Diencephalon

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diencephalon

(dī'ənsĕf`əlŏn): see brainbrain,
the supervisory center of the nervous system in all vertebrates. It also serves as the site of emotions, memory, self-awareness, and thought. Anatomy and Function
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Diencephalon

 

the section of the brain that consists of the most anterior (in man, the topmost) part of the brain stem, over which the cerebral hemispheres are located.

Inferiorly and posteriorly, the diencephalon borders on the mesencephalon (midbrain). The central portion of the diencephalon, around which the other parts are grouped, is the thalamus. These other parts are the epithalamus, which includes the epiphysis; the hypothalamus, which is connected to the pituitary, or hypophysis; and the subthalamic nucleus. The formations of the diencephalon perform a number of very important functions: they participate in the organization of the body’s sensory processes (sensitivity), motor functions, and autonomic (visceral) activities. The diencephalon plays a very important role in processes related to emotional reactivity and the states of sleep and wakefulness, as well as in the autoregulatory processes of the brain, which are reflected in the overall electrical activity of its higher areas, as recorded in the electroencephalogram. The diencephalon processes and switches the currents of neural impulses that enter from the various sense organs and signal shifts in the body’s external and internal environments. It does the same with impulses from various brain structures and directs them to other areas of the brain, including the cerebral cortex.

L. P. LATASH


Diencephalon

 

the section of the brain at the base of the large hemispheres that is the extreme anterior part (in humans the superior part) of the brain stem. The different portions of the diencephalon are the thalamus, hypothalamus, and subthalamus. Together they have very important functions; for example, they participate in the organization of the sensory processes of brain analyzers and in the performance of autonomic functions. Other bodily functions they affect are sleep, memory, instinctive behavior, and emotional and motivational processes. The structures of the diencephalon are associated with the perception of pain sensations and with the integration of the processes that maintain homeostasis. The functions of the glands of internal secretion are regulated through releasing hormones (releasing factors) produced by the neurosecretory cells of the hypothalamus. Aldosterone is produced, for example, by the adrenal cortex with the participation of a special polypeptide from the hypothalamus.

L. P. LATASH

diencephalon

[¦dī·en′sef·ə‚län]
(embryology)
The posterior division of the embryonic forebrain in vertebrates.
References in periodicals archive ?
This same pattern of expression is also found in the same structures in humans, with the only difference in the MAOA expression in the amygdala and basal ganglia and in MAOB expression in diencephalic and midbrain structures.
A decrease in the number of GFP-labeled neurons was observed in the telencephalic (TC) and diencephalic (DC) clusters (Figure 1a,b,c,d) in embryos treated with ziram.
Regions of interest were evaluated on standardized axial mesencephalic and diencephalic planes.
The tenn "paroxysmal sympathetic hyperactivity" or PSH has been adapted and replaced previous terms used to describe the syndrome, such as episodic autonomic instability, dysautonomia, autonomic dysregulation, central autonomic dysfunction, paroxysmal autonomic instability with dystonia, sympathetic storming, autonomic storming, dysautonomic crises, and diencephalic fits (Baguley et al., 2014; Perkes, Menon, Nott, & Baguley, 2011).
The stage of diencephalic herniation may be mimicked by drugs, toxins, metabolic abnormalities as well as intra- and post-ictal states.
In most cadaveric dissection, Liliequist's membrane was composed of two distinct leaves: A diencephalic leaf directed toward the diencephalon (separated chiasmatic and interpeduncular cisterns) and a mesencephalic leaf directed toward the mesencephalon (separated interpeduncular and prepontine cisterns).
Implicit memory is moderated by a memory system with the exception of the medial-temporal diencephalic one that forms the foundation of explicit memory.
We considered that the fever was central with diencephalic implications.
Episodic diencephalic hypoperfusion in Kleine- Levin syndrome.
Diencephalic projections of the inferior colliculus (nucleus mesencephali lateralis, pars dorsalis).
The newly proposed criteria have been expanded to include six different core characteristics: optic neuritis; acute myelitis; area postrema syndrome (nausea, vomiting, and hiccups); other brain stem syndromes; symptomatic narcolepsy or acute diencephalic syndrome with MRI findings; and symptomatic cerebral syndrome with MRI findings.
These neurones started projecting axons ventrally pioneering the dorsoventral diencephalic tract (DVDT).