Circadian oscillations of nucleic acid and protein content in functionally different neuron-neuroglia units of rat central nervous system.

Scanning integrating visible cytospectrophotometry of gallocyanin-, amido black-, fast green- or ammoniacal silver-stained sections of various areas of the central nervous system of adult rats sacrificed at 4 h intervals has demonstrated the presence of circadian changes in RNA, total protein and total histone content as well as in arginine-rich to lysine-rich histone ratio in the neurons and in their perineuronal satellite neuroglia. The peak of the content per cell of the macromolecular components studied was in some cases elevated above their lowest level up to 1.7-fold. The zenith in the content of neuronal RNA coincided as a rule with the nadir in the content of glial RNA whereas no such opposition was observed with respect to the protein or histone content as well as to the arginine- to lysine-rich ratio in the neurons and in their glial satellite cells. The data obtained have confirmed earlier observations that under changed conditions of neuron functioning, the changes in the nervous system metabolism occur which are localized not only in the neurons but also in the neuroglia, the metabolic response in the glial cells being characterized, depending on peculiarities of the particular neuron activity, both by similarity and by some differences as compared with the neuronal metabolic response. A synchronizing effect of environmental and/or internal factors on the macromolecular metabolism within various cell populations of the central nervous system is discussed.