Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC 29208, USA.
Neurosci Lett. 2012 Mar 5;511(1):38-42. doi: 10.1016/j.neulet.2012.01.033. Epub 2012 Jan 24.
Several lines of evidence point to a role for the hippocampal formation and contiguous temporal lobe structures in a variety of learning and memory paradigms. Presumably, these cognitive phenomena are mediated (and accompanied) by dynamic changes in neurochemical transmission that may differ between learning and recall phases. However, the neurotransmitter correlates of most memory-related tasks have not been thoroughly investigated. Here we used a one-trial object recognition paradigm paired with in vivo microdialysis to assess hippocampal acetylcholine (ACh), glutamate and GABA efflux when rats were exposed to familiar objects, and when given the option to explore familiar and novel objects. Rats preferentially explored the novel object over the familiar one when presented with the option. Regardless of object familiarity, object exploration was accompanied by an increase in hippocampal ACh efflux, while GABA efflux was unaffected. However, glutamate efflux was not increased above baseline levels by presentation of familiar objects, but was significantly enhanced in the presence of the novel object. These data suggest that the hippocampus, and in particular, hippocampal glutamate, may be involved in memory processes during novelty recognition paradigms.
有几条证据表明，海马结构和相邻的颞叶结构在各种学习和记忆模式中起作用。可以推测，这些认知现象是由神经化学传递的动态变化介导（并伴随）的，而这种变化在学习和回忆阶段可能有所不同。然而，大多数与记忆相关任务的神经递质相关性尚未得到彻底研究。在这里，我们使用单次物体识别范式与体内微透析相结合，当大鼠接触熟悉的物体以及有选择地探索熟悉和新物体时，评估海马乙酰胆碱 (ACh)、谷氨酸和 GABA 的外排。当提供选择时，大鼠更倾向于探索新物体而不是熟悉的物体。无论物体的熟悉程度如何，物体探索都会伴随着海马 ACh 外排的增加，而 GABA 外排不受影响。然而，当呈现熟悉的物体时，谷氨酸外排并没有高于基线水平，而是在新物体存在时显著增强。这些数据表明，海马体，特别是海马体中的谷氨酸，可能参与新颖性识别范式中的记忆过程。
