distributed widely to the frontal lobe cortex. Rostral projections from the medial VA (VAmc) nucleus were, in part, localized to a portion of the orbitofrontal cortex.Degeneration was absent or sparse in other ventral tier thalamic nuclei, and no degeneration was seen in the striatum, pallidum or insular cortex.Restricted cortical lesions in area 4, area 6, orbital cortex, medial frontal cortex, or insular cortex produced no cellular alteration in the VA nucleus. Large lesions involving several frontal cortical areas resulted in cellular changes, which were not as severe as in the adjacent ventrolateral nuclei; after extensive ablations approximately half of the VA cells remained normal.The VA nucleus appears to be an important link in the thalamic nonspecific system. Efferent projections reach both the nonspecific thalamic nuclei and widespread areas of frontal cortex.