Eichenbaum H, Shedlack K J, Eckmann K W
Brain Behav Evol. 1980;17(4):255-75. doi: 10.1159/000121803.
The "core" subnucleus of the mediodorsal thalamic nucleus (MD) receives direct input from olfactory cortex in the rat. This part of MD projects to the frontal neocortex of the rhinal sulcus (RS), while other parts of the MD project to the anterior medial wall of the neocortex (MW). In this study, rats were tested on odor threshold, detection of specific odors, and three odor discriminations both before and after lesions of MD, MW, RS, or sham lesions. Olfactory threshold and detection ability remained unaffected by any of these lesions; however, subjects with MD and RS lesions were markedly impaired on odor discriminations. Furthermore, subjects were more profoundly impaired when the stimuli to be discriminated were novel or difficult to associate. Thus, MD and its "olfactory" projection target, RS, seem to mediate cognitive, rather than sensory aspects of odor-guided behavior in the rat.
大鼠丘脑背内侧核（MD）的“核心”亚核接收来自嗅觉皮质的直接输入。MD的这一部分投射到嗅沟（RS）的额叶新皮质，而MD的其他部分投射到新皮质的前内侧壁（MW）。在本研究中，在MD、MW、RS损伤或假损伤前后，对大鼠进行气味阈值、特定气味检测和三种气味辨别测试。嗅觉阈值和检测能力不受这些损伤的任何影响；然而，MD和RS损伤的受试者在气味辨别上明显受损。此外，当待辨别的刺激是新的或难以关联时，受试者受损更严重。因此，MD及其“嗅觉”投射靶点RS似乎介导了大鼠气味引导行为的认知方面，而非感觉方面。
