Polioencephalitis Polioencephalitis Polioencephalitis is a viral infection of the brain, causing inflammation within the grey matter of the brain stem. The virus has an affinity for neuronal cell bodies and has been found to affect mostly the midbrain, pons, medulla and cerebellum of most infected patients. The infection can reach up through the thalamus and hypothalamus and possibly reach the cerebral hemispheres. The infection is caused by the poliomyelitis virus which is a single-stranded, positive sense RNA virus surrounded by a non-enveloped capsid. Humans are the only known natural hosts of this virus. The disease has been eliminated from the U.S.
Hypothalamus supraoptic nucleus of the hypothalamus produce neurohypophysial hormones, oxytocin and vasopressin. These hormones are released into the blood in the posterior pituitary. Much smaller parvocellular neurosecretory cells, neurons of the paraventricular nucleus, release corticotropin-releasing hormone and other hormones into the hypophyseal portal system, where these hormones diffuse to the anterior pituitary. The hypothalamic nuclei include the following: "See also:" ventrolateral preoptic nucleus, periventricular nucleus. The hypothalamus is highly interconnected with other parts of the central nervous system, in particular the brainstem and its reticular formation. As part of the limbic system, it has connections to other limbic structures including the