May-Britt Moser and Edvard Moser are Professors and Directors at the Kavli Institute and the Centre for Neural Computation.
They are interested in the fundamental neural computations underlying cognition and behaviour. To decipher these computations, they focus on the mechanisms for mapping of local space in the mammalian cortex. Their past work includes the discovery of grid cells.
Why grid cells?
In mammals, great insights have been obtained for early stages of sensory systems where signals can be followed through hierarchical networks from receptors to primary sensory cortices. But how the mammalian brain generates its own codes, deep in the association cortices, has remained deeply mysterious. Yet this is where the understanding of subjective experience begins. A path was opened in this terra incognita in 2005 when the Mosers and their students discovered grid cells – the metric of the brain's map for space.
Grid cells are place-modulated neurons whose firing fields define a triangular array across the entire environment.
These cells are thought to form an essential part of the brain's coordinate system for metric navigation. Because their matrix-like firing is generated in the brain, far away from specific sensory inputs, grid cells provide unprecedented access to algorithms of neural coding in high-end cortices.
The simplicity and the crystal-like structure of the grid cells offers opportunities for understanding, maybe for the first time, a mammalian behaviour at the level of neuronal network computation.
Brun, V.H., Otnæss, M.K., Molden, S., Steffenach, H.-A., Witter, M.P., Moser, M.-B., Moser, E.I. (2002). Place cells and place representation maintained by direct entorhinal-hippocampal circuitry. Science, 296, 2089-2284.
Fyhn, M., Molden, S., Witter, M.P., Moser, E.I. and Moser, M.-B. (2004). Spatial representation in the entorhinal cortex. Science, 305, 1258-1264.
Leutgeb, S., Leutgeb, J.K., Treves, A., Moser, M.-B. and Moser, E.I. (2004). Distinct ensemble codes in hippocampal areas CA3 and CA1. Science 305, 1295-1298.
Leutgeb, S., Leutgeb, J.K., Barnes, C.A., Moser, E.I., McNaughton, B.L., and Moser, M.-B (2005). Independent codes for spatial and episodic memory in the hippocampus. Science, 309, 619-623.
Hafting, T., Fyhn, M., Molden, S., Moser, M.-B., and Moser, E.I. (2005). Microstructure of a spatial map in the entorhinal cortex. Nature, 436, 801-806.
Sargolini, F., Fyhn, M., Hafting, T., McNaughton, B.L., Witter, M.P., Moser, M.-B., and Moser, E.I. (2006). Conjunctive representation of position, direction and velocity in entorhinal cortex. Science, 312, 754-758.
Leutgeb, J.K., Leutgeb, S., Moser, M.-B., and Moser, E.I. (2007). Pattern separation in dentate gyrus and CA3 of the hippocampus. Science , 315, 961-966.
Fyhn, M., Hafting, T., Treves, A., Moser, M.-B. and Moser, E.I. (2007). Hippocampal remapping and grid realignment in entorhinal cortex. Nature, 446, 190-194.
Hafting, T., Fyhn, M., Bonnevie, T., Moser, M.-B. and Moser, E.I. (2008). Hippocampus-independent phase precession in entorhinal grid cells. Nature 453, 1248-1252.
Kjelstrup, K.B., Solstad, T., Brun, V.H., Hafting, T., Leutgeb, S., Witter, M.P., Moser, E.I. and Moser, M.-B. (2008). Finite scales of spatial representation in the hippocampus. Science 321, 140-143.
Solstad, T., Boccara, C.N., Kropff, E., Moser, M.-B. and Moser, E.I. (2008). Representation of geometric borders in the entorhinal cortex. Science, 322, 1865-1868.
Colgin LL, Denninger T, Fyhn M, Hafting T, Bonnevie T, Jensen O, Moser M-B and Moser, EI (2009). Frequency of gamma oscillations routes flow of information in the hippocampus. Nature, 462, 353-357.
Langston RF, Ainge J, Cowey JJ, Canto CB, Bjerknes TL, Witter MP, Moser EI, Moser M-B (2010). Development of the spatial representation system in the rat. Science, 328, 1576-1580.
Jezek K, Henriksen EJ, Treves A, Moser EI and Moser (2011). Theta-paced flickering between place-cell maps in the hippocampus. Nature, 478, 246-249.
Giocomo LM, Hussaini SA, Zheng F, Kandel ER, Moser M-B and Moser EI (2011). Grid cells use HCN1 channels for spatial scaling. Cell, 147, 1159-1170.
Stensola H, Stensola T, Solstad T, Frøland K, Moser M-B and Moser EI (2012). The entorhinal grid map is discretized. Nature, 492, 72-78.
Couey JJ, Witoelar A, Zhang S-J, Zheng K, Ye J, Dunn B, Czajkowski R, Moser M-B, Moser EI, Roudi Y, Witter MP (2013). Recurrent inhibitory connectivity between entorhinal layer II stellate cells is sufficient to generate grid-cell patterns. Nature Neurosci., 16, 318-324.
Bonnevie T, Dunn B, Fyhn M, Hafting T, Derdikman D, Kubie JL, Roudi Y, Moser EI and Moser M-B (2013). Grid cells require excitatory drive from the hippocampus. Nature Neurosci., 16, 309-317.
Zhang S-J, Ye J, Miao C, Tsao A, Cerniauskas I, Ledergerber D, Moser M-B and Moser EI (2013). Optogenetic dissection of entorhinal-hippocampal functional connectivity. Science, 340, 1232627.
Lu L, Leutgeb JK, Tsao A, Henriksen EJ, Leutgeb S, Barnes CA, Witter MP, Moser M-B and Moser EI (2013). Impaired hippocampal rate coding after lesions of the lateral entorhinal cortex. Nature Neurosci., 16, 1085-1093.
Bjerknes TL, Moser EI, Moser M-B (2014). Representation of geometric borders in the developing rat. Neuron, 82, 71-78.
Igarashi KM, Lu L, Colgin LL, Moser M-B, Moser EI (2014). Coordination of entorhinal-hippocampal ensemble activity during associative learning. Nature, 510, 143-147.
Moser EI, Roudi Y, Witter MP, Kentros C, Bonhoeffer T, Moser M-B (2014). Grid cells and cortical representation. Nature Reviews Neuroscience, 15, 466-481.
Strange BA, Witter MP, Lein BS, Moser EI (2014). Functional organization of the hippocampal longitudinal axis. Nature Reviews Neuroscience, 15, 655-669.
Alme CB, Miao C, Jezek K, Treves A, Moser EI, Moser M-B (2014). Place cells in the hippocampus: Eleven maps for eleven rooms. Proceedings of the National Academy of the Sciences USA, 111, 18428-18435.
Stensola T, Stensola H, Moser M-B, Moser EI (2015). Shearing-induced asymmetry in entorhinal grid cells. Nature, 518, 207-212 (Article).
Ito HT, Zhang S-J, Witter MP, Moser EI, Moser M-B (2015). A prefrontal-thalamo-hippocampal circuit for goal-directed spatial coding. Nature, 522, 50-55 (Article).
Kropff E, Carmichael JE, Moser M-B, Moser EI (2015). Speed cells in medial entorhinal cortex. Nature, in press (Article).