Functional segregation of the medial temporal lobe
Our research focuses on the medial temporal lobe (MTL) areas, which are damaged in aging and amnesia resulting in severe memory deficits. Our aim is to characterize the specific contribution of each MTL area to memory function. We study the spatial and the temporal components of episodic memory, and the selective contribution of the MTL areas to encoding and retrieval, and to familiarity and recollection. We investigate memory function in healthy subjects, in aging and in animal models of amnesia by combining innovative behavioral memory paradigms with state-of-the-art imaging techniques.
The originality of our approach is to combine translational memory paradigms (standard human recognition memory tasks adapted to rodents) to selective stereotactic lesions, high resolution neuroanatomical imaging techniques and mutagenesis (see figure b). In addition, we are currently developing cognitive fMRI paradigms for awake rodents with the aim of bridging further human and animal recognition memory function. Moreover, we conduct behavioral human studies aiming at characterizing memory deficits seen in depressive and PTSD patients.
In collaboration with Eichenbaum's laboratory (BU,USA), we adapted ROC analysis to animals and showed that the hippocampus supports recollection, but not familiarity (Sauvage et al, Nature Neurosc., 2008). The molecular imaging picture represents an example of catFISH detection that we developed in collaboration with the Kitsukawa's laboratory (Osaka U., Japan).
Nakamura N, Flasbeck V, Maingret N, Kitsukawa T, Sauvage MM (2013) “Proximodistal segregation of non-spatial information in CA3: preferential involvement of a proximal CA3-distal CA1 network in non-spatial recognition memory?”, Journal of Neuroscience,33(28):11506-14
Place R, Lykken C, Beer Z, Suh J, McHugh T, Tonegawa S, Eichenbaum H and Sauvage M (2012) “NMDA signaling in CA1 mediates selectively the spatial component of episodic memory”, Learning and Memory, 14;19(4):164-9.
Eichenbaum H, Sauvage M, Fortin N, Komorowski R, Lipton P (2011) "Towards a functional organization of episodic memory in the medial temporal lobe". Neuroscience Biobehavioral Review. 36(7):1597-1608.
Sauvage M, Beer Z, Ho L, Eichenbaum H (2010) “The caudal medial entorhinal cortex: a selective role in recollection-based recognition memory“, Journal of Neuroscience, 17;30(46)15.
Sauvage M, Fortin N, Owens C, Yonelinas AP, Eichenbaum H (2008) "Recognition memory: opposite effects of hippocampal damage on recollection and familiarity“, Nature Neuroscience. 11(1):16-8 (highlighted in Nature Perspectives).