Neurochemical and morphological studies on the myelin of peripheral nervous system from Shiverer mutant mice: absence of basic proteins common to central nervous system

Shiverer mouse is characterized by poor lamella formation and absence of major dense line in the CNS myelin. PNS of the Shiverer was normal with regard to myelin lamellar formation, immunohistochemical staining of the Schwann cells by S-100 protein, and the activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase. Analysis of the purified myelin by SDS-polyacrylamide gel electrophoresis revealed that P1 and Pr, which are common to BP in CNS, and PM protein were missing, while P0 and P2 proteins were of the same level as the control.

Cerebellar hypoplasia in the Gunn rat with hereditary hyperbilirubinemia: immunohistochemical and neurochemical studies

Immunohistochemical reactions were conducted, using the antibodies against GFA and S-100 proteins on sections of cerebellum from the homozygous (jj) and the heterozygous (Jj) Gunn rats. Hypertrophy of the fibrous astrocytes was observed but hyperplasia of the glial cells was not. Although the molecular layer was very thin, the Bergmann fibre appeared normal. Among the free amino acids in the cerebellum from the jj rat, glutamate concentration decreased to two-thirds of the control level. The protein profile of the cerebellum from the jj rat obtained by SDS-polyacrylamide gel electrophoresis revealed that the amount of P400 protein that is characteristic of Purkinje cells decreased considerably and there were also some changes of the other unidentified proteins. By two-dimensional electrophoresis, it was observed that in the supernatant from the jj rat cerebellum one protein spot diminished and in the particulate fraction from the jj rat one spot was enormously increased. The activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase) in the cerebellum from the jj rat did not differ significantly from that of the control; however, activities of choline acetyltransferase and acetylcholinesterase of the jj rat were about twice as high as those of the control. 2-Deoxyglucose incorporation was maximum in the granular layer from both the jj and the Jj rat cerebella. However, the incorporation in the jj cerebellum was not higher than in the Jj control and even lower in some parts of the jj cerebellum than in the control Jj cerebellum.

Effect of food restriction on serotonin metabolism in rat brain

The brain concentration of 5-hydroxytryptamine (5-ht) and 5-hydroxyindoleacetic acid (5-HIAA) increased in rats maintained on restricted volume of low-protein or normal-protein diet, whereas these two agents decreased in rats fed low-protein diet ad libitum. In these two food-restricted groups brain 5-HT and 5-HIAA concentrations were not correlated with brain tryptophan hydroxylase activity, but the concentrations correlated closely with cerebral tryptophan concentrations. The cerebral tryptophan concentration in the two food-restricted groups was not consistent with the total or free tryptophan concentration in plasma. In these restricted rats cerebral tryptophan concentration was elevated, and, unlike the plasma tryptophan, it showed no diurnal variation. These results suggested that tryptophan uptake into the brain from plasma was enhanced by limiting food volume intake. Tryptophan uptake was increased by glucagon injection without changing the plasma tryptophan level, but injection of hydrocortisone or insulin had little or no effect on tryptophan concentration in either the plasma or brain. D-Glucose injection elevated plasma tryptophan concentration but decreased brain tryptophan concentration.