Lenticular nucleus

Figure 6.6. Distribution of 5-HT4 receptors. The 5-HT4 receptor subtype is coupled to a G protein that stimulates the intracellular messenger adenylate cyclase that, in turn, regulates neurotransmission. In the human brain, a high density of 5-HT4 receptors has been identified in the striatonigral system, notably in the caudate nucleus, lenticular nucleus (putamen and globus pallidus) and the substantia nigra. Lower levels of expression of the 5-HT4 receptor have been shown in the hippocampus and...

The disease is a rare inherited disorder characterized by a progressive degeneration of the lenticular nucleus in the brain and by cirrhosis of the liver. Barbeau et al. (Bl) studied a case of Wilson s disease which presented normal ceruloplasmin and serum copper values but increased excretion of kynurenine, 3-hydroxykynurenine, and conjugated anthra-nilic acid in xurine after an oral dose of 2 g L-tryptophan. This defect in tryptophan metabolism could be related to that of other amino acids and to the actual content of ceruloplasmin in Wilson s disease (Bl). These findings corroborated Marver s (M2) investigations demonstrating a definite excretion of kynurenine and 3-hydroxykynurenine in abnormal proportions after a tryptophan load in a case of Wilson s disease. 

CNS Copper deposits affect the whole CNS. Degeneration and tissue loss as well as atrophy of the lenticular nucleus prevail. Occasionally, there are also small necrotic foci with a diffuse spot-like distribution. Micro-cavernous lesions occur due to the destruction of nerve cells. Myelinized fibres and oligodendrocytes are present, but there is also cellular hyperplasia and hypertrophy of astrocytes rich in protoplasm. The cerebral changes detectable in CT scanning do not correlate with the degree of severity of the functional disturbances (320, 335) however, there is a close correlation between the lesions detected by MRI and certain neurological findings. (350, 366, 376, 388) (s. p. 615)... 

An MRI brain scan may demonstrate typical changes such as atrophy and densification in the basal ganglia and the lenticular nucleus (i. e. in the putamen and the globus pallidus). The cause of the particular sensitivity of these regions is unknown. 

Spiller, W. G., The family form of pseudo-sclerosis and other conditions attributed to the lenticular nucleus. J. Nervous Mental Disease 43, 23-36 (1916). 

During the early stages of WD the liver is capable of storing 30 to 50 times more copper than normal, with no overt clinical disorder. When large amounts of copper are ultimately released from the liver into the bloodstream - as in the case of massive necrosis of liver parenchyma - a severe hemolytic anemia may ensue (Erslev 1986). The release of copper into the bloodstream is usually more gradual and, over the years, plasma concentrations of free copper may rise from little more than zero to 25 to 50 pg 100 mD or more. The increased levels of blood copper cannot be excreted due to biliary excretion failure, and so the copper will slowly accumulate in the various compartments of the body, especially the lenticular nucleus of the brain. If untreated, WD is ultimately fatal. 

Fig. 3.8 Axial NCCT images showing the MCA territory regions as defined by ASPECTS, (a) C Caudate /insular ribbon ICinternal capsule L lenticular nucleus Ml anterior inferior frontal MCA cortex M2 temporal lobe MCA cortex lateral to the insular ribbon M3 posterior temporal MCA cortex, (b) M4, M5, and M6 corresponding anterior, lateral, and posterior MCA cortices immediately rostral to Ml, M2, and M3, respectively...

Figure 7. Warm dust emission in early-type galaxies. Six galaxies are shown, each with separate images in stellar emission (3.6 /um) and warm dust emission (8.0 pm non-stellar ). The top three galaxies are classified as ellipticals and show no sign of warm dust emission at 8.0 pm. The bottom three galaxies are classified as lenticulars and show resolved warm dust. NGC 4203 appears face-on with several spiral arms emanating out from its nucleus, NGC 5363 appears somewhat inclined and shows two arms, and NGC 1023 shows a smooth distribution of dust.

The generation of free oxygen radicals is implicated to have a role in the formation of cataracts. Mice exposed to hyperbaric oxygen develop cataract. Lens epithelial cells in vitro exposed to oxygen at increased pressures show a decreased mitotic activity. " Both decreased and unaltered levels of reduced glutathione, an oxygen radical scavenger, have been reported and this loss has been localized to the nucleus rather than the lens conex. Correlative clinical and laboratory studies are warranted to establish the causal role of HBO in lenticular myopic shift of the eye. 

---