Content of DNA and dry weight of the nuclei of neurons of the external geniculate body and retina of the eye in guinea pigs.

The amount of DNA and the dry weight of the nuclei of cells of the external geniculate body, as well as the photoreceptor, bipolar, and ganglionic cells of the retina of the eye, were studied at the early stages of postnatal development of guinea pigs by the methods of cytospectrophotometry and interferometry on prints of the tissue. In the photoreceptor and bipolar cells of the retina, a stable, diploid amount of DNA is detected. In the ganglionic cells and nerve cells of the external geniculate body, in addition to the diploid cells a small group of tetraploid cells was detected. The dry weight of the nuclei of the external geniculate body and retina increased appreciably on the third day of postnatal development.