Cytidine-5-diphosphocholine (CDP-choline, citicoline) is an endogenous nucleoside involved in generation of phospholipids, membrane formation and its repair. It demonstrates beneficial effects in certain central nervous system injury models, including cerebral ischaemia, neurodegenerative disorders and spinal cord injury. Defective neuronal and/or glial glutamate transport is claimed to contribute to progressive loss of motor neurons (MNs) in amyotrophic lateral sclerosis (ALS). Our previous ultrastructural studies, performed on an organotypic tissue culture model of chronic glutamate excitotoxicity, documented a subset of various modes of MN death including necrotic, apoptotic and autophagocytic cell injury. The aim of this ultrastructural study was to determine the potential neuroprotective effect of CDP-choline on neuronal changes in a glutamate excitotoxic ALS model in vitro. Organotypic cultures of the rat lumbar spinal cord subjected to 100 microM DL-threo-beta-hydroxyaspartate (THA) were pretreated with 100 microM of CDP-choline. The exposure of spinal cord cultures to CDP-choline and THA distinctly reduced the development of typical apoptotic changes, whereas both necrotic and autophagocytic THA-induced MN injury occurred. These results indicate that CDP-choline treatment might exert a neuroprotective effect against neuronal apoptotic changes in a model of chronic excitotoxicity in vitro.