The hippocampus is a major component of the brain of humans and other vertebrates. Humans and other mammals have two hippocampi, one in each side of the brain. The hippocampus is part of the limbic system, and plays important roles in the consolidation of information from short-term memory to long-term memory, and in spatial memory that enables navigation. The hippocampus is located in the allocortex, with neural projections into the neocortex, in humans as well as other primates. The hippocampus, as the medial pallium, is a structure found in all vertebrates. In humans, it contains two main interlocking parts: the hippocampus proper, and the dentate gyrus.
A dendritic spine is a small membranous protrusion from a neuron's dendrite that typically receives input from a single axon at the synapse. Dendritic spines serve as a storage site for synaptic strength and help transmit electrical signals to the neuron's cell body. Most spines have a bulbous head, and a thin neck that connects the head of the spine to the shaft of the dendrite. The dendrites of a single neuron can contain hundreds to thousands of spines. In addition to spines providing an anatomical substrate for memory storage and synaptic transmission, they may also serve to increase the number of possible contacts between neurons. It has also been suggested that changes in the activity of neurons have a positive effect on spine morphology.
In neuroscience, long-term potentiation (LTP) is a persistent strengthening of synapses based on recent patterns of activity. These are patterns of synaptic activity that produce a long-lasting increase in signal transmission between two neurons. The opposite of LTP is long-term depression, which produces a long-lasting decrease in synaptic strength.
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.
Brain-derived neurotrophic factor (BDNF), or abrineurin, is a protein that, in humans, is encoded by the BDNF gene. BDNF is a member of the neurotrophin family of growth factors, which are related to the canonical nerve growth factor (NGF), a family which also includes NT-3 and NT-4/NT-5. Neurotrophic factors are found in the brain and the periphery. BDNF was first isolated from a pig brain in 1982 by Yves-Alain Barde and Hans Thoenen.
Brenda Milner is a British-Canadian neuropsychologist who has contributed extensively to the research literature on various topics in the field of clinical neuropsychology. Milner is a professor in the Department of Neurology and Neurosurgery at McGill University and a professor of Psychology at the Montreal Neurological Institute. As of 2020, she holds more than 25 honorary degrees and she continued to work in her nineties. Her current work covers many aspects of neuropsychology including her lifelong interest in the involvement of the temporal lobes in episodic memory. She is sometimes referred to as the founder of neuropsychology and has been essential in its development. She received the Balzan Prize for Cognitive Neuroscience in 2009, and the Kavli Prize in Neuroscience, together with John O'Keefe, and Marcus E. Raichle, in 2014. She turned 100 in July 2018 and at the time was still overseeing the work of researchers.
Pyramidal cells, or pyramidal neurons, are a type of multipolar neuron found in areas of the brain including the cerebral cortex, the hippocampus, and the amygdala. Pyramidal cells are the primary excitation units of the mammalian prefrontal cortex and the corticospinal tract. One of the main structural features of the pyramidal neuron is the conic shaped soma, or cell body, after which the neuron is named. Other key structural features of the pyramidal cell are a single axon, a large apical dendrite, multiple basal dendrites, and the presence of dendritic spines.
Synaptogenesis is the formation of synapses between neurons in the nervous system. Although it occurs throughout a healthy person's lifespan, an explosion of synapse formation occurs during early brain development, known as exuberant synaptogenesis. Synaptogenesis is particularly important during an individual's critical period, during which there is a certain degree of synaptic pruning due to competition for neural growth factors by neurons and synapses. Processes that are not used, or inhibited during their critical period will fail to develop normally later on in life.
Elizabeth Gould is an American neuroscientist and the Dorman T. Warren Professor of Psychology at Princeton University. She was an early investigator of adult neurogenesis in the hippocampus, a research area that continues to be controversial. In November 2002, Discover magazine listed her as one of the 50 most important women scientists.
Bruce Sherman McEwen was an American neuroendocrinologist and head of the Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology at Rockefeller University. He was known for his work on the effects of environmental and psychological stress, having coined the term allostatic load.
Kalirin, also known as Huntingtin-associated protein-interacting protein (HAPIP), protein duo (DUO), or serine/threonine-protein kinase with Dbl- and pleckstrin homology domain, is a protein that in humans is encoded by the KALRN gene. Kalirin was first identified in 1997 as a protein interacting with huntingtin-associated protein 1. Is also known to play an important role in nerve growth and axonal development.
