The entorhinal cortex (EC) is an area of the brain's allocortex, located in the medial temporal lobe, whose functions include being a widespread network hub for memory, navigation, and the perception of time. The EC is the main interface between the hippocampus and neocortex. The EC-hippocampus system plays an important role in declarative (autobiographical/episodic/semantic) memories and in particular spatial memories including memory formation, memory consolidation, and memory optimization in sleep. The EC is also responsible for the pre-processing (familiarity) of the input signals in the reflex nictitating membrane response of classical trace conditioning; the association of impulses from the eye and the ear occurs in the entorhinal cortex.
The dentate gyrus (DG) is part of the hippocampal formation in the temporal lobe of the brain, which also includes the hippocampus and the subiculum. The dentate gyrus is part of the hippocampal trisynaptic circuit and is thought to contribute to the formation of new episodic memories, the spontaneous exploration of novel environments and other functions.
In cognitive psychology and neuroscience, spatial memory is a form of memory responsible for the recording and recovery of information needed to plan a course to a location and to recall the location of an object or the occurrence of an event. Spatial memory is necessary for orientation in space. Spatial memory can also be divided into egocentric and allocentric spatial memory. A person's spatial memory is required to navigate around a familiar city. A rat's spatial memory is needed to learn the location of food at the end of a maze. In both humans and animals, spatial memories are summarized as a cognitive map.
A place cell is a kind of pyramidal neuron in the hippocampus that becomes active when an animal enters a particular place in its environment, which is known as the place field. Place cells are thought to act collectively as a cognitive representation of a specific location in space, known as a cognitive map. Place cells work with other types of neurons in the hippocampus and surrounding regions to perform this kind of spatial processing. They have been found in a variety of animals, including rodents, bats, monkeys and humans.
A cognitive map is a type of mental representation which serves an individual to acquire, code, store, recall, and decode information about the relative locations and attributes of phenomena in their everyday or metaphorical spatial environment. The concept was introduced by Edward Tolman in 1948. He tried to explain the behavior of rats that appeared to learn the spatial layout of a maze, and subsequently the concept was applied to other animals, including humans. The term was later generalized by some researchers, especially in the field of operations research, to refer to a kind of semantic network representing an individual's personal knowledge or schemas.
The subiculum is the most inferior component of the hippocampal formation. It lies between the entorhinal cortex and the CA1 subfield of the hippocampus proper.
The hippocampal formation is a compound structure in the medial temporal lobe of the brain. It forms a c-shaped bulge on the floor of the temporal horn of the lateral ventricle. There is no consensus concerning which brain regions are encompassed by the term, with some authors defining it as the dentate gyrus, the hippocampus proper and the subiculum; and others including also the presubiculum, parasubiculum, and entorhinal cortex. The hippocampal formation is thought to play a role in memory, spatial navigation and control of attention. The neural layout and pathways within the hippocampal formation are very similar in all mammals.
A grid cell is a type of neuron within the entorhinal cortex that fires at regular intervals as an animal navigates an open area, allowing it to understand its position in space by storing and integrating information about location, distance, and direction. Grid cells have been found in many animals, including rats, mice, bats, monkeys, and humans.
Michael Hasselmo is an American neuroscientist and professor in the Department of Psychological and Brain Sciences at Boston University. He is the director of the Center for Systems Neuroscience and is editor-in-chief of Hippocampus (journal). Hasselmo studies oscillatory dynamics and neuromodulatory regulation in cortical mechanisms for memory guided behavior and spatial navigation using a combination of neurophysiological and behavioral experiments in conjunction with computational modeling. In addition to his peer-reviewed publications, Hasselmo wrote the book How We Remember: Brain Mechanisms of Episodic Memory.
The Moser research environment is the informal name of a research environment established and led by the Nobel laureates Edvard Moser and May-Britt Moser at the Norwegian University of Science and Technology (NTNU) in Trondheim, Norway. The Mosers joined the university as professors of psychology in 1996, and formed their own neuroscience research group. The research group eventually evolved into several projects and research centers. The Mosers were awarded the 2014 Nobel Prize in Physiology or Medicine "for their discoveries of cells that constitute a positioning system in the brain."
