Immunohistochemical changes of striatal interneurons in the gerbil were investigated 1 h-7 days after 10 min cerebral ischemia. Marked reduction of parvalbumin-immunoreactive interneurons was seen in the striatum from 24 h after ischemia. MAP2 (microtubule-associated protein 2) immunoreactivity markedly decreased in striatal neurons 5 h after ischemia but was unaffected in interneurons. Thereafter, a severe loss of MAP2 immunoreactivity in the interneurons was found 48 h and 7 days after ischemia. The results demonstrate that transient cerebral ischemia can cause a loss of parvalbumin and MAP2 immunoreactivity in interneurons in the dorsolateral striatum in a delayed fashion as compared with a rapid loss of striatal neurons.