Mossy fiber sprouting is dissociated from kindling of generalized seizures in the guinea-pig

Controversy surrounds whether aberrant mossy fiber sprouting in the hippocampus is necessary for the establishment of seizure states. We investigated the association between mossy fiber sprouting and kindling in guinea-pigs, using either single-site or alternate-site stimulation. Kindling with single-site amygdaloid stimulation did not induce significant sprouting, despite the development of partial seizures. In contrast, single-site septal and alternating amygdaloid-septal stimulation produced moderate but significant sprouting in about 60% of animals that failed to develop stage 5 generalized seizures. Since the magnitude of sprouting was similar despite striking differences in the intensity of seizures that developed, we conclude that mossy sprouting is not causally associated with seizure development.