Triiodothyronine-Induced Shortening of Chromatin Repeat Length in Neurons Cultured in a Chemically Denned Medium


  • This work was presented in part at the 6th General Meeting of the European Society for Neurochemistry, held September 1–6, 1986, in Prague, Czechoslovakia, and an abstract has been published.

Address correspondence and reprint requests to Dr. I. Di Liegro at Dipartimentp di Biologia Cellulare e dello Sviluppo, via Archirafi 22, 90123 Palermo, Italy.


Abstract: At the time of terminal differentiation, mammalian cortical neurons undergo a dramatic change in the structural organization of their chromatin: the nucleosomal repeat length shortens from ∼200 base pairs in fetuses to a value of 165 base pairs after birth. These events occur several days after the end of neuronal proliferation. Previously, we reported that rat cortical neurons cultured in a very selective synthetic medium were not yet programmed to these events at the end of mitotic cycles. Herein, we report that addition of triiodothyronine to neuronal cultures induces a shortening of the chromatin repeat length comparable to the natural one.