Histochemical study of RNA content of neurones in the dorsal lateral geniculate nucleus during postnatal development.

Nuclear and cytoplasmic dLGN neurons were investigated by cytophotometric measurements of RNA. This study has been carried out in rats from birth to adulthood. In order to quantify the RNA content a cytophotometer was used. Extinction mean values were obtained which indicated RNA concentrations per surface unit. The nuclear and cytoplasmic surface were calculated simultaneously and from the product of the mean extinction and the surface the RNA total content was calculated. Our results have suggested that the changes are age-related. From day 1 to day 21 the neuronal size and RNA content increase; this may somehow be involved with the differentiation process. Around post-natal day 21 neuronal maturation may begin, reaching its optimal phase around day 42, on which the RNA concentration per surface unit, surface neuronal content and RNA total content are stable.