Cerebellar Ganglioside Research Articles

Cerebellar lipid differences between R6/1 transgenic mice and humans with Huntington’s disease

Huntington's disease (HD) is a progressive neurodegenerative disorder characterized by motor, psychiatric, and cognitive abnormalities. In this present study, we tested whether abnormal motor behavior in a mouse model of HD, the R6/1 transgenic (Tg) mice, was associated with changes in cerebellar lipid composition and gene expression. We report altered motor behavior, which was associated with abnormal expression of glycosyltransferase genes in the cerebellum of R6/1 Tg mice. Cerebellar wet weight and total ganglioside concentration was significantly lower in R6/1 Tg mice than in wild-type (Wt) mice. Furthermore, the Purkinje cell-enriched ganglioside LD1 and the granule cell-enriched ganglioside GD1a were significantly lower in R6/1 Tg mice than in Wt mice. The myelin-enriched lipid sulfatides was also reduced in the cerebellum of R6/1 Tg mice. In contrast to the R6/1 Tg mice, total cerebellar ganglioside concentration did not differ between HD and control subjects. However, expression of several cerebellar glycosyltransferases genes was significantly less in HD subjects than in control subjects. Our findings indicate that the R6/1 Tg mice have severe cerebellar glycosphingolipid (GSL) abnormalities that may account, in part, for their abnormal motor behavior. Although the cerebellar lipid abnormalities found in the R6/1 Tg mice were not found in these HD subjects, the R6/1 Tg mice may be useful for evaluating the role of GSLs in cerebellar development.

Altered cerebellar ganglioside pattern in rett syndrome

Abstract The membrane lipids were examined in the cerebellum from five patients who died with Rett syndrome (RS). The major lipids of cerebellar folia and white matter did not show any difference compared with age-matched controls. There were slightly low values for cerebrosides, a biochemical marker for myelin, in cerebellar folia but high values in white matter of corpus medullare. The ganglioside concentration was reduced in one case which had shown marked astrocytosis at histological examination. Astrocyte associated gangliosides were significantly increased in this case, but their proportion was also increased in the four other patients. Lacto series acidic glycosphingolipids, 3′-LM1 and LK1, closely associated with Purkinje cells were reduced in the Rett cases which fits well with neuropathological examination demonstrating the loss of Purkinje cells. The most prominent finding was a decreased proportion of gangliosides GD1a and GT1b in cerebellar folia and white matter. The decreased proportion of GD1a might reflect an abnormality of synaptogenesis in RS and would be compatible with the clinical profile of this disease.

Cerebellar ganglioside abnormalities in pcd mutant mice

The distribution of cerebellar gangliosides was studied in Purkinje cell degeneration (pcd/pcd) mutant mice at postnatal days 25, 30, 50, and 150. These mutants lose the majority of Purkinje cells between 18 and 50 days of age. A reactive gliosis accompanies Purkinje cell loss and a partial loss of granule cells occurs in pcd/pcd mice older than p50. Purkinje cell loss is associated with significant reductions in cerebellar weight and ganglioside concentration. This neuronal loss was also developmentally correlated with reductions of gangliosides (GT1a/LD1 and GT1b and with elevations of GD3. These results agree with previous findings in other cerebellar mutants that GT1a/LD1 and GT1b are concentrated in Purkinje cells and that GD3 is enriched in reactive glial cells. A slight, but significant, reduction in GD1a concentration occurred only in older pcd/pcd mice, consistent with previous findings in weaver and staggerer mice that GD1a is enriched in mature granule cells. The findings with pcd/pcd and other neurological mutants indicate that certain gangliosides can serve as cell-surface markers for monitoring changes in cerebellar cytoarchitecture that accompany development or disease.

Effect of Purkinje cell loss on cerebellar gangliosides in nervous mutant mice.

The distribution of cerebellar gangliosides was studied in adult (73 +/- 2 days) nervous (nr/nr) mutant mice which lose 50-90% of their Purkinje cells. This neuronal loss is associated with significant reductions in cerebellar weight and ganglioside concentration. The cerebellar dry weights (mg) and the ganglioside concentrations (microgram N-acetylneuraminic acid per 100 mg dry weight) in nr/nr mice and age-matched normal littermates (+/?) are 7.4 +/- 0.3 mg and 13.2 +/- 0.4 mg; and 411.7 +/- 4.8 micrograms and 438.5 +/- 2.1 micrograms, respectively. Abnormalities were also observed for the concentration of certain ganglioside species. Most notably, GT1a is significantly reduced by 42%, and GD3 is significantly increased by 29% in the nr/nr mice compared to the +/? mice. The nr/nr mice also express a slight but significant reduction in GT1b. No ganglioside abnormalities were observed between the nr/nr and +/? mice in cerebral cortex. We previously found reduced cerebellar GT1a content in other mutants that also lose Purkinje cells, i.e., sg/sg, pcd/pcd, and Lc/+. GT1a is not reduced, however, in wv/wv mice that lose mostly granule cells. The findings in nr/nr mice are therefore consistent with our hypothesis that GT1a is enriched in Purkinje cells. GD1a, which is enriched in mature granule cells, is not reduced in the nr/nr mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Oral and Intraperitoneal Administration of N-Acetylneuraminic Acid: Effect on Rat Cerebral and Cerebellar N-Acetylneuraminic Acid

Rat pups were administered N-acetylneuraminic acid (NANA) by i.p. injection or via a feeding catheter for eight consecutive days beginning on d 14 of life. All pups were given the identical dose: 1.0 mg on d 1 and 2 and 1.2 mg on the remaining days, or approximately 20 mg/kg body weight per day. A control group was injected i.p. with glucose instead of NANA. On the morning of d 25, pups were decapitated, and the heads were frozen immediately in liquid nitrogen. The brains were later dissected and analyzed for both cerebral and cerebellar ganglioside and glycoprotein NANA. Administration of NANA by both oral and i.p. routes resulted in significantly more cerebral and cerebellar ganglioside and glycoprotein NANA than did glucose injection (with the exception of cerebellar glycoprotein NANA after NANA intubation). There were no significant differences in NANA concentration in these brain fractions for the two routes of NANA administration.

Cellular distribution of gangliosides in the developing mouse cerebellum: analysis using the staggerer mutant.

The distribution of cerebellar gangliosides was studied in staggerer (sg/sg) mutant mice, where the majority of granule cells die after completing their migration across the molecular layer. In addition, the external granule cell layer in sg/sg mice persists longer than in normal mice. Moreover, in the sg/sg cerebellum, Purkinje cells are significantly reduced in number, and almost none have tertiary branchlet spines. The loss of Purkinje cells and granule cells in sg/sg mice is accompanied by an early-onset reactive gliosis that continues through adulthood. By correlating changes in ganglioside composition with the well-documented histological events of cerebellar development in normal and sg/sg mice, we obtained strong evidence for a nonrandom cellular distribution of gangliosides. The sharpest reduction in the GD1a content of sg/sg cerebellum occurred after 15 days of age, coincident with granule cell loss. GT1a, on the other hand, was significantly reduced from 15 through 150 days in the sg/sg mice. GD3 is a major ganglioside of the undifferentiated granule cell, but it becomes rapidly displaced by the more complex gangliosides with the onset of granule cell maturation. In the sg/sg mice, GD3 persisted at abnormally high levels from 15 to 28 days and then accumulated through adulthood. These findings, and those from other cerebellar mouse mutants, suggest that GD1a is enriched in granule cells and that GT1a is enriched in Purkinje cells. Our findings also suggest that GT1a is more concentrated in branchlet spines than in other regions of the Purkinje cell membrane. GT1b appears to be enriched in both granule cells and Purkinje cells, whereas GM1 appears to be enriched in myelin. Furthermore, the apparent persistence of the embryonic ganglioside GD3 in sg/sg mice results from an early-onset reactive gliosis, together with a partial retardation in granule cell maturation. The accumulation of GD3 beyond 28 days reflects the continued accretion of GD3 in reactive glia.

