ACUTE EFFECTS OF METHOXYPYRIDOXINE ON HIPPOCAMPAL ENDhyphen;BLADE NEURONS; AN EXPERIMENTAL STUDY OF ldquo;SPECIAL PATHOCLISISrdquo; IN THE CEREBRAL CORTEX

摘要

Architectonic fields in the hippocampus are defined largely in terms of the general histological characteristics of their pyramidal neurons (1ndash;4), but these features do not account for the relative vulnerability of elements in different segments of the pyramidal band to various pathological conditions directly or indirectly affecting the central nervous system (5). To explain regional differences in hippocampal cellular pathology, two hypotheses have been suggested. One attributes neuronal damage in various sectors to local vascular and/or hemodynamic alterations (6) and is presumably supported by a variety of data (7ndash;8). The other considers selective vulnerability or ldquo;special pathoclisisrdquo; a reflection of physico-chemical differences in neurons in different architectonic fields (4) and ldquo;remains in the nature of a statement of the problemrdquo; (5).In the present studies an antimetabolite of pyridoxine, methoxypyridoxine, has been employed as an analytical tool to attain a twofold objective: (a) to induce acute histopathological changes in neurons in different segments of the hippocampal pyramidal layer, and (b) to determine whether or not these selective changes may be interpreted primarily in terms of regional differences in the biochemical properties of the affected neurons. Analyses of the complex histopathological effects of methoxypyridoxine on elements in other parts of the central nervous system will be presented in a subsequent report. Some of the alterations in brain amino acid metabolism accompanying seizures induced by methoxypyridoxine have been considered elsewhere (9).