Evelyn F. McKnight Brain Institute, Arizona Research Laboratories Division of Neural Systems Memory and Aging, and Departments of Psychology, Neurology and Neuroscience, University of Arizona, Tucson, Arizona 85724.
J Neurosci. 2014 Jan 8;34(2):467-80. doi: 10.1523/JNEUROSCI.2875-13.2014.
The perirhinal cortex (PRC) is proposed to both represent high-order sensory information and maintain those representations across delays. These cognitive processes are required for recognition memory, which declines during normal aging. Whether or not advanced age affects the ability of PRC principal cells to support these dual roles, however, is not known. The current experiment recorded PRC neurons as young and aged rats traversed a track. When objects were placed on the track, a subset of the neurons became active at discrete locations adjacent to objects. Importantly, the aged rats had a lower proportion of neurons that were activated by objects. Once PRC activity patterns in the presence of objects were established, however, both age groups maintained these representations across delays up to 2 h. These data support the hypothesis that age-associated deficits in stimulus recognition arise from impairments in high-order stimulus representation rather than difficulty in sustaining stable activity patterns over time.
边缘下皮层（PRC）被认为既可以表示高级感觉信息，也可以在延迟期间维持这些表示。这些认知过程是识别记忆所必需的，而识别记忆在正常衰老过程中会下降。然而，高龄是否会影响 PRC 主细胞支持这两种作用的能力尚不清楚。在当前的实验中，当年轻和年老的大鼠在轨道上穿行时，记录了 PRC 神经元。当物体放在轨道上时，一小部分神经元在物体旁边的离散位置变得活跃。重要的是，年老的大鼠中被物体激活的神经元比例较低。然而，一旦在物体存在的情况下建立了 PRC 活动模式，两个年龄组都可以在长达 2 小时的时间内维持这些表示。这些数据支持这样的假设，即与年龄相关的刺激识别缺陷源于高级刺激表示的损伤，而不是随着时间的推移维持稳定活动模式的困难。
