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- Glossary
Substantia nigra
A nucleus complex in the ventral mesencephalon that plays a central role in initiating and modulating movement. It appears dark due to neuromelanin. Its dopaminergic neurons project via the nigrostriatal pathways to the putamen and caudate nucleus. Failure of these neurons leads to the typical symptoms of Parkinson's disease.
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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
Subthalamic nucleus
Although the subthalamic nucleus is a nucleus of the subthalamus in the diencephalon, it is functionally closely integrated into the motor control of the basal ganglia. It plays a role in impulse control, movement control, and inhibition of unwanted movements. Damage to this nucleus can lead to temporary, uncontrolled, jerky movements of the extremities – known as ballism. Doctors have already achieved successful treatment outcomes in both obsessive-compulsive disorder and Parkinson's disease by artificially stimulating this region with a neuroimplant.
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- Glossary
Subthalamus
The subthalamus is an area of the diencephalon located ventrally below the thalamus. It includes the subthalamic nucleus, which functionally belongs to the basal ganglia network. The subthalamus plays an important role in the regulation and inhibition of movement sequences and in impulse control.
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- Glossary
Calcarine sulcus
Cerebral sulcus that divides the median, inwardly located portion of the occipital lobe.
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- Glossary
Superior temporal sulcus
The superior temporal sulcus is the uppermost groove of the temporal lobe and lies below the Sylvian fissure. It separates the superior temporal gyrus from the middle temporal gyrus. Functionally, this area is involved in auditory processes, language processing, and the perception of socially relevant information.
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- Glossary
Supplementary motor area
Area of the association motor cortex in the frontal lobe that is involved in movement planning and the organization of movement sequences.
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- Glossary
Sympathetic nervous system
Part of the autonomic nervous system, whereby the sympathetic nervous system primarily transmits excitatory impulses – in contrast to its counterpart, the parasympathetic nervous system. For example, the sympathetic nervous system activates respiration, the heart, and circulation, but it also affects the smooth muscles of all internal organs. The sympathetic nervous system uses the neurotransmitters acetylcholine and norepinephrine.
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- Glossary
Synapse
A synapse is a connection between two neurons and serves as a means of communication between them. It consists of a presynaptic region – the terminal button of the sender neuron – and a postsynaptic region – the region of the receiver neuron with its receptors. Between them lies the synaptic cleft.
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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).
