The present study describes the identification and the ultrastructural and numerical evolution of Purkinje cell axonal swellings induced by phenytoin. Thirty male C57Bl/6J mice received phenytoin orally in doses up to 100 mg/kg daily and were killed after 3, 6, 10, 14, and 48 days of treatment. Light and electron microscopic investigations as well as morphometric analysis of cut surface area and numerical density of axonal swellings were performed. The swellings appeared as early as 6 days after initiation of treatment and gradually increased in size and frequency. Use of an anti-lymphocyte monoclonal antibody (CD 3), specifically cross-reacting with Purkinje cells, identified the swellings as dystrophic Purkinje cell axons. On grounds of their ultrastructural appearance they were classified into three distinct types occurring at different time intervals after phenytoin exposure. At 6 days, most axonal swellings contained loosely aggregated membranous vesicles and tubules in a finely granulated matrix (type 1). At 14 days, larger axonal swellings appeared characterized by the presence of three-dimensional networks of branched and anastomosing membranous tubules (type 2). At 48 days, even larger axons contained bodies of highly condensed membranous material of sometimes paracrystalline appearance (type 3). It is suggested that phenytoin-induced axonal pathology of Purkinje cells is a dynamic process characterized by the progressive accumulation of proliferating membranous material arranged in an increasingly complex fashion.
To gain further insight into the supramolecular structure and behavior of chromatin, a set of parameters has been developed for the description of cell nuclear images. These images are obtained from Feulgen-stained nuclei in semithin sections. Data are extracted by a scanning microphotometer, printed on paper tape and processed by an electronic computer. The essential principles for the selection of descriptors were that: (a) they should correspond to characteristics that are employed in classical morphology and (b) they should be subject to interpretation in categories of biochemistry or molecular biology insofar as possible. Some of these parameters deal with the size and shape of the nucleus and its
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.