Bayer Hannah M, Handel Ari, Glimcher Paul W
Center for Neural Science, New York University, 4 Washington Place, Room 809, NY 10003, New York, USA.
Exp Brain Res. 2004 Feb;154(4):428-41. doi: 10.1007/s00221-003-1735-7. Epub 2004 Jan 15.
The substantia nigra pars reticulata (SNr), a major output nucleus of the basal ganglia, has been implicated anatomically, pharmacologically and physiologically in the generation of saccadic eye movements. However, the unique contribution of the SNr to saccade generation remains elusive. We studied the activity of SNr neurons while rhesus monkeys made saccades from different initial orbital positions, to determine what effects, if any, eye position had on SNr neuronal activity. We found that there was no effect of eye position on SNr neuronal responses. We also examined the responses of SNr neurons during memory-guided saccades to determine whether SNr discharges were affected by whether the target of the upcoming saccade was visible. We found that there was no change in response properties during memory saccade trials as compared to otherwise identical visually guided trials. SNr neurons appear to carry no information about either eye position or whether a movement is guided by a visible or remembered target. These results suggest that nigral signals are encoded in the same coordinate frame as those in the SC and FEF, but that unlike neuronal responses in these areas, SNr activity is not influenced by whether the saccade target remains visible until the movement is executed.
黑质网状部（SNr）是基底神经节的主要输出核团，在解剖学、药理学和生理学上均与扫视眼动的产生有关。然而，SNr对扫视产生的独特贡献仍不清楚。我们在恒河猴从不同初始眼眶位置进行扫视时研究了SNr神经元的活动，以确定眼位是否对SNr神经元活动有影响。我们发现眼位对SNr神经元反应没有影响。我们还检查了记忆引导扫视期间SNr神经元的反应，以确定即将到来的扫视目标是否可见是否会影响SNr的放电。我们发现，与其他相同的视觉引导试验相比，记忆扫视试验期间反应特性没有变化。SNr神经元似乎不携带关于眼位或运动是由可见目标还是记忆目标引导的任何信息。这些结果表明，黑质信号与上丘和额眼区的信号在相同的坐标框架中编码，但与这些区域的神经元反应不同，SNr活动不受扫视目标在运动执行前是否保持可见的影响。
