A combined method of immunocytochemistry and [3H]thymidine autoradiography was devised to analyze the time of production of chemically characterized neurons. The method consisted of the following steps: 1) [3H]thymidine injection in pregnant animals, 2) immunocytochemistry using peroxidase and anti-peroxidase (PAP) techniques, and 3) autoradiography. The technical problems of these methods are discussed.
