Growth-associated protein GAP-43, a phosphoprotein enriched at presynaptic
nerve terminals, is thought to be involved in axonal outgrowth and plastici
ty in synaptic connections. To explore the synaptic remodeling under the ep
ileptic conditions, we examined GAP-43 expression in brain specimens surgic
ally resected as epileptogenic foci from 17 patients with cortical dysplasi
a. In situ hybridization with GAP-43 antisense riboprobe showed significