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- Glossary
Frontotemporal dementia
Frontotemporal dementia is a neurodegenerative disease. Unlike Alzheimer's dementia, Pick's disease usually begins before the age of 60 and initially manifests itself through changes in personality and social behavior. There are also variants that begin with speech disorders. In advanced stages, memory performance is also impaired. The physiological cause is degeneration of nerve cells in the frontal and temporal lobes of the brain. Similar to Alzheimer's disease, the aggregation of certain proteins appears to play a role in pathogenesis. However, doctors do not yet understand exactly what happens in this process and what other factors contribute to the development of Pick's disease. Today, classic Pick's disease is only a subtype of FTD in which characteristic Pick bodies can be detected in the brain.
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- Glossary
Functional magnetic resonance imaging
Functional magnetic resonance imaging (fMRI) is a modification of MRI that allows brain activity to be measured indirectly via regional blood flow and oxygen consumption. BOLD (blood oxygen level dependent) contrast is often used, which exploits differences in the magnetic behavior of oxygen-rich and oxygen-poor blood. An increase in the BOLD signal indicates increased neural activity. fMRI provides good spatial resolution and allows detailed conclusions to be drawn about the activity of specific areas of the brain, while the temporal resolution is in the range of seconds.
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Fear conditioning
The linking of a neutral stimulus to a stimulus that triggers fear – for example, first a soft sound, then a loud, frightening noise. After conditioning, the presentation of the neutral stimulus alone triggers fear.
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GABA
GABA is an amino acid and the most important inhibitory neurotransmitter, which acts as a messenger in the transmission of information between neurons at their synapses.
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Ganglion cell
The ganglion cell bundles the signals from the photoreceptors in the retina and transmits them via its axons (long, fiber-like extensions of a nerve cell. All of these axons together form the optic nerve.
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Ganglion
Term for a cluster of nerve cell bodies in the peripheral nervous system. The term nerve node is often used because of its appearance. (Greek gágglion = knot-like)
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Gap junction
A special connection between two cells that allows direct communication in the form of electrical cell coupling. Unlike most synapses, which use chemical messengers to transmit impulses, this connection is faster.
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Memory
Memory is a generic term for all types of information storage in the organism. In addition to pure retention, this also includes the absorption of information, its organization, and retrieval.
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- Glossary
Ossicles
The three bones located in the middle ear – the stapes, malleus, and incus – are known as the ossicles. These are the smallest bones in the human body. They mechanically transmit sound waves from the eardrum to the cochlea.
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- Glossary
Macula
The area of the retina with the highest density of photoreceptors. Due to this high "resolution," we see very sharply here. The diameter of the macula in humans is approximately 5 mm. The fovea centralis is located in the center of the macula.
