Dendritic alterations in rat isocortex within an iron-induced chronic epileptic focus.

Ferrous chloride was injected into the rat isocortex in 5-microliters volumes as an aqueous solution with a concentration of 100 mM. Bursts of epileptiform discharges were sustained throughout the 6 weeks of observation. Nissl and Golgi-Cox stains showed gliosis and neuronal loss within the injection site. Neurons adjacent to the cavitory lesion showed deformity of dendrites, dendritic nodularity, loss of spines, and string-of-beads deformity. These changes are identical to those found in human epileptogenic foci.