Torkel Hafting

• Buccino, Alessio Paolo; Lepperød, Mikkel Elle; Dragly, Svenn-Arne; Häfliger, Philipp; Fyhn, Marianne & Hafting, Torkel (2018). Open source modules for tracking animal behavior and closed-loop stimulation based on Open Ephys and Bonsai. Journal of Neural Engineering.  ISSN 1741-2560.  15, s 1- 12 . doi: 10.1088/1741-2552/aacf45 Full text in Research Archive.
• Dragly, Svenn-Arne; Mobarhan, Milad; Lepperød, Mikkel Elle; Tennøe, Simen; Fyhn, Marianne; Hafting, Torkel & Malthe-Sørenssen, Anders (2018). Experimental directory structure (Exdir): An alternative to HDF5 without introducing a new file format. Frontiers in Neuroinformatics.  ISSN 1662-5196.  12 . doi: 10.3389/fninf.2018.00016
• Mobarhan, Milad; Halnes, Geir; Martínez-Cañada, Pablo; Hafting, Torkel; Fyhn, Marianne & Einevoll, Gaute (2018). Firing-rate based network modeling of the dLGN circuit: Effects of cortical feedback on spatiotemporal response properties of relay cells. PloS Computational Biology.  ISSN 1553-734X.  14(5) . doi: 10.1371/journal.pcbi.1006156 Full text in Research Archive.
• Rowlands, Daire; Lensjø, Kristian Kinden; Dinh, Tovy; Yang, Sujeon; Andrews, Melissa; Hafting, Torkel; Fyhn, Marianne; Fawcett, James W. & Dick, Gunnar (2018). Aggrecan directs extracellular matrix mediated neuronal plasticity. Journal of Neuroscience.  ISSN 0270-6474. . doi: 10.1523/JNEUROSCI.1122-18.2018 Show summary

  In the adult brain, the extracellular matrix (ECM) influences recovery after injury, susceptibility to mental disorders, and is in general a strong regulator of neuronal plasticity. The proteoglycan aggrecan is a core component of the condensed ECM structures termed perineuronal nets (PNNs), and the specific role of PNNs on neural plasticity remains elusive. Here, we genetically targeted the Acan gene encoding for aggrecan utilizing a novel animal model. This allowed for conditional and targeted loss of aggrecan in vivo, which ablated the PNN structure and caused a shift in the population of parvalbumin expressing inhibitory interneurons towards a high plasticity state. Selective deletion of the Acan gene in the visual cortex of male adult mice reinstated juvenile ocular dominance plasticity, which was mechanistically identical to critical period plasticity. Brain-wide targeting improved object recognition memory.

• Thompson, Elise Holter; Lensjø, Kristian Kinden; Wigestrand, Mattis B; Malthe-sørenssen, Anders; Hafting, Torkel & Fyhn, Marianne (2018). Removal of perineuronal nets disrupts recall of a remote fear memory. Proceedings of the National Academy of Sciences of the United States of America.  ISSN 0027-8424.  115(3), s 607- 612 . doi: 10.1073/pnas.1713530115 Full text in Research Archive.
• Aasebø, Ida E. J.; Lepperød, Mikkel Elle; Stavrinou, Maria; Nøkkevangen, Sandra; Einevoll, Gaute; Hafting, Torkel & Fyhn, Marianne (2017). Temporal processing in the visual cortex of the awake and anesthetized rat. eNeuro.  ISSN 2373-2822.  4:e0059-17.2017(4), s 1- 26 . doi: 10.1523/ENEURO.0059-17.2017 Full text in Research Archive. Show summary