The spine apparatus (SA) is a specialized form of endoplasmic reticulum (ER) that is found in a subpopulation of dendritic spines in central neurons. It was discovered by Edward George Gray in 1959 when he applied electron microscopy to fixed cortical tissue. The SA consists of a series of stacked discs that are connected to each other and to the dendritic system of ER-tubules. The actin binding protein synaptopodin is an essential component of the SA. Mice that lack the gene for synaptopodin do not form a spine apparatus. The SA is believed to play a role in synaptic plasticity, learning and memory, but the exact function of the spine apparatus is still enigmatic.
Neal J. Cohen is a professor of psychology in the Cognitive Neuroscience division of the University of Illinois at Urbana–Champaign. He is appointed as a full-time faculty member in the Beckman Institute for Advanced Science and Technology at the University of Illinois. He is the founding director of the Center for Nutrition, Learning, and Memory (CNLM), a partnership of the University of Illinois and Abbott Laboratories as of 2011. He is also the founding director of the Interdisciplinary Health Sciences Initiative (IHSI) at the University of Illinois, formed 2014.
Synaptic stabilization is crucial in the developing and adult nervous systems and is considered a result of the late phase of long-term potentiation (LTP). The mechanism involves strengthening and maintaining active synapses through increased expression of cytoskeletal and extracellular matrix elements and postsynaptic scaffold proteins, while pruning less active ones. For example, cell adhesion molecules (CAMs) play a large role in synaptic maintenance and stabilization. Gerald Edelman discovered CAMs and studied their function during development, which showed CAMs are required for cell migration and the formation of the entire nervous system. In the adult nervous system, CAMs play an integral role in synaptic plasticity relating to learning and memory.
Catherine S. Woolley is an American neuroendocrinologist. Woolley holds the William Deering Chair in Biological Sciences in the Department of Neurobiology, Weinberg College of Arts & Sciences, at Northwestern University. She is also a member of the Women's Health Research Institute in the Feinberg School of Medicine at Northwestern University.
Irene Mary Carmel Tracey is Vice-Chancellor of the University of Oxford and former Warden of Merton College, Oxford. She is also Professor of Anaesthetic Neuroscience in the Nuffield Department of Clinical Neurosciences and formerly Pro-Vice-Chancellor at the University of Oxford. She is a co-founder of the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), now the Wellcome Centre for Integrative Neuroimaging. Her team’s research is focused on the neuroscience of pain, specifically pain perception and analgesia as well as how anaesthetics produce altered states of consciousness. Her team uses multidisciplinary approaches including neuroimaging.
Brenda Bloodgood is an American neuroscientist and associate professor of neurobiology at the University of California, San Diego. Bloodgood studies the molecular and cellular basis of brain circuitry changes in response to an animal's interactions with the environment.
Cagla Eroglu is a Turkish neuroscientist and associate professor of cell biology and neurobiology at Duke University in Durham, North Carolina and an investigator with the Howard Hughes Medical Institute. Eroglu is also the director of graduate studies in cell and molecular biology at Duke University Medical Center. Eroglu is a leader in the field of glial biology, and her lab focuses on exploring the role of glial cells, specifically astrocytes, in synaptic development and connectivity.
Lauren Orefice is an American neuroscientist and assistant professor in the Department of Molecular Biology at Massachusetts General Hospital and in the Department of Genetics at Harvard Medical School. Orefice has made innovative discoveries about the role of peripheral nerves and sensory hypersensitivity in the development of Autism-like behaviors. Her research now focuses on exploring the basic biology of somatosensory neural circuits for both touch and gastrointestinal function in order to shed light on how peripheral sensation impacts brain development and susceptibility to diseases like Autism Spectrum Disorders.
Gina R. Poe is an American neuroscientist specializing in the study of sleep and its effect on memory and learning. Her findings have shown that the absence of noradrenaline and low levels of serotonin during sleep spindles allow the brain to form new memories during REM, as well as restructure old memory circuits to allow for more learning during later waking periods. She currently works as a professor at the University of California, Los Angeles (UCLA).
