神经生物学科学家通常将人类的记忆分为三类：陈述性记忆(declarative memory)，如记忆某个特殊事件；程序性记忆(procedural memory)，如学习弹钢琴或者灌篮；工作记忆(working memory)，如短时记忆一个电话号码等。
在一项即将发表于2010年Nature Neuroscience杂志二月版的一项研究报告中，凯斯西储大学医学院Strowbridge和Larimer等人对负责人类工作记忆的大脑神经回路进行研究。
通过分离出老鼠的大脑组织，研究人员发现可以在活体内建立工作记忆模式。Larimer对大脑海马体中一种称为mossy细胞的神经元进行研究，癫痫病患者通常mossy细胞发生受损。
Mossy细胞有一个重要特点——即使在很薄的脑切片中，Mossy细胞也能维持正常的活性。当研究人员将刺激电极插入到海马体大脑切片中，Mossy细胞自发的电活性在电极的刺激下被激活。活体的记忆能够维持10秒钟，这相当于人类工作记忆的时间长度。
科学家测试了mossy细胞突触输入的频率，以此来检验海马体是否保留了记忆的能力。据Strowbridge介绍，这是首次利用哺乳动物大脑组织的脑切片测试其记忆存储能力。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature Neuroscience 27 December 2009 | doi:10.1038/nn.2458
Representing information in cell assemblies: persistent activity mediated by semilunar granule cells
Phillip Larimer1 & Ben W Strowbridge1
Here we found that perforant path stimulation in rat hippocampal slices evoked long-lasting barrages of synaptic inputs in subpopulations of dentate gyrus mossy cells and hilar interneurons. Synaptic barrages triggered persistent firing in hilar neurons (hilar up-states). We found that synaptic barrages originate from semilunar granule cells (SGCs), glutamatergic neurons in the inner molecular layer that generate long-duration plateau potentials in response to excitatory synaptic input. MK801, nimodipine and nickel all abolished both stimulus-evoked plateau potentials in SGCs and synaptic barrages in downstream hilar neurons without blocking fast synaptic transmission. Hilar up-states triggered functional inhibition in granule cells that persisted for more than 10 s. Hilar cell assemblies, identified by simultaneous triple and paired intracellular recordings, were linked by persistent firing in SGCs. Population responses recorded in hilar neurons accurately encoded stimulus identity. Stimulus-evoked up-states in the dentate gyrus represent a potential cellular basis for hippocampal working memory.
1 Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio, USA.
