Release of acetylcholinesterase by cultured spinal cord cells

The release of acetylcholinesterase from neurons was studied using cultured chick-embryo spinal-cord cells. Cells dissociated from 12-day-old chick-embryo spinal cords were grown in culture for 10-12 days. Numerous well differentiated spinal neurons were found after 7-10 days in culture. Acetylcholinesterase activity per dish increased by 60-fold from days 2-12. Acetylcholinesterase was released into the surrounding media by the cells when they were incubated either in the standard culture medium or the serum-free medium. Acetylcholinesterase release was significantly reduced when protein synthesis and microtubules were disrupted by cycloheximide and colchicine, respectively. Histochemical localization of acetylcholinesterase indicated that the synthesis and relase of acetylcholinesterase are attributable to neurons. Cultured chick-embryo brain and neuroblastoma cells also released acetylcholinesterase into the media. These results are discussed with regard to possible physiological roles for acetylcholinesterase secretion from neurons.