  The activity pattern and temporal dynamics within and between neuron ensembles are essential features of information processing and believed to be profoundly affected by anesthesia. Much of our general understanding of sensory information processing, including computational models aimed at mathematically simulating sensory information processing, rely on parameters derived from recordings conducted on animals under anesthesia. Due to the high variety of neuronal subtypes in the brain, population-based estimates of the impact of anesthesia may conceal unit- or ensemble-specific effects of the transition between states. Using chronically implanted tetrodes into primary visual cortex (V1) of rats, we conducted extracellular recordings of single units and followed the same cell ensembles in the awake and anesthetized states. We found that the transition from wakefulness to anesthesia involves unpredictable changes in temporal response characteristics. The latency of single-unit responses to visual stimulation was delayed in anesthesia, with large individual variations between units. Pair-wise correlations between units increased under anesthesia, indicating more synchronized activity. Further, the units within an ensemble show reproducible temporal activity patterns in response to visual stimuli that is changed between states, suggesting state-dependent sequences of activity. The current dataset, with recordings from the same neural ensembles across states, is well suited for validating and testing computational network models. This can lead to testable predictions, bring a deeper understanding of the experimental findings and improve models of neural information processing. Here, we exemplify such a workflow using a Brunel network model.

• Dragly, Svenn-Arne; Mobarhan, Milad; Solbrå, Andreas Våvang; Tennøe, Simen; Hafreager, Anders; Malthe-Sørenssen, Anders; Fyhn, Marianne; Hafting, Torkel & Einevoll, Gaute (2017). Neuronify: An educational simulator for neural circuits. eNeuro.  ISSN 2373-2822.  4(2:e0022-17.2017), s 1- 13 . doi: 10.1523/ENEURO.0022-17.2017 Full text in Research Archive.
• Lensjø, Kristian Kinden; Christensen, Ane Charlotte; Tennøe, Simen; Fyhn, Marianne & Hafting, Torkel (2017). Differential Expression and Cell-Type Specificity of Perineuronal Nets in Hippocampus, Medial Entorhinal Cortex and Visual Cortex Examined in the Rat and Mouse. eNeuro.  ISSN 2373-2822.  4(3), s 1- 18 . doi: 10.1523/ENEURO.0379-16.2017 Full text in Research Archive.
• Lensjø, Kristian Kinden; Lepperød, Mikkel Elle; Dick, Gunnar; Hafting, Torkel & Fyhn, Marianne (2017). Removal of perineuronal nets unlocks juvenile plasticity through network mechanisms of decreased inhibition and increased gamma Activity. Journal of Neuroscience.  ISSN 0270-6474.  37(5), s 1269- 1283 . doi: 10.1523/JNEUROSCI.2504-16.2016
• Hagen, Espen; Ness, Torbjørn; Khosrowshahi, Amir; Sørensen, Christina; Fyhn, Marianne; Hafting, Torkel; Franke, Felix & Einevoll, Gaute (2015). ViSAPy: A Python tool for biophysics-based generation of virtual spiking activity for evaluation of spike-sorting algorithms. Journal of Neuroscience Methods.  ISSN 0165-0270.  245, s 182- 204 . doi: 10.1016/j.jneumeth.2015.01.029
• Bonnevie, Tora; Dunn, Benjamin Adric; Fyhn, Marianne; Hafting, Torkel; Derdikman, Dori Moshe; Kubie, J. L.; Roudi, Yasser; Moser, Edvard Ingjald & Moser, May-Britt (2013). Grid cells require excitatory drive from the hippocampus. Nature Neuroscience.  ISSN 1097-6256.  16(3), s 309- 317 . doi: 10.1038/nn.3311
• Colgin, Laura Lee; Denninger, Tobias; Fyhn, Marianne; Hafting, Torkel; Bonnevie, Tora; Jensen, Ole; Moser, May-Britt & Moser, Edvard Ingjald (2009). Frequency of gamma oscillations routes flow of information in the hippocampus. Nature.  ISSN 0028-0836.  462(7271), s 353- U119 . doi: 10.1038/nature08573
• Derdikman, Dori Moshe; Whitlock, Jonathan; Tsao, Albert; Fyhn, Marianne; Hafting, Torkel; Moser, May-Britt & Moser, Edvard Ingjald (2009). Fragmentation of grid cell maps in a multicompartment environment. Nature Neuroscience.  ISSN 1097-6256.  12(10), s 1325- U155 . doi: 10.1038/nn.2396
• Fyhn, Marianne; Hafting, Torkel; Witter, Menno; Moser, Edvard Ingjald & Moser, May-Britt (2008). Grid cells in mice. Hippocampus.  ISSN 1050-9631.  18(12), s 1230- 1238 . doi: 10.1002/hipo.20472
• Hafting, Torkel; Fyhn, Marianne; Bonnevie, Tora; Moser, May-Britt & Moser, Edvard Ingjald (2008). Hippocampus-independent phase precession in entorhinal grid cells. Nature.  ISSN 0028-0836.  453, s 1248- U50 . doi: 10.1038/nature06957
• Kjelstrup, Kirsten Gjerstad; Solstad, Trygve; Brun, Vegard Heimly; Hafting, Torkel; Leutgeb, Stefan; Witter, Menno; Moser, Edvard Ingjald & Moser, May-Britt (2008). Finite scale of spatial representation in the hippocampus. Science.  ISSN 0036-8075.  321, s 140- 143 . doi: 10.1126/science.1157086
• Fyhn, Marianne; Hafting, Torkel; Treves, Alessandro; Moser, May-Britt & Moser, Edvard Ingjald (2007). Hippocampal remapping and grid realignment in entorhinal cortex. Nature.  ISSN 0028-0836.  446 . doi: 10.1038/nature05601
• Sargolini, Francesca; Fyhn, Marianne; Fyhn, Torkel Hafting; McNaughton, Bruce; Witter, Menno; Moser, May-Britt & Moser, Edvard Ingjald (2006). Conjunctive representation of position, direction, and velocity in entorhinal cortex. Science.  ISSN 0036-8075.  312
• Fyhn, Marianne & Hafting, Torkel (2006). "Gridceller" i hjernen danner et mentalt kart over omgivelsene. Det Kongelige Norske Videnskabers Selskab. Årbok.  ISSN 0803-1983.  s 47- 53
• Hafting, Torkel; Fyhn, Marianne; Molden, Sturla; Moser, May-Britt & Moser, Edvard Ingjald (2005). Microstructure of a spatial map in the entorhinal cortex. Nature.  ISSN 0028-0836.  436, s 801- 806

