Orthogonal arrays are redistributed in the membranes of astroglia from alumina-induced epileptic foci.

Freeze-fracture techniques were used to examine the distribution of orthogonal arrays in the membranes of astroglia from specimens of cerebral cortex of epileptic and control rats. Astroglial membranes from experimental chronic epileptic cortex displayed normal densities of arrays in pial-glial regions surrounding the alumina granuloma. Astroglial membranes from deep parenchymal regions of epileptic cortex displayed increased numbers of arrays, especially in regions of membrane not normally displaying arrays. The apparent random distribution of these membrane specializations in reactive astroglia in alumina-induced epileptic foci is discussed in reference to one postulation of orthogonal array function.