Neuronal GM1 gangliosidosis in a Siamese cat with beta-galactosidase deficiency

A juvenile Siamese cat with severe, progressive motor disability was shown to have extensive neuronal degeneration caused by accumulation of GM(1) ganglioside. Tissues from brain and kidney were markedly deficient in beta-galactosidase activity. The disease in this cat is thought to be inherited as an autosomal recessive trait, and is strikingly similar to juvenile GM(1) gangliosidosis of children.

Biochemical approaches to the nosology of nervous system defects, I

In this brief introduction an attempt is made to indicate some of the approaches to degenerative diseases of the nervous system and directions of future research. The details of the biochemical delineation of particular disease processes will be covered by others. Following will be an introduction to the biochemical approaches to genetically determined diseases which affect the developing nervous system. The sequence of characterization of most of these disease processes has followed the sequence of the prior authors. First, there has been the clinical delineation of a particular entity. Second is the careful clinical-pathologic correlation. A third step is often the introduction of genetic data as a part of the clinical description. The further steps relate to such areas as chemical pathology, determination of underlying biochemical mechanisms, and detection of heterozygotes. Finally, one would hope to be able to apply knowledge about the disease process to rational approaches to therapy and specific genetic counseling.

gamma-Aminobutyric acid: a substrate for oxidative metabolism of cerebral cortex

Oxygen uptake of slices of cat cerebral cortex, which have been preincubated without substrate, is supported by subsequent addition of γ-aminobutyric acid or succinic semialdehyde to an extent comparable to that by glucose or l-glutamic acid. Esterification of phosphate by cat cortex mitochondria is also supported by γ-aminobutyric acid or succinic semialdehyde, which yielded P/O ratios between 2 and 3, similar to ratios obtained with pyruvate or l-glutamic acid. The relevance of these findings to functional activity of the brain is discussed particularly in reference to seizure states, where metabolic abnormalities of glutamic acid and γ-aminobutyric acid occur, and to the physiological roles which have been proposed for γ-aminobutyric acid. It is suggested that cerebral energy metabolism may in part depend upon oxidative metabolism via the glutamic-γ-aminobutyric acid pathway, which could regulate a portion of the available energy and thus affect levels of functional activity.