We examined the effects of age on kindled seizure development, benzodiazepine receptor binding, and kindled seizure-induced increases of benzodiazepine receptor binding. The results disclosed that: development of kindling required greater numbers of stimulations in middle-aged than in young-adult animals; in comparison to young-adult animals, middle-aged animals exhibited increased benzodiazepine receptor binding in the dentate gyrus of hippocampal formation: and no age-related differences existed in the effects of seizures on benzodiazepine receptor binding. We suggest that senescence-related impairment of kindling development is due at least in part to alterations in the hippocampus, and that the increased benzodiazepine receptor binding in dentate gyrus may be one of the factors responsible for this impairment.