Section of Neuroanatomy, Yale University School of Medicine.
J Cogn Neurosci. 1990 Winter;2(1):18-31. doi: 10.1162/jocn.1990.2.1.18.
The 2-deoxyglucose (2-DG) method was used to study the effect of working memory processing on local cerebral glucose utilization (LCGU) in the diencephalon of the rhesus monkey. Monkeys were given [(14)C]2-DG while performing either one of three tasks that engaged working memory (WORK group) or one of two control tasks (CONT group) that used associative or non associative processes. The tasks of the WORK group-spatial delayed response, spatial delayed alternation, and delayed object alternation-are alike in that the information guiding a correct response changes from trial to trial and only the accurate record of the preceding response (or cue) is relevant for each successive trial. The CONT group, in contrast, performed on either a visual pattern discrimination test, in which the correct stimulus-response association was invariant across all trials and all test sessions, or on a sensorimotor task in which there was no explicit memory requirement. LCGU was examined in five diencephalic regions: the mammillary bodies, the anteroventral and anteromedial thalamus, and the parvocellular and magnocellular components of the mediodorsal thalamic nucleus. Comparisons across the two groups showed that mean LCGU in the anterior and mediodorsal thalamic nuclei was significantly elevated (by 12-16%) in the WORK group relative to the CONT group. Mean LCGU in the mammillary bodies also was higher in the WORK group than in the CONT group, but this difference was not significant. The present findings suggest that the anterior and mediodorsal thalamic nuclei represent diecephalic components of a neural network processing working memory. Together with our previous report on the enhancement of metabolic activity in the hippocampus and dentate gyrus, these results show that working memory has a wide-ranging influence on cerebral metabolism and emphasize the cooperative, rather than dissociable, roles of the hippocampus and medial thalamus in this function.
采用 2-脱氧葡萄糖（2-DG）方法研究了工作记忆处理对猕猴间脑局部脑葡萄糖利用率（LCGU）的影响。猴子在执行三种需要工作记忆的任务之一（WORK 组）或两种使用联想或非联想过程的对照任务之一（CONT 组）时给予[14C]2-DG。WORK 组的任务——空间延迟反应、空间延迟交替和延迟物体交替——在信息引导正确反应从一次试验到另一次试验变化，只有前一次反应（或提示）的准确记录对每个后续试验相关方面是相似的。相比之下，CONT 组进行的是视觉模式辨别测试，其中正确的刺激-反应联想在所有试验和所有测试过程中都是不变的，或者进行的是感觉运动任务，其中没有明确的记忆要求。在五个间脑区域检查了 LCGU：乳头体、前腹侧和前内侧丘脑以及中背侧丘脑的小细胞和大细胞成分。两组之间的比较表明，与 CONT 组相比，WORK 组的前丘脑和中背侧丘脑的平均 LCGU 显著升高（12-16%）。WORK 组的乳头体的平均 LCGU 也高于 CONT 组，但这种差异没有统计学意义。本研究结果表明，前丘脑和中背侧丘脑是处理工作记忆的神经网络的间脑成分。结合我们之前关于海马体和齿状回代谢活性增强的报告，这些结果表明工作记忆对大脑代谢有广泛的影响，并强调了海马体和内侧丘脑在这一功能中的协作作用，而不是可分离的作用。
