研究表明了動機如何幫助大腦記住特定的目標,，從而讓饑餓或口渴的大鼠可以使用記憶在迷宮中找到食物或水,。
Matthew Shapiro 和Pamela Kennedy追蹤了大腦中支持記憶的海馬區(qū)的特定神經(jīng)元的活動,，結(jié)果發(fā)現(xiàn)了當這些大鼠饑餓而尋找食物時與當它們口渴而在同一地點找水時,，這些神經(jīng)元以不同的方式觸發(fā),。海馬區(qū)的神經(jīng)元有“位置區(qū)”,，而且在當大鼠經(jīng)過它的環(huán)境中的一個特定區(qū)域時觸發(fā),。然而,，通過剝奪大鼠的食物或水，這組科學家建立了大鼠不同的內(nèi)部動機,，大鼠用這些動機在迷宮中走向含有食物或水的獎賞的特定已知目標,。當不同的動機狀態(tài)（饑餓或口渴）控制行為的時候，它們激活了大鼠海馬區(qū)神經(jīng)沖動的不同模式,，這既反映了大鼠的內(nèi)部刺激,，又反映了外部刺激。
這組作者說,，這些結(jié)果可能證明了動機如何影響記憶處理以及根據(jù)過去的經(jīng)驗幫助選擇不同的行為,。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS June 15, 2009, doi: 10.1073/pnas.0903259106
Motivational states activate distinct hippocampal representations to guide goal-directed behaviors
Pamela J. Kennedy and Matthew L. Shapiro,1
Adaptive behaviors are guided by motivation and memory. Motivational states specify goals, and memory can inform motivated behavior by providing detailed records of past experiences when goals were obtained. These 2 fundamental processes interact to guide animals to biologically relevant targets, but the neuronal mechanisms that integrate them remain unknown. To investigate these mechanisms, we recorded unit activity from the same population of hippocampal neurons as rats performed identical tasks while either food or water deprived. We compared the influence of motivational state (hunger and thirst), memory demand, and spatial behavior in 2 tasks: hippocampus-dependent contextual memory retrieval and hippocampus-independent random foraging. We found that: (i) hippocampal coding was most strongly influenced by motivational state during contextual memory retrieval, when motivational cues were required to select among remembered, goal-directed actions in the same places; (ii) the same neuronal populations were relatively unaffected by motivational state during random foraging, when hunger and thirst were incidental to behavior, and signals derived from deprivation states thus informed, but did not determine, hippocampal coding; and (iii) “prospective coding” in the contextual retrieval task was not influenced by allocentric spatial trajectory, but rather by the animal's deprivation state and the associated, non-spatial target, suggesting that hippocampal coding includes a wide range of predictive associations. The results show that beyond coding spatiotemporal context, hippocampal representations encode the relationships between internal states, the external environment, and action to provide a mechanism by which motivation and memory are coordinated to guide behavior.
