substantia nigra


Also found in: Dictionary, Thesaurus, Acronyms, Wikipedia.
Related to substantia nigra: dopamine, Cranial nerves, basal ganglia, striatum

substantia

 [sub-stan´she-ah] (L.)
substance; used in anatomic nomenclature in naming various components of body tissues or structures.
substantia al´ba white matter.
substantia gelatino´sa the substance sheathing the posterior horn of the spinal cord and lining its central canal.
substantia gri´sea gray matter.
substantia ni´gra a dark layer of gray matter separating the tegmentum of the midbrain from the crus cerebri.

sub·stan·ti·a ni'g·ra

[TA]
a large cell mass, crescentic on transverse section, extending forward over the inner surface of the crus cerebri from the rostral border of the pons into the subthalamic region. It is composed of a dorsal stratum of closely spaced pigmented (that is, melanin-containing) cells, the pars compacta [TA]; a larger ventral region of widely scattered cells, the pars reticulata [TA]; and smaller less distinct regions, the pars lateralis [TA] and pars retrorubralis [TA]; the pars compacta in particular includes numerous cells that project forward to the striatum (caudate nucleus and putamen) and contain dopamine, which acts as the transmitter at their synaptic endings. Other, apparently nondopaminergic, cells of the substantia nigra project to a rostral part of the ventral nucleus of thalamus, to the middle layers of the superior colliculus, and to restricted parts of the reticular formation of the midbrain. The nigrostriatal projection is reciprocated by a massive striatonigral fiber system with multiple neurotransmitters, chief among which is γ-aminobutyric acid (GABA). The substantia nigra receives smaller afferent projections from the subthalamic nucleus, the lateral segment of the globus pallidus, the dorsal nucleus of the raphe, and the pedunculopontine nucleus of the midbrain. The pars reticulata forms part of the output system for the striate body. The substantia n. is involved in the metabolic disturbances associated with Parkinson disease and Huntington disease.

substantia nigra

(nī′grə, nĭg′rə)
n.
A layer of large pigmented nerve cells in the midbrain that produce dopamine and whose destruction is associated with Parkinson's disease.

substantia nigra

Etymology: L, substantia, essence, niger, black
a dark band of gray matter lying between the tegmentum of the midbrain and the crus cerebri.

sub·stan·ti·a nigra

(sŭb-stan'shē-ă nī'gră) [TA]
A large cell mass, crescentic on transverse section, extending forward over the dorsal surface of the crus cerebri from the rostral border of the pons into the subthalamic region; it is composed of a dorsal stratum of closely spaced pigmented (i.e., melanin-containing) cells, the pars compacta, and a larger ventral region of widely scattered cells, the pars reticulata. The substantia nigra is involved in the metabolic disturbances associated with parkinsonism and Huntington disease.

substantia nigra

A layer of grey matter (nerve cell bodies) containing pigmented nerve cells, that spreads throughout the white substance of the midbrain and receives fibres from the BASAL GANGLIA. DOPAMINE is produced in the substantia nigra, and loss of the pigment cells is a constant finding in PARKINSON'S DISEASE.

Substantia nigra

One of the movement control centers of the brain.
Mentioned in: Parkinson Disease

Soemmerring,

Samuel Thomas von, German anatomist, 1755-1830.
ring of Soemmerring - a mass of lenticular fibers enclosed between the anterior and posterior portion of the lenticular capsule, leaving the pupillary area relatively free.
Soemmerring ganglion - a large cell mass extending forward over the dorsal surface of the crus cerebri from the rostral border of the pons into the subthalamic region. Synonym(s): substantia nigra
Soemmerring ligament - small fibers attaching the lacrimal gland to the periorbita.
Soemmerring muscle - a fasciculus occasionally passing from the thyrohyoid muscle to the isthmus of the thyroid gland. Synonym(s): levator muscle of thyroid gland
Soemmerring spot - an oval area of the sensory retina at the center of which is the central fovea, which contains only retinal cones. Synonym(s): macula retinae

substantia nigra

part of extrapyramidal system (basal ganglia) governing normal motor control (see parkinsonism)

substantia nigra (sb·stanˑ·shē· nīˑ·gr),

n the portion of the mesencephalon (midbrain) whose degeneration is implicated in Parkinson's disease.
Enlarge picture
Substantia nigra.

substantia

pl. substantiae [L.] substance.

substantia alba
the white matter of the spinal cord and the brain.
substantia compacta
compact bone.
substantia gelatinosa
the substance sheathing the posterior horn of the spinal cord and lining its central canal.
substantia grisea
the gray matter of the spinal cord and brain.
substantia grisea centralis
the central gray matter that surrounds the cerebral aqueduct.
substantia nigra
the layer of gray substance separating the tegmentum of the midbrain from the crus cerebri.
substantia propria corneae
layer of transparent lamellated fibrous connective tissue which constitutes the bulk of the cornea; composed of collagen fibers disposed in platelike formations, fibroblasts and ground substance with many nerve fibers but no blood vessels.
substantia propria choroid
loose connective tissue of the choroid.
References in periodicals archive ?
The normal function of the globus pallidus and substantia nigra is to inhibit the thalamus; when the two structures are disinhibited, the thalamus sends increased excitatory impulses to the cortex, propagating excitation of motor neurons.
Hence, the degree of Parkinsonism is associated with pathology in the striatum and especially the putamen and the substantia nigra.
Right-unilateral lesioning of the substantia nigra was performed by stereotaxic microinjections of 8 micrograms (free base) 6-OHDA, dissolved in 4 [micro]l physiological saline containing 0.
These early symptoms aren't specific enough for a definitive diagnosis, but they hint that the disease may begin in regions of the brain other than the substantia nigra, Eidelberg says.
In this time interval, the previously visualized linear diffusion abnormality in the substantia nigra had progressed to a hyperintense signal on FLAIR (Figure 2), most likely representing edema, and on T1 images (Figure 3), as a likely consequence of the development of bilateral substantia nigra hemorrhages.
Symptoms of Parkinson's disease can be traced to the progressive death of nerve cells in an area of the brain called the substantia nigra.
A magnetic resonance imaging (MRI) scan of the brain showed a striking signal change on T2 in the substantia nigra of the midbrain, mainly at the right side.
Certain cells in the substantia nigra use dopamine as their neurotransmitter.
Bayne: The area of the brain called the substantia nigra starts to die.
Parkinson's disease is a devastating neurologic disorder that occurs when neurons degenerate in the region of the midbrain called the substantia nigra.
Researchers believe that Parkinson's is caused by the destruction of cells in various parts of the brain, including the substantia nigra, where dopamine is produced.
OTCQB:AMBS), a biotechnology company focused on developing therapeutic and diagnostic products for neurological disorders and orphan indications, announced late last week that it has completed a study of mesencephalic-astrocyte-derived neurotrophic factor (MANF) administration to the putamen and the substantia nigra of pigs by convection-enhanced delivery.

Full browser ?