Tritium quench in autoradiography during postnatal development of rat forebrain

Quantitative autoradiography of tritium-labeled brain tissue requires correction for regional and age-dependent changes in tritium quenching. Correction values are determined using chloroform extraction of brain sections labeled with tritiated 2-deoxyglucose ([3H]2DG) in adult rats and rats at postnatal ages of 5, 14 and 21 days. Conditions are described for intraperitoneal injection of [3H]2DG for labeling neonatal animals which maximize the formation of [3H]2-deoxyglucose-6-phosphate. Tritium quench correction coefficients are determined in 65 brain regions at each age. Autoradiographic tritium quench increases during postnatal development in all brain regions, with the rate and extent of change corresponding to the development of myelination in different structures. Quench coefficients range from 6 to 45% in 5 day animals and from 21 to 108% in adult animals. Gray matter structures have a major increase in tritium quenching between postnatal days 5 and 14. Quench coefficients in white matter-containing structures increase throughout postnatal development at region-specific rates. These data may be used to correct regional differences in tritium quenching for autoradiographic studies of postnatal development.