midbrain


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Related to midbrain: Midbrain tegmentum

mesencephalon

 [mes″en-sef´ah-lon]
1. the short part of the brainstem just above the pons; it contains the nerve pathways between the cerebral hemispheres and the medulla oblongata, as well as nuclei (relay stations or centers) of the third and fourth cranial nerves. The center for visual reflexes, such as moving the head and eyes, is located here.
The mesencephalon (midbrain). From Applegate, 2000.
2. the middle of the three primary brain vesicles of the embryo; called also midbrain. adj., adj mesencephal´ic.

mes·en·ceph·a·lon

(mes-en-sef'ă-lon), [TA]
That part of the brainstem developing from the middle of the three primary cerebral vesicles of the embryo (the caudal of these being the rhombencephalon or hindbrain, the rostral the prosencephalon or forebrain). In the adult, the mesencephalon is characterized by the unique conformation of its roof plate, the lamina tecti (tectal plate [TA] or quadrigeminal plate [TAalt]). composed of the bilaterally paired superior and inferior colliculus, and by the massive paired prominence of the crus cerebri at its anterolateral (ventrolateral) surface. On transverse section, its patent central canal, the cerebral aqueduct, is surrounded by a prominent ring of gray matter poor in myelinated fibers; the periaqueductal gray is adjoined by the myelin-rich mesencephalic tegmentum, and covered posteriorly (dorsally) by the mesencephalic tectal plate. Prominent cell groups of the mesencephalon include the motor nuclei of the trochlear and oculomotor nerves, the red nucleus, and the substantia nigra.
Synonym(s): midbrain vesicle ☆ , midbrain
[mes- + G. enkephalos, brain]

midbrain

The part of the brain stem located below the cerebral cortex (joining the diencephalon (thalamus and hypothalamus)) and above the hindbrain (arising from the pons/metencephalon).

Components
Tectum/corpora quadrigemina, tegmentum, cerebral aqueduct, cerebral peduncles, substantia nigra, various nuclei and fasciculi.

Functions
Associated with motor pathways via the basal ganglia; motivation and habituation via dopaminergic pathways via substantia nigra; helps relay information for vision and hearing.

mes·en·ceph·a·lon

(mes'en-sef'ă-lon) [TA]
That part of the brainstem developing from the middle of the three primary cerebral vesicles of the embryo. In an adult, the mesencephalon is characterized by the unique conformation of its roof plate, the lamina of the mesencephalic tectum, composed of the bilaterally paired superior and inferior colliculi, and by the massive paired prominence of the crus cerebri at its ventral surface. Prominent cell groups of the mesencephalon include the motor nuclei of the trochlear and oculomotor nerves, the red nucleus, and the substantia nigra.
Synonym(s): midbrain.
[G. mes- middle + G. enkephalos, brain]

midbrain

or

mesencephalon

that part of the brain lying between the forebrain and hindbrain. It contains the optic lobe and is particularly concerned with hearing and sight. see FOREBRAIN, HINDBRAIN.

mes·en·ceph·a·lon

(mes'en-sef'ă-lon) [TA]
That part of the brainstem developing from the middle of the three primary cerebral vesicles of the embryo. In an adult, the mesencephalon is characterized by the unique conformation of its roof plate, the lamina of the mesencephalic tectum, composed of the bilaterally paired superior and inferior colliculi, and by the massive paired prominence of the crus cerebri at its ventral surface.
Synonym(s): midbrain.
[G. mes- middle + G. enkephalos, brain]
References in periodicals archive ?
In case of marked hypoplasia of a single P1 arterial segment or its complete absence (full FPCA), TPAs originate from the contralateral side and cross the midline to supply the medial aspects of both thalami and the rostral midbrain (Table 2 and Figure 2).
Midbrain DA neurons differentiated from hiPSCs upon transplantation into the adult brain were able to improve the behavioral phenotype of rats affected by PD [59].
It is possible that the calcified deposit in midbrain may be associated with the oculomotor disturbance.
To examine the links between the GR pathway and these two separate metals, we further assessed the toxicity of iAs or Cd in midbrain MM culture, an established method to assess the effects of developmental toxicants (L'Huillier et al.
Primary traumatic benign midbrain haematoma in hyperextension injuries of the head.
Emergency MRI was performed and showed enlargement of the lesion in the thalamus and additional cuneate fresh stroke on the right paramedian portion of the midbrain and small spotty fresh stroke on the left paramedian portion.
"We discovered that disrupting maternal care of mice produces changes in levels of hundreds of genes in the Ventral Tegmental Area (VTA), neurons located close to the midline on the floor of the midbrain, that primes this brain region to be in a depression-like state, even before we detect behavioural changes.
The current conventional understanding of brain evolution among vertebrates proposes that current complex brains evolved from simple three-part brains comprising of a forebrain, a midbrain and a hindbrain.
Scientists at the Luxembourg Centre for Systems Biomedicine (LCSB) of the University of Luxembourg have now succeeded in turning human stem cells derived from skin samples into tiny, three-dimensional, brain-like cultures that behave very similarly to cells in the human midbrain.
It is fairly rare that midbrain infarction only manifests as isolated medial rectus nuclear palsy.[sup][1] Here, we provided such an uncommon case and discussed the possible etiology.