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 ?
The diencephalon develops into the epithalamus, thalamus, hypothalamus, globi pallidi, the pineal gland and the neurohypophysis of the pituitary gland.
Samples were removed from the remnants of the cerebrum, diencephalon, and organs (thymus, lung, myocardium, jejunum, ileum, mesenteric lymph node, liver, spleen, kidney, and striated muscle), and 3 independent real-time PCR protocols were conducted to detect genomes of bovine viral diarrhea/ mucosal disease virus, bluetongue virus serotype 8, and the novel SBV Initial retrotranscription of the RNA genomes was followed by quantitative (real-time) PCR.
injected L-Arg increased both L-Arg and L-Orn concentrations in the telencephalon and diencephalon of chicks 10 min post-injection (Suenaga et al.
It is considered part of the diencephalon and sits near the base of the third ventricle, in approximately the anatomic center of the brain.
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Structure Neocortex Hippocampus Piriform cortex Subpallial structures Hypothalamus Diencephalon Midbrain Cerebellum Hindbrain Spinal cord Vascular supply Imaging techniques
Cervids typically have the most abundant and predictable PrPres in the dorsal motor vagus nucleus (obex), olfactory cortex, and diencephalon (including thalamus, hypothalamus, metathalamus, and epithalamus) (2,33).
It covers the motor system (central and peripheral components and lesions affecting them, brainstem (surface anatomy and topography, cranial nerves, and disorders), cerebellum structures, connections and disorders), the diencephalon and autonomic nervous system, the limbic system, basal ganglia, cerebrum (including cerebral white matter), coverings of the brain and spinal cord and cerebrospinal fluid, and blood supply and vascular disorders for the entire system.
It is seen with lesions involving the upper brainstem and diencephalon.