View all works in Cristin

• Aasebø, Ida Elisabeth Jørgensen; Røe, Malin Benum; Mobarhan, Milad; Lensjø, Kristian Kinden; Stöber, Tristan Manfred; Einevoll, Gaute; Hafting, Torkel & Fyhn, Marianne (2018). Orientation selectivity in the freely moving rat: Movement-robust orientation-selectivity (MROS) of units in the deep layers of the rat visual cortex.
• Dragly, Svenn-Arne; Mobarhan, Milad; Lepperød, Mikkel Elle; Tennøe, Simen; Stasik, Alexander Johannes; Fyhn, Marianne; Hafting, Torkel & Malthe-Sørenssen, Anders (2018). Exdir An alternative to HDF5 that uses Numpy files for data, YAML for metadata and simple directories to define the hierarchy.
• Hafting, Torkel (2018). Brain plasticity an perineuronal nets.
• Lensjø, Kristian Kinden; Rowlands, Daire; Dinh, Tovy; Thompson, Elise Holter; Andrews, Melissa; Hafting, Torkel; Fawcett, James; Dick, Gunnar & Fyhn, Marianne (2018). Conditional knock-out of the Acan gene removes perineuronal nets in adult mice and induces life-long brian plasticity.
• Røe, Malin Benum; Aasebø, Ida Elisabeth Jørgensen; Mobarhan, Milad; Lensjø, Kristian Kinden; Einevoll, Gaute; Hafting, Torkel & Fyhn, Marianne (2018). Movement-resistant orientation selectivity of cells in the deep layers of the rat visual cortex.
• Røe, Malin Benum; Aasebø, Ida Elisabeth Jørgensen; Mobarhan, Milad; Lensjø, Kristian Kinden; Einevoll, Gaute; Hafting, Torkel & Fyhn, Marianne (2018). Stable orientation tuning in the freely moving rat: Movement-robust orientation selective neurons in the deep layers of the primary visual cortex.
• Aasebø, Ida E. J.; Mobarhan, Milad; Røe, Malin Benum; Lensjø, Kristian Kinden; Einevoll, Gaute; Hafting, Torkel & Fyhn, Marianne (2017). Movement-resistant orientation-selective units in the deep layers of the visual cortex.
• Buccino, Alessio Paolo; Ness, Torbjørn Vefferstad; Einevoll, Gaute; Cauwenberghs, Gert; Fyhn, Marianne; Hafting, Torkel & Häfliger, Philipp (2017). Classification of Neural Cell-types from Extracellular Signatures on Multi-Electrode Arrays using Deep Learning.
• Christensen, Ane Charlotte; Fyhn, Marianne & Hafting, Torkel (2017). The role of perineuronal nets in spatial representations.
• Christensen, Ane Charlotte; Lensjø, Kristian Kinden; Lepperød, Mikkel Elle; Fyhn, Marianne & Hafting, Torkel (2017). The role of extracellular matrix molecules for spatial representations in medial entorhinal cortex.
• Dinh, Tovy; Lensjø, Kristian Kinden; Lanton, Rune Alexander; Dick, Gunnar; Fyhn, Marianne & Hafting, Torkel (2017). Increased ocular dominance plasticity in adult visual cortex after genetic knock out of aggrecan, an essential component of perineuronal nets.
• Dragly, Svenn-Arne; Mobarhan, Milad; Solbrå, Andreas Våvang; Tennøe, Simen; Hafreager, Anders; Malthe-Sørenssen, Anders; Fyhn, Marianne; Hafting, Torkel & Einevoll, Gaute (2017). Neuronify: An Educational Simulator for Neural Circuits. Show summary

  Neurons are cells in the brain that are able to rapidly change the electric field across their cell membrane. These changes allow neurons to communicate with each other and is the basis for the complex computations in the brain. Understanding how neurons communicate and the properties of neuronal networks is essential for neuroscience students. Traditionally, students draw networks with pen and paper and qualitatively deduce features of the network by analyzing the static drawings. Here, we present Neuronify, an app that allows students to draw the same networks on a computer or mobile device and run dynamic simulations without programming. The students can test their analysis by running the network and check their predictions against the outcome. Educational software (apps) can improve science education by providing an interactive way of learning about complicated topics that are hard to explain with text and static illustrations. Such software is readily available in many areas of natural science such as physics and electrical engineering. However, few educational apps are available for simulation of neural networks. Neuronify allows the user to easily create and explore neural networks in a plug-and-play simulation environment. The user can drag and drop network elements such as neurons, electrical stimulation tools and recording devices. The components can then easily be connected to one another. Building intuition for how neurons and neural networks behave has been a top priority in designing Neuronify. We aim to provide a low entry point to simulation-based neuroscience. Most undergraduate students do not have the computational experience to create their own neural simulator. Neuronify offers them an opportunity to build and experiment with neural networks in a graphical and easy-to-understand interface. By playing around with the networks, the students can develop a good understanding of their properties. To facilitate the use of Neuronify in teaching, a set of premade common network motifs is provided, performing functions such as input summation and detection of direction of stimulus movement. Neuronify is developed in C++ and QML using the cross-platform application framework Qt. It has been downloaded more than 30,000 times since its launch and is available on smart phones (Android, iOS), tablet computers as well personal computers (Windows, Mac, Linux).

• Lepperød, Mikkel Elle; Lai, Yi Ming; Fyhn, Marianne; Einevoll, Gaute; Solstad, Trygve; Hafting, Torkel & de Kamps, Marc (2017). Population density model of the entorhinal stellate-cell network with adaptation.
• Mobarhan, Milad; Halnes, Geir; Martínez-Cañada, Pablo; Hafting, Torkel; Fyhn, Marianne & Einevoll, Gaute (2017). Firing-rate Based Network Modeling of the dLGN Circuit: Effects of Cortical Feedback on Spatiotemporal Response Properties of Relay Cells.
• Thompson, Elise Holter; Lensjø, Kristian Kinden; Wigestrand, Mattis B; Hafting, Torkel; Malthe-Sørenssen, Anders & Fyhn, Marianne (2017). The perineuronal nets in the lateral secondary visual cortex are essential for remote visual fear memory.
• Bjerke, Line; Wigestrand, Mattis B; Aasebø, Ida E. J.; Fyhn, Marianne & Hafting, Torkel (2016). Inhibitory outputs from lateral hypothalamus to paraqueductal grey control innate defensive behavior.
• Blackstad, Jan Sigurd; Christensen, Ane Charlotte; Lensjø, Kristian Kinden; Hafting, Torkel & Fyhn, Marianne (2016). Involvement of perineuronal nets in spatial information transfer between the entorhinal cortex and hippocampus.
• Blackstad, Jan Sigurd; Christensen, Ane Charlotte; Lensjø, Kristian Kinden; Hafting, Torkel & Fyhn, Marianne (2016). Involvement of perineuronal nets in spatial information transfer between the entorhinal cortex and hippocampus.
• Hafting, Torkel (2016). Extracellular registration of neural activity in freely behaving animals.
• Hafting, Torkel (2016). From Science Fiction to Neuroscience.
• Hafting, Torkel (2016). Optogenetic dissection of neural circuits underlying defensive behaviours.
• Lensjø, Kristian Kinden; Lepperød, Mikkel Elle; Dick, Gunnar; Hafting, Torkel & Fyhn, Marianne (2016). Removal of perineuronal nets affects information processing and plasticity in the primary visual cortex.
• Lepperød, Mikkel Elle; Wigestrand, Mattis B; Frey, M.M.; Lensjø, Kristian Kinden; Einevoll, Gaute; Solstad, Trygve; Fyhn, Marianne & Hafting, Torkel (2016). Role of input-specific perturbations of medial septal projections to the grid cell network.
• Lepperød, Mikkel Elle; Wigestrand, Mattis B; Frey, Mina Martine; Lensjø, Kristian Kinden; Einevoll, Gaute; Solstad, Trygve; Fyhn, Marianne & Hafting, Torkel (2016). On the role of input-specific perturbations of medial septal projections to the grid cell network.
• Lepperød, Mikkel Elle; Wigestrand, Mattis B; Lensjø, Kristian Kinden; Frey, M.M.; Dragly, Svenn-Arne; Einevoll, Gaute; Solstad, Trygve; Fyhn, Marianne & Hafting, Torkel (2016). Grid cell network resilient to input-specific medial septum perturbations.
• Røe, Malin Benum; Aasebø, Ida E. J.; Lensjø, Kristian Kinden; Hafting, Torkel & Fyhn, Marianne (2016). Orientation selective cells in layer six of the primary visual cortex are resistant to the animal's movement.
• Thompson, Elise Holter; Lensjø, Kristian Kinden; Wigestrand, Mattis B; Hafting, Torkel & Fyhn, Marianne (2016). The perineuronal nets in the lateral secondary visual cortex and their impact on remote visual fear memory.
• Thompson, Elise Holter; Lensjø, Kristian Kinden; Wigestrand, Mattis B; Hafting, Torkel; Fyhn, Marianne & Malthe-Sørenssen, Anders (2016). The perineuronal nets in the lateral secondary visual cortex are essential for remote visual memory.
• Wigestrand, Mattis B; Aasebø, Ida E. J.; Tully, Annabelle; Dinh, Vy To; Lepperød, Mikkel Elle; Hafting, Torkel & Fyhn, Marianne (2016). Lateral hypothalamic outputs control innate defensive responses.
• Wigestrand, Mattis B; Aasebø, Ida E. J.; Tully, Annabelle; Lepperød, Mikkel Elle; Hafting, Torkel & Fyhn, Marianne (2016). Lateral hypothalamic outputs control innate defensive responses. Show summary

