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- Glossary
Mesolimbic pathway
A system of neurons that use dopamine as a neurotransmitter and play a crucial role in emotion, reward, and substance abuse. The cell bodies are located in the subtegmental area and extend to the amygdala, the hippocampus, and – most importantly – the nucleus accumbens, where they have their terminal buttons.
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- Glossary
Parkinson's disease
Parkinson's disease is one of the most common neurological disorders, caused by the death of dopamine-producing neurons in the substantia nigra, leading to a neurotransmitter imbalance in the basal ganglia. Symptoms usually begin late in life with mild tremors (resting tremor), increasing stiffness of the limbs, and slowed voluntary movements (bradykinesia). Later, postural instability, balance disorders, and difficulty walking occur. Other typical features include rigid facial expressions (hypomimia), a shuffling gait, and muscle stiffness (rigor). The disease is incurable, but its symptoms can be treated with medication (e.g., L-dopa, dopamine agonists) or surgery involving deep brain stimulation (brain pacemaker).
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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
Basal nucleus
A collection of nerve cells in the basal region of the telencephalon. The basal ganglia are considered to be an important producer of the neurotransmitter acetylcholine. In Alzheimer's patients and, in some cases, Parkinson's patients, the basal ganglia degenerate. As a result, they produce less and less acetylcholine, which neurologists associate with some of the symptoms of these diseases.
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- Glossary
Receptor
A receptor is a protein, usually located in the cell membrane or inside the cell, that recognizes a specific external signal (e.g., a neurotransmitter, hormone, or other ligand) and causes the cell to trigger a defined response. Depending on the type of receptor, this response can be excitatory, inhibitory, or modulatory.
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- Glossary
Serotonin
A neurotransmitter that acts as a messenger in the transmission of information between neurons at their synapses. It is primarily produced in the raphe nuclei of the brain stem and plays a key role in sleep and alertness, as well as emotional well-being.
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- Glossary
Substance P
Substance P is a neuropeptide that acts as a neurotransmitter and belongs to the tachykinin family. High concentrations are found in the dorsal horn of the spinal cord, where it is involved in pain modulation.
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- Glossary
Synaptic depression
Weakening of signal transmission at a synapse due to reduced neurotransmitter release or decreased receptor sensitivity; occurs, for example, with repeated stimulation (habituation).
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- Glossary
Tuber cinereum
The tuber cinereum is a hill-shaped area in the hypothalamus from which the infundibulum, the pituitary stalk, originates. The tuber nuclei are located in the tuber cinereum, including the nucleus tuberomammillaris, which is the only region in the brain that uses histamine as a neurotransmitter.
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- Basics
- Anatomy
The Mesencephalon
Important neurotransmitters, an astonishing array of colors, and a water pipe – that's the midbrain.
20.09.2025
