[The effect of early visual deprivation on the level of N-acetyl-1-asparaginic acid and the activity of phosphate-activated glutaminase in visual analyzer structures and various regions of the dog cerebral cortex and cerebellum].

Under conditions of 45-days visual deprivation content of N-acetyl-L-aspartic acid was considerably increased in visual cortex (field 17) tissues and decreased in the superior colliculus and exterior geniculate body. At the same time, content of N-acetyl-L-aspartic acid was not altered in the visual cortex mitochondrial fraction; in the outer structures studied level of this amino acid was distinctly decreased both in tissues and mitochondrial fractions. After prolongation of the visual deprivation up to 90 days content of N-acetyl-L-aspartic acid was sharply decreased in tissues and mitochondrial fractions of all the formations studied of dog brain visual analyzer. The maximal 4.5-fold decrease was found in mitochondrial fractions of the visual analyzer (field 17), in the exterior geniculate body and superior colliculus content of the amino acid was decreased 2.4-3.9-fold as compared with controls. In 90 days-long visual deprivation total activity of phosphate-dependent glutaminase was considerably increased (1.18-3.71-fold as compared with controls) in myelinic (A), membraneous (B), light (C), and heavy synaptosomal and synaptic mitochondrial (E) subfractions of the visual cortex (field 17). The rate of the enzyme activation was distinctly higher in these subfractions as compared with that of the motor and parietal cortical subfractions. After 90 days-long visual deprivation the similar alterations were found in A, B, D and E cerebellum subfractions but these alterations were less distinct as compared with the visual, motor and parietal subfractions.