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1. 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.

1. 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.

1. 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.

1. 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.

1. 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.

1. 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.

1. Glossary

Norepinephrine

Along with dopamine and adrenaline, norepinephrine (NE) or sometimes noradrenaline (NA)belongs to the catecholamines. It is produced in cells of the locus coeruleus and in the adrenal medulla and usually has a stimulating effect. Noradrenaline is often associated with stress.

1. Glossary

Nociceptor

Nociceptors are the pain receptors in the body. They respond to sharp stimuli, heat, or chemical stimuli such as acid. In other words, they respond to imminent or actual tissue damage. Noxiceptors are found in almost all tissues in the human body – with one important exception: the brain itself, whose nerve tissue does not contain any noxiceptors.

1. Glossary

Anterior nuclei

This anterior, or front, core group of the thalamus maintains fiber connections with limbic areas, especially the hippocampus and the cingulate gyrus. It is considered an important hub of the limbic system.

1. Glossary

Medial nuclei

The medial thalamic nuclei, especially the mediodorsal nucleus, are located in the medial thalamus and are closely connected to the prefrontal cortex and the limbic system. They are primarily responsible for higher cognitive functions such as planning, attention, and working memory, but are also involved in processing emotions and motivation. In addition, they integrate complex information from different areas of the brain.