神經生物學科學家通常將人類的記憶分為三類：陳述性記憶(declarative memory),，如記憶某個特殊事件；程序性記憶(procedural memory),，如學習彈鋼琴或者灌籃,；工作記憶(working memory)，如短時記憶一個電話號碼等,。

在一項即將發(fā)表于2010年Nature Neuroscience雜志二月版的一項研究報告中,，凱斯西儲大學醫(yī)學院Strowbridge和Larimer等人對負責人類工作記憶的大腦神經回路進行研究,。

通過分離出老鼠的大腦組織，研究人員發(fā)現可以在活體內建立工作記憶模式,。Larimer對大腦海馬體中一種稱為mossy細胞的神經元進行研究,，癲癇病患者通常mossy細胞發(fā)生受損。

Mossy細胞有一個重要特點——即使在很薄的腦切片中,，Mossy細胞也能維持正常的活性,。當研究人員將刺激電極插入到海馬體大腦切片中，Mossy細胞自發(fā)的電活性在電極的刺激下被激活,?；铙w的記憶能夠維持10秒鐘，這相當于人類工作記憶的時間長度,。

科學家測試了mossy細胞突觸輸入的頻率,，以此來檢驗海馬體是否保留了記憶的能力。據Strowbridge介紹,，這是首次利用哺乳動物大腦組織的腦切片測試其記憶存儲能力,。（生物谷Bioon.com）

生物谷推薦原始出處：

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.