Department of Morphology/Laboratory of Chronobiology, Biosciences Center, Federal University of Rio Grande do Norte, 59072-970 Natal-RN, Brazil.
Neurosci Lett. 2010 May 7;475(1):38-43. doi: 10.1016/j.neulet.2010.03.040. Epub 2010 Mar 23.
The MD has reciprocal connections with the ventromedial prefrontal cortex (PFC) and with limbic cortices and appears to participate in learning and memory-related processes. In this study, we report the identification of a hitherto not reported direct retinal projection to the MD of the rock cavy, a typical rodent species of the Northeast region of Brazil. After unilateral intravitreal injections of cholera toxin subunit B (CTb), anterogradely transported CTb-imunoreactive fibers and presumptive terminals were seen in the MD. A few labeled retinal fibers/terminals detected in the MD of the rock cavy brain show clear varicosities, suggesting terminal fields. The present work is the first to show a direct retinal projection to the MD of rodents and may contribute for elucidating the anatomical substrate of the functional involvement of this thalamic nucleus in the modulation of the visual recognition, emotional learning and object-reward association memory.
MD 与腹内侧前额叶皮质（PFC）和边缘皮质有相互联系，似乎参与了学习和记忆相关的过程。在这项研究中，我们报告了一种迄今未被报道的直接视网膜投射到岩穴仓鼠 MD 的发现，岩穴仓鼠是巴西东北部地区的一种典型的啮齿动物。在单侧玻璃体内注射霍乱毒素亚单位 B（CTb）后，在 MD 中观察到顺行转运的 CTb 免疫反应纤维和假定的末端。在岩穴仓鼠脑的 MD 中检测到的一些标记的视网膜纤维/末端显示出明显的空泡，提示末端场。本工作首次显示了对啮齿动物 MD 的直接视网膜投射，可能有助于阐明该丘脑核在视觉识别、情绪学习和物体奖励关联记忆的调制中的功能参与的解剖学基础。