  When facing a threat, animals display defensive behaviors that are critical for survival. The hypothalamus is believed to mediate such defensive responses, but the prevailing view includes a medial/lateral separation, where medial hypothalamus is thought to influence defensive responses, while the lateral hypothalamic area (LHA) regulates feeding and arousal. Here we identify two distinct neural populations in the LHA with surprising survival functions in rats. The two neural populations, defined by their output projections to either the periaqueductal gray (PAG) or the lateral habenula (LHb) have distinct anatomical placements along the anterior-posterior axis of the LHA and express distinct biochemical markers. Optogenetic stimulation of the two LHA populations robustly induced opposite active- or passive defensive responses. Further, chemogenetic silencing of LHA and optogenetic silencing of the LHA-PAG projection disrupted innate defensive responses to a predator-like looming shadow. Using single-unit recordings in the downstream LHb and PAG, we show that the LHA-LHb projection is largely excitatory, while the LHA-PAG projection is mainly inhibitory. We are currently using a miniaturized microscope to image the calcium activity of the two LHA populations during threat processing in behaving rats. Overall, our findings identify a novel LHA circuit that is critical for appropriate defensive responses to innate visual threats. The location of the LHA defense circuits, intermingled within circuitry that governs feeding, suggests that this circuit may provide rapid cross-talk between circuits that govern foraging- and anti-predator behaviors.

• Aasebø, Ida E. J.; Hafting, Torkel; Maria, Stavrinou; Sandra, Nøkkevangen; Lepperød, Bjørn Mikkel Elle & Fyhn, Marianne (2015). Temporal processing in the visual cortex in the awake and anesthetized rat.
• Christensen, Ane Charlotte; Lensjø, Kristian Kinden; Lepperød, Bjørn Mikkel Elle; Fyhn, Marianne & Hafting, Torkel (2015). The role of extracellular matrix molecules for spatial representations and plasticity in entorhinal cortex.
• Hafting, Torkel (2015). Hjernens plastisitet.
• Hafting, Torkel (2015). The Nobel Prize in Physiology 2014 - neural representation of space.
• Hafting, Torkel (2015). The adaptive brain: Storage of long-term memories.
• Lensjø, Kristian Kinden; Lepperød, Bjørn Mikkel Elle; Dick, Gunnar; Hafting, Torkel & Fyhn, Marianne (2015). Removal of perineuronal nets in the visual cortex leads to a reduced inhibition and mimics critical period plasticity.
• Lepperød, Mikkel Elle; Lensjø, Kristian Kinden; Christensen, Ane Charlotte; Fyhn, Marianne; Hafting, Torkel & Einevoll, Gaute (2015). Building an entorhinal cortex network.
• Hafting, Torkel (2014). Hukommelse og læring - et innblikk i hvordan hjernen virker.
• Hafting, Torkel; Lensjø, Kristian Kinden; Christensen, Ane Charlotte; Dick, Gunnar & Fyhn, Marianne (2014). Perineuronal nets, plasticity and information-processing in visual cortex, medial entorhinal cortex and hippocampus..
• Aasebø, Ida E. J.; Norheim, Eivind Skjønsberg; Lensjø, Kristian Kinden; Fyhn, Marianne & Fyhn, Torkel Hafting (2013). The effect of anesthesia on activity and modulation of visually responsive neurons in cortical and subcortical areas.
• Hafting, Torkel (2013). Moderne nevrovitenskap - når science fiction blir virkelighet.
• Hagen, Espen; Ness, Torbjørn Bækø; Khosrowshahi, Amir; Sørensen, Christina; Fyhn, Marianne; Hafting, Torkel; Franke, Felix & Einevoll, Gaute Tomas (2013). Modeling of extracellular spike signatures.
• Hagen, Espen; Ness, Torbjørn Bækø; Khosrowshahi, Amir; Sørensen, Christina; Fyhn, Torkel Hafting; Franke, Felix & Einevoll, Gaute Tomas (2013). Generation of biophysically realistic model extracellular recordings for evaluation of spike sorting algorithms.
• Lensjø, Kristian Kinden; Dick, Gunnar; Fyhn, Torkel Hafting & Fyhn, Marianne (2013). Cortical processing in awake, behaving rats after removal of perineuronal nets.
• Fyhn, Marianne; Hafting, Torkel & Stryker, MP (2011). Long-term in vivo imaging of dendritic spines in layer II/III of visual cortex during the critical period. Show summary

  Acta Physiologica 2011; Volume 202, Supplement 685 :8.1.46

• Derdikman, Dori Moshe; Whitlock, JR; Tsao, Albert; Fyhn, Marianne; Hafting, Torkel; Moser, May-Britt & Moser, Edvard Ingjald (2009). Fragmentation of grid maps is influenced by geometry of the environement.
• Colgin, Laura Lee; Denninger, T; Fyhn, Marianne; Hafting, Torkel; Bonnevie, Tora; Jensen, O; Moser, May-Britt & Moser, Edvard Ingjald (2009). Frequency of gamma oscillations routes flow of information in the hippocampus.
• Kjelstrup, K.B; Brun, V.H; Solstad, Trygve; Hafting, Torkel; Leutgeb, Stefan; Fyhn, Marianne; Witter, Menno; Moser, May-Britt & Moser, Edvard Ingjald (2008). Spatial coding along the dorsal-to-ventral axis of the hippocampus and medial entorhinal cortex.
• canto, Cathrin Barbara; Kwag, J; Hafting, Torkel; Fyhn, Marianne; Mann, EO; Moser, Edvard Ingjald; Moser, May-Britt; Witter, Menno & Paulsen, Ole (2007). Rate-to-phase transformation in layer II principal neurons of the rat medial entorhinal cortex. Society for Neuroscience : Abstracts.  33
• Fyhn, Marianne; Hafting, Torkel; Witter, Menno; Moser, Edvard Ingjald & Moser, May-Britt (2007). Grid cells in medial entorhinal cortex of mice. Society for Neuroscience : Abstracts.  33
• Kjelstrup, Kirsten Gjerstad; Solstad, Trygve; Brun, Vegard Heimly; Hafting, Torkel; Fyhn, Marianne; Leutgeb, Stefan; Moser, Edvard Ingjald; Moser, May-Britt & Witter, Menno (2007). Very large place fields at the ventral pole of the hippocampal CA3 area. Abstracts - Society for Neuroscience.  ISSN 0190-5295.  33
• Colgin, Laura Lee; Fyhn, Marianne; Hafting, Torkel; Jensen, Ole; Moser, Edvard Ingjald & Moser, May-Britt (2007). Medial entorhinal cortex and CA3 synchronize with fast and slow gamma rhythms in CA. Society for Neuroscience : Abstracts.  33
• Hafting, Torkel (2007). Hjerneceller som danner kart over omgivelsene.
• Hafting, Torkel (2007). Interactions between entorhinal grid cells and hippocampal place cells. Show summary

  In the medial entorhinal cortex (MEC) neurons with positional, directional, and metric information constitutes a context- independent spatial map of the environment. The hippocampal place code is context specific and responds to changes in the sensory or motivational input as either a full reorganization of the place code (global remapping), or as a selective change of firing rates (rate remapping). To determine whether the hippocampal population response originates within the hippocampus or upstream in the grid-cell network of the MEC, we recorded spike activity in these areas under conditions that gave either global or rate remapping in the hippocampus. Global remapping in CA3 was always accompanied by a coherent offset in the grid of simultaneously recorded MEC neurons. The strong temporal contiguity of hippocampal remapping and entorhinal grid shifts suggests that the two phenomena are mechanistically related. During rate remapping in CA3, grid cells inMEC showed no offset or rotation, and the firing rate distribution remained unaltered. Thus, it is likely that rate remapping is of intrahippocampal origin. The entorhinal cortex and hippocampus have reciprocal connections suggesting an integrated unit with bidirectional influence. It has been suggested that stored representations in the hippocampus anchor the grid to the environment. Temporal inactivation of the hippocampus by local infusion of muscimol dramatically reduced the firing frequency of grid cells, and the grid patterns almost vanished from the time-averaged rate maps, while simultaneously recorded head-direction cells from layer III were not affected. These results suggest that entorhinal grid fields are dependent on functional interactions with the hippocampus. It remains to be elucidated, however, whether the hippocampal output exerts a general excitatory drive on the grid cells or if grid stability depends on stored representations in the hippocampus.

• Hafting, Torkel; Fyhn, Marianne; Moser, Edvard Ingjald & Moser, May-Britt (2007). Experience-dependent backward shift of entorhinal grid fields. Society for Neuroscience : Abstracts.  33
• Hafting, Torkel (2006). Hukommelse og stedsans - hjerneceller som danner mentale kart.
• Kjelstrup, Kirsten Brun; Solstad, Trygve; Brun, Vegard Heimly; Fyhn, Marianne; Hafting, Torkel; Leutgeb, Stefan; Witter, Menno; Moser, Edvard Ingjald & Moser, May-Britt (2006). Spatial scale expansion along dorsal-to-ventral axis of hippocampal area CA3 in the rat.
• Sargolini, Francesca; Fyhn, Marianne; Hafting, Torkel; McNaughton, Bruce; Witter, Menno; Moser, Edvard Ingjald & Moser, May-Britt (2006). Integration of position, direction and velocity information in the medial entorhinal cortex.
• Sargolini, Francesca; Fyhn, Marianne; Hafting, Torkel; McNaughton, Bruce; Witter, Menno; Moser, May-Britt & Moser, Edvard Ingjald (2006). Spatial navigation and entorhinal grid cells. Chemical Senses.  ISSN 0379-864X.  31, s E24- E24
• Bonnevie, Tora; Fyhn, Marianne; Hafting, Torkel; Moser, Edvard Ingjald & Moser, May-Britt (2006). Misalignment of entorhinal grid fields after hippocampal inactivation.
• Derdikman, Dori Moshe; Fyhn, Marianne; Hafting, Torkel; Moser, May-Britt & Moser, Edvard Ingjald (2006). Breaking up the entorhinal grid in a hairpin maze.
• Fyhn, Marianne; Hafting, Torkel; Moser, May-Britt & Moser, Edvard Ingjald (2006). Theta modulation and phase precession in grid cells in the medical entorhinal cortex.
• Fyhn, Marianne; Hafting, Torkel; Treves, Alessandro; Moser, Edvard Ingjald & Moser, May-Britt (2006). Coherence in ensembles of entorhinal grid cells.
• Hafting, Torkel; Fyhn, Marianne; Treves, Alessandro; Moser, Edvard Ingjald & Moser, May-Britt (2006). Coherent realignment of entorhinal grid cells coincides global remapping in the hippocampus.
• Hafting, Torkel (2005). Grid cells and head direction cells in entorhinal cortex.
• Fyhn, Torkel Hafting; Fyhn, Marianne; Moser, Edvard Ingjald & Moser, May-Britt (2004). Mnemonic propeties of position-modulated neurons in dorsocaudal medial entorhinal cortex. Society for Neuroscience : Abstracts.  30
• Fyhn, Marianne; Fyhn, Torkel Hafting; Treves, Alessandro; Moser, May-Britt & Moser, Edvard Ingjald (2004). Pattern separation in hippocampus but not layers II and III of entorhinal cortex. Society for Neuroscience : Abstracts.  30
• Otnæss, Mona; Hafting, Torkel; Tuvnes, Frode Alexander; Molden, Sturla; Moser, Edvard Ingjald & Moser, May-Britt (2004). Does the hippocampus contribute to simple non – spatial associations?.

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