Cerebellar gangliosides and phospholipids in mutant mice with ataxia and epilepsy: the Tottering/Leaner syndrome

Cerebellar gangliosides and phospholipids in mutant mice with ataxia and epilepsy: the Tottering/Leaner syndrome

Effects of Administration of N-Acetylneuraminic Acid (NANA) on Brain NANA Content and Behavior

Rat pups were malnourished during the first 3 weeks after birth. Experimental rats were injected intraperitoneally with 1 mg N-acetylneuraminic acid (NANA) per 50 g body weight daily from 14 to 21 days postnatally. Control animals were similarly injected with 1 mg glucose per 50 g body weight. At 21 days of age, the rats were tested in an open field and their brains analyzed for protein, DNA, ganglioside NANA and glycoprotein NANA. The administration of NANA was associated with an increase in cerebral and cerebellar ganglioside and glycoprotein NANA concentrations. However, it had no effects on brain weight, cell size and number. There was also a reduction in the expected behavioral abnormalities secondary to malnutrition. At 21 days of age, similarly treated littermates of the experimental animals were weaned to a stock diet and tested in a Y maze at 6 months of age. Rats treated with NANA learned the maze quicker than controls and the previously noted changes in brain biochemistry were found to have persisted. Intraperitoneal injection of [14C]NANA into malnourished rats during the same period showed that it was readily incorporated into brain glycoproteins and gangliosides. The possibility that the brain concentration of NANA has an effect on behavior is discussed.

Effects of Environmental Stimulation on Brain N-Acetylneuraminic Acid Content and Behavior

A study was conducted in which the nutritional and early stimulation conditions of rat pups were manipulated during the first 3 weeks of life. Early stimulation reduced the change in open-field behavior caused by malnutrition at 21 days postnatally. The cerebrum and cerebellum were analyzed for ganglioside and glycoprotein N-acetylneuraminic acid (NANA), DNA and protein content. The improved behavioral performance was associated with a significantly higher ganglioside and glycoprotein NANA content in both brain areas analyzed. The remaining rats from each litter were weaned onto a standard laboratory stock diet at 21 days of age and housed individually until age 6 months. At this time, their performance in a Y maze was tested. Once again early stimulation was associated with an improved ability to learn the maze. The biochemical changes persisted into adulthood in the stimulated groups with the exception that the difference in cerebellar ganglioside content had disappeared by this time. The results are discussed with respect to the possible role of NANA in behavior.

High-performance thin-layer chromatography and densitometric determination of brain ganglioside compositions of several species

Improved resolution of complex brain ganglioside mixtures was achieved by high-performance thin-layer chromatography. The percentage distribution of individual gangliosides was then determined by direct densitometric seanning, employing a transmittance mode, of the resorcinol-positive spots on the plate. As little as 90 pmol (29 ng) of lipid-bound sialic acid could be detected with a good signal-to-noise ratio. A linear detector response was observed up to 3.0 μg of lipid-bound sialic acid. The brain white matter ganglioside patterns of eight animal species, including human, chimpanzee, monkey, chicken, bovine, sheep, and pig, were examined in detail. In addition, human brain gray matter, rat cerebral, rat brain gray matter, and rat cerebellar ganglioside patterns were also studied. Ganglioside G M4 (G 7) was found to be one of the major components in primate and chicken brain white matter, but it represented only a minor ganglioside in other species. Other major gangliosides in all brain samples studied were G M1, G D1a, G D1b, and G T1b. G M1 was more abundant in white matter than in gray matter. G T1a, a recently discovered ganglioside species, was found in all species examined, but was most abundant in the rat cerebellum. The latter source also contained high proportions of G T1b and G Q1b.

Lipid composition in postnatal methylazoxymethanol-treated swiss albino mouse cerebellum.

Postnatal Swiss albino mice were treated with with methylazoxymethanol acetate (MAM) or saline and sacrificed at 25 days of age. Granule cell depletion resulted. Significant reduction in the cerebellar weight, protein, ganglioside sialic acid , cerebrosides, sulfatides, and phospholipids were documented. There was not, however, selective reduction of any component known to be associated with the synaptic structures. Specific association of cerebellar ganglioside with its granule cell population was not substantiated. Cerebroside/sulfatide ratios were not different in the two groups, indicating that significant alterations previously observed in spinal cord were not present in the cerebellum. It was concluded that the bulk of cerebellar granule cells and their synaptic connections could be deleted without affecting total ganglioside and phospholipid concentrations.