Connections of eye-saccade-related areas within mesencephalic reticular formation with the optic tectum in goldfish.

摘要: Physiological studies demonstrate that separate sites within the mesencephalic reticular formation (MRF) can evoke eye saccades with different preferred directions. Furthermore, anatomical research suggests a tectoreticulotectal circuit organized in accordance tectal movement map is present. However, whether reticulotectal projection shifts gaze present MRF unknown. We explored this question goldfish, by injecting biotin dextran amine evoked upward, downward, oblique, and horizontal saccades. Then, we analyzed labeling optic tectum. The main findings be summarized as follows. 1) tectum were connected axons of tectobulbar tract. 2) was reciprocally mainly ipsilateral lobe, but also contralateral one. 3) received projections chiefly from neurons located intermediate deep layers. In addition, terminated primarily layer. 4) distribution labeled shifted manner consistent motor map. area containing these cells targeted high-density projection. addition to topographic projection, there low-density one spread throughout 5) Occasionally, boutons observed adjacent neurons. conclude organization functional topography participates feedback circuit. J. Comp. Neurol. 500:6–19, 2007. © 2006 Wiley-Liss, Inc.