Perciavalle V
Institute of Human Physiology, University of Catania, Italy.
Neuroscience. 1987 Oct;23(1):243-51. doi: 10.1016/0306-4522(87)90286-7.
The influences exerted by the substantia nigra on reticulospinal neurons and the nature of the synaptic transmitter subserving these projections have been studied in adult cats and rats. Nigral stimulation evokes discharge changes in a significant number of reticulospinal cells (32.4% in cats and 39.1% in rats) on both ipsi- and contralateral sides. The responses were short-latency inhibitions (69.5% in cats and 76.5% in rats), short-latency excitations (22.2% in cats and 23.6% in rats) and in the remaining few cases long-latency excitations. Short-latency excitations, quite similar to the nigra-induced ones, were the predominant response pattern (95.2% in cats and 96.9% in rats) elicited on reticulospinal cells following stimulation of cerebral peduncle. The stimulation of substantia nigra in rats submitted to chronic ablation of sensorimotor cortex elicited only inhibitory responses while stimulation of nigral area in rats with intranigral injection of kainic acid was still capable of evoking short-latency excitations but not short-latency inhibitions. Therefore, the former can be ascribed to activation of corticoreticular fibers running in the cerebral peduncle whereas the latter can be considered as depending on activation of nigral efferents. The nigra-influenced cells were both 'fast' and 'slow' reticulospinal neurons and resulted mainly located in most rostral regions of reticular formation. Ionophoretic application of GABA suppressed the spontaneous firing of reticulospinal cells while no effect was observed following application of dopamine. The nigra-induced inhibitions were abolished by GABA-antagonist bicuculline and not by dopamine-antagonist fluphenazine.(ABSTRACT TRUNCATED AT 250 WORDS)
在成年猫和大鼠中，已经研究了黑质对网状脊髓神经元的影响以及维持这些投射的突触递质的性质。黑质刺激会引起同侧和对侧大量网状脊髓细胞的放电变化（猫中为32.4%，大鼠中为39.1%）。反应包括短潜伏期抑制（猫中为69.5%，大鼠中为76.5%）、短潜伏期兴奋（猫中为22.2%，大鼠中为23.6%），其余少数情况下为长潜伏期兴奋。短潜伏期兴奋与黑质诱导的兴奋非常相似，是刺激脑桥后网状脊髓细胞引发的主要反应模式（猫中为95.2%，大鼠中为96.9%）。对慢性切除感觉运动皮层的大鼠进行黑质刺激仅引发抑制性反应，而对黑质内注射 kainic 酸的大鼠进行黑质区域刺激仍能引发短潜伏期兴奋，但不能引发短潜伏期抑制。因此，前者可归因于脑桥中运行的皮质网状纤维的激活，而后者可被认为依赖于黑质传出纤维的激活。受黑质影响的细胞包括“快”和“慢”网状脊髓神经元，主要位于网状结构的最前端区域。离子电泳应用 GABA 可抑制网状脊髓细胞的自发放电，而应用多巴胺则未观察到效果。黑质诱导的抑制可被 GABA 拮抗剂荷包牡丹碱消除，而不能被多巴胺拮抗剂氟奋乃静消除。（摘要截断于250字）
