Thaker G K, Nguyen J A, Tamminga C A
Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland, Baltimore 21228.
Biol Psychiatry. 1989 Jan;25(1):49-59. doi: 10.1016/0006-3223(89)90146-7.
In mammals, GABAergic projections from the substantia nigra reticulata to the superior colliculus provide tonic inhibition to tectal neurons involved in the generation of saccades. Dysfunction of this pathway has been shown to produce saccadic "distractibility" in the experimental monkey. In two oculomotor paradigms, control of saccadic eye movements was tested in chronic schizophrenic patients with (n = 18) and without (n = 16) tardive dyskinesia (TD) and normal controls (n = 8). The three groups were matched by mean age; the TD and non-TD patient groups had similar duration of illness, benztropine and chlorpromazine equivalent doses and educational levels. A twofold increase in saccadic distractibility was observed in TD compared to non-TD schizophrenic patients, and both patient groups demonstrated a greater saccadic distractibility than normals. Furthermore, schizophrenic patients (both with and without TD) showed significantly increased latency for "volitional" saccades compared to the normal controls. These findings may provide further evidence for basal ganglia GABA dysfunction in tardive dyskinesia, as well as demonstrate oculomotor abnormalities in schizophrenic individuals.
在哺乳动物中，从黑质网状部到上丘的γ-氨基丁酸能投射对参与扫视运动产生的顶盖神经元提供紧张性抑制。该通路功能障碍已被证明会在实验猴中产生扫视“易分散性”。在两种眼动范式中，对患有（n = 18）和未患有（n = 16）迟发性运动障碍（TD）的慢性精神分裂症患者以及正常对照（n = 8）进行了扫视眼动控制测试。三组按平均年龄匹配；TD和非TD患者组的病程、苯海索和氯丙嗪等效剂量以及教育水平相似。与非TD精神分裂症患者相比，TD患者的扫视易分散性增加了两倍，并且两个患者组的扫视易分散性均高于正常对照组。此外，与正常对照组相比，精神分裂症患者（无论有无TD）的“随意性”扫视潜伏期显著延长。这些发现可能为迟发性运动障碍中基底神经节γ-氨基丁酸功能障碍提供进一步证据，同时也证明了精神分裂症个体存在眼动异常。
