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- Glossary
Neurofibrils
Neurofibrils are fine fibrous structures in nerve cells that consist mainly of neurofilaments (a form of intermediate filaments) and other components of the cytoskeleton. They run in bundles through the cell body and the extensions of neurons and contribute significantly to the stabilization and shaping of the nerve cell. They appear as characteristic features of neurons even in the early embryo. Alzheimer's disease causes profound changes in cytoskeletal structures: the protein tau, which normally stabilizes microtubules, becomes excessively phosphorylated, detaches from the microtubules, and aggregates to form the typical neurofibrillary tangles (fibrillary bundles). These are a central pathological feature of the disease.
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- Glossary
Neurohypophysis
The neurohypophysis is the posterior lobe of the pituitary gland. It stores the hormones oxytocin and vasopressin, which are produced in the hypothalamus, and releases them into the bloodstream when needed.
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Neuromarketing
A relatively new, interdisciplinary field of research in market research that builds on the findings of neuroeconomics – and is not entirely without controversy. The concept of neuromarketing is based on the assumption that customers make purchasing decisions primarily on the basis of unconscious emotional reactions. Neuromarketing uses neurophysiological measurement methods to study these reactions in order to better understand how consumers respond to products, advertising, and sales environments – with the aim of influencing these responses and thus purchasing decisions at the point of sale (the store) through measures such as music or scents.
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- Glossary
Neuron
A neuron is a specialized cell in the nervous system that is responsible for processing and transmitting information. It receives signals via its dendrites and transmits them via its axon. Transmission occurs electrically within the neuron and, between neurons, usually chemically via synapses.
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- Glossary
Neural representation
Various parts of the brain contain representations not only of the sensory systems, but also of objects such as faces. For example, so-called place cells in the hippocampus appear to play an important role in the representation of space. Each place cell represents a specific location in the environment and becomes active when its owner is at that location. Another group of neurons, grid cells, fire in a regular hexagonal pattern that is interpreted as a metric grid of the environment. This grid provides a kind of coordinate system that place cells can use for location coding.
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- Glossary
Neuron doctrine
The neuron doctrine forms the basis for our current understanding of the nervous system. According to this doctrine, the brain does not consist of a single, interconnected nerve network, but rather of individual nerve cells that communicate with each other via contact points. This was discovered by the Spanish Ramon y Cajal at the end of the 19th century when he stained nerve cell preparations from chickens and mammals. He used a staining technique developed by Camillo Golgi. For their achievement, the two researchers – who were unfortunately at odds with each other – were awarded the Nobel Prize in Medicine in 1906.
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- Glossary
Neuroeconomics
Term for a field of research at the interface between neuroscience, economics, and psychology. The overarching goal of neuroeconomics is to understand how people make economic decisions. To this end, neuroeconomists investigate what happens in the brain during decision-making. They often use experimental setups from game theory, which usually involve winning or losing money. They examine the brains of their test subjects primarily using imaging techniques. Neuroeconomics is a young branch of research that is attracting great social interest.
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- Glossary
Neurotransmitter
A neurotransmitter is a chemical messenger, an intermediary substance. It is released by the sender neuron at the sites of cell-cell communication and has an excitatory or inhibitory effect on the receiver neuron.
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- Glossary
NMDA receptor
NMDA receptors are specialized receptor channels in the membrane of nerve cells that only open under very specific conditions. First, the neurotransmitter glutamate must bind to the receptor, and second, the receptor needs a cofactor such as glycine or D-serine. In addition, the postsynaptic cell membrane must be depolarized so that the magnesium ion (Mg²⁺) normally located in the channel pore is removed. If these conditions are met, an ion channel opens in the center of the receptor and allows calcium ions (Ca²⁺) in particular, but also sodium ions (Na⁺), to flow into the cell, while potassium ions (K⁺) flow out of the cell. The cell can respond to the influx of calcium in a variety of ways. NMDA receptors enable the brain to modify synaptic connections throughout life. They are crucial for forms of synaptic plasticity such as long-term potentiation (LTP) and long-term depression (LTD) and thus play a central role in the formation and storage of memory content.
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- Glossary
Non-declarative memory
Non-declarative memory is part of long-term memory. It encompasses automated behaviors, learned skills, and habits that usually occur unconsciously. In contrast to declarative memory, the contents of non-declarative memory are difficult or impossible to express verbally. Non-declarative memory includes procedural learning and priming, among other things.
