A5086289649- Memory and Neural Mechanisms
- Neuroscience and Neuropharmacology Research
- Neural dynamics and brain function
- Neuroscience, Education and Cognitive Function
- Sleep and Wakefulness Research
- Photoreceptor and optogenetics research
- Neuroinflammation and Neurodegeneration Mechanisms
- Stress Responses and Cortisol
- Olfactory and Sensory Function Studies
- Memory Processes and Influences
- Neurogenesis and neuroplasticity mechanisms
- Zebrafish Biomedical Research Applications
- Anesthesia and Neurotoxicity Research
- Neuroscience and Neural Engineering
- Neuroendocrine regulation and behavior
- Spatial Cognition and Navigation
- Functional Brain Connectivity Studies
- Receptor Mechanisms and Signaling
- Axon Guidance and Neuronal Signaling
- Cell Image Analysis Techniques
- Innovative Teaching and Learning Methods
- Genetics, Bioinformatics, and Biomedical Research
- Neurotransmitter Receptor Influence on Behavior
- Educational and Psychological Assessments
- Science, Research, and Medicine
Norwegian University of Science and Technology
2016-2025
Norwegian Environment Agency
2017-2024
Kavli Institute for Systems Neuroscience
2007-2024
Médecins Sans Frontières
2024
Trondheim Kommune
2022
Freie Universität Berlin
2021
Charité - Universitätsmedizin Berlin
2021
Humboldt-Universität zu Berlin
2021
Einstein Center for Neurosciences Berlin
2021
The University of Texas at Austin
2018
Theoretical models have long pointed to the dentate gyrus as a possible source of neuronal pattern separation. In agreement with predictions from these models, we show that minimal changes in shape environment which rats are exploring can substantially alter correlated activity patterns among place-modulated granule cells gyrus. When environments made more different, new cell populations recruited CA3 but not These results imply dual mechanism for separation signals entorhinal cortex be...
Grid cells in the medial entorhinal cortex (MEC) are part of an environment-independent spatial coordinate system. To determine how information about location, direction, and distance is integrated grid-cell network, we recorded from each principal cell layer MEC rats that explored two-dimensional environments. Whereas II was predominated by grid cells, colocalized with head-direction conjunctive x deeper layers. All types were modulated running speed. The conjunction positional,...
As the interface between hippocampus and neocortex, entorhinal cortex is likely to play a pivotal role in memory. To determine how information represented this area, we measured spatial modulation of neural activity layers medial projecting hippocampus. Close postrhinal-entorhinal border, neurons had stable discrete multipeaked place fields, predicting rat's location as accurately cells Precise positional was not observed more ventromedially or upstream postrhinal cortex, suggesting that...
We report the existence of an entorhinal cell type that fires when animal is close to borders proximal environment. The orientation-specific edge-apposing activity these "border cells" maintained environment stretched and during testing in enclosures different size shape rooms. Border cells are relatively sparse, making up less than 10% local population, but can be found all layers medial cortex as well adjacent parasubiculum, often intermingled with head-direction grid cells. may...
Hippocampal neurons were recorded under conditions in which the recording chamber was varied but its location remained unchanged versus an identical encountered different places. Two forms of neuronal pattern separation occurred. In variable cue-constant place condition, firing rates active cells varied, often over more than order magnitude, whereas constant. place-constant cue both and changed, so that population vectors for a given statistically independent. These independent encoding...
We have determined the volume and location of hippocampal tissue required for normal acquisition a spatial memory task. Ibotenic acid was used to make bilateral symmetric lesions 20-100% volume. Even small transverse block (minislab) hippocampus (down 26% total) could support learning in water maze, provided it at septal (dorsal) pole hippocampus. Lesions pole, leaving 60% hippocampi intact, caused deficit, although electrophysiological responses, synaptic plasticity, preserved...
The hippocampus has a critical role in several fundamental memory operations, including the conditioning of fear to contextual information. We show that is necessary also for unconditioned fear, and involved circuitry at ventral pole hippocampus. Rats with selective hippocampal lesions failed avoid open arms an elevated plus-maze had decreased neuroendocrine stress responses during confinement brightly lit chamber. These effects were reproduced by half hippocampus, but not damage dorsal...
Measuring the dynamics of neural processing across time scales requires following spiking thousands individual neurons over milliseconds and months. To address this need, we introduce Neuropixels 2.0 probe together with newly designed analysis algorithms. The has more than 5000 sites is miniaturized to facilitate chronic implants in small mammals recording during unrestrained behavior. High-quality recordings long were reliably obtained mice rats six laboratories. Improved site density...
The hippocampus has differentiated into an extensively connected recurrent stage (CA3) followed by a feed-forward (CA1). We examined the function of this structural differentiation determining how cell ensembles in rat CA3 and CA1 generate representations rooms with common spatial elements. In CA3, distinct subsets pyramidal cells were activated each room, regardless similarity testing enclosure. CA1, populations overlapped, overlap increased similar enclosures. After exposure to novel...
To determine how spatial scale is represented in the pyramidal cell population of hippocampus, we recorded neural activity at multiple longitudinal levels this brain area while rats ran back and forth on an 18-meter-long linear track. CA3 cells had well-defined place fields all levels. The representation increased almost linearly from <1 meter dorsal pole to approximately 10 meters ventral pole. results suggest that place-cell map includes entire hippocampus environments are a...
In the adult brain, space and orientation are represented by an elaborate hippocampal-parahippocampal circuit consisting of head-direction cells, place grid cells. We report that a rudimentary map is already present when 2 1/2-week-old rat pups explore open environment outside nest for first time. Head-direction cells in pre- parasubiculum have adultlike properties from beginning. Place also but evolve more gradually. Grid show slowest development. The gradual refinement spatial...
Place cells in hippocampal area CA1 may receive positional information from the intrahippocampal associative network CA3 or directly entorhinal cortex. To determine whether direct connections support spatial firing and memory, we removed all input areas to CA1, thus isolating area. Pyramidal isolated developed sharp stable place fields. Rats with an showed normal acquisition of hippocampal-dependent recognition task. Spatial recall was impaired. These results suggest that hippocampus...