Boundary cells are neurons found in the hippocampal formation that respond to the presence of an environmental boundary at a particular distance and direction from an animal. The existence of cells with these firing characteristics were first predicted on the basis of properties of place cells. Boundary cells were subsequently discovered in several regions of the hippocampal formation: the subiculum, presubiculum and entorhinal cortex.
Edvard Ingjald Moser is a Norwegian psychologist and neuroscientist, who is a professor at the Norwegian University of Science and Technology (NTNU) in Trondheim. In 2005, he and his then-wife May-Britt Moser discovered grid cells in the brain's medial entorhinal cortex. Grid cells are specialized neurons that provide the brain with a coordinate system and a metric for space. In 2018, he discovered a neural network that expresses a person's sense of time in experiences and memories located in the brain's lateral entorhinal cortex.
John O'Keefe, is an American-British neuroscientist, psychologist and a professor at the Sainsbury Wellcome Centre for Neural Circuits and Behaviour and the Research Department of Cell and Developmental Biology at University College London. He discovered place cells in the hippocampus, and that they show a specific kind of temporal coding in the form of theta phase precession. He shared the Nobel Prize in Physiology or Medicine in 2014, together with May-Britt Moser and Edvard Moser; he has received several other awards. He has worked at University College London for his entire career, but also held a part-time chair at the Norwegian University of Science and Technology at the behest of his Norwegian collaborators, the Mosers.
Speed cells are neurons whose firing rates depend on an animal's speed through its environment. Together with place cells, grid cells, boundary cells, and head direction cells, they form a part of a larger set of neurons that are involved in cognitive mapping of the surrounding environment. Speed cells are found in the entorhinal cortex.
The Department of Psychology at the University of Oslo is the oldest and largest research institute and educational institution in psychology in Norway. It is Norway's main research institution in clinical psychology, cognitive psychology, developmental psychology, personality psychology, and social and cultural psychology, and one of the main research environments in neuroscience. The institute is located in the Harald Schjelderup Building adjacent to Oslo University Hospital, Rikshospitalet in the Gaustad area of Oslo; the building is shared with parts of the Faculty of Medicine, while Oslo University Hospital occupies surrounding buildings. The institute's alumni include two Nobel laureates, Edvard Moser and May-Britt Moser.
Phase precession is a neurophysiological process in which the time of firing of action potentials by individual neurons occurs progressively earlier in relation to the phase of the local field potential oscillation with each successive cycle. In place cells, a type of neuron found in the hippocampal region of the brain, phase precession is believed to play a major role in the neural coding of information. John O'Keefe, who later shared the 2014 Nobel Prize in Physiology or Medicine for his discovery that place cells help form a "map" of the body's position in space, co-discovered phase precession with Michael Recce in 1993.
Audrey van der Meer is a Dutch-born Norwegian neuroscientist and Professor of Neuropsychology at the Department of Psychology at the Norwegian University of Science and Technology (NTNU). With her husband, Professor of Cognitive Psychology Ruud van der Weel, she directs the Developmental Neuroscience Laboratory at NTNU. Her research seeks to understand the underlying principles that guide development, learning, and cognitive ageing. She joined the psychology department at NTNU in 1996, in the same year fellow neuroscientists Edvard Moser and May-Britt Moser joined the department; in 1997 she was promoted to full professor of neuroscience. She was part of the Section for Biological Psychology headed by Edvard Moser, but had her own research group. She is a member of the Royal Norwegian Society of Sciences and Letters.
Kathryn Jane Jeffery is a neuroscientist from New Zealand. She is a professor of behavioural neuroscience at University College London. She studies how the brain encodes three-dimensional and complex space, and the role of this representation in spatial cognition and navigation.
Lisa Giocomo is an American neuroscientist who is a Professor in the Department of Neurobiology at Stanford University School of Medicine. Giocomo probes the molecular and cellular mechanisms underlying cortical neural circuits involved in spatial navigation and memory.
Ole Jensen is a Danish neuroscientist and professor of translational neuroscience at the School of Psychology, University of Birmingham. He is known for his research work on applying magnetoencephalography to study the functioning of human brain.
