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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The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

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

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

diencephalon

[¦dī·en′sef·ə‚län]
(embryology)
The posterior division of the embryonic forebrain in vertebrates.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
The pineal body appeared inverted tubal structure with an obtuse triangle bottom about 6.93 mm in length and 6.40 mm in width, it originated from diencephalon the tubal part is pass between the cerebrum and cerebellum, it bottom settle in the central part of the transverse fissure (Fig.
It suspended from the ventral surface of the brain by the infundibulum that was about 4.25 mm in length and 3.48 mm in width, which defined as hallow tube like structure connect hypothalamus with hypophysis, the hypophysis is related to the diencephalon region ventrally at the level of optic lobe.
Midbrain presented caudal to the diencephalon definitely to the hypothalamus and hypophysis and no line of demarcation between them (diencephalon and mesencephalon).
We focused on the tadpole diencephalon (preoptic/hypothalamic area) because the gene expression program for neural development of this brain region has been characterized (23).
After the 10-day exposure, tadpoles from experiment 1 were anesthetized using MS222 (Sigma), and the diencephalon, which contains the developing preoptic/hypothalamic area, was rapidly dissected and frozen on dry ice for subsequent isolation of poly [(A).sup.+]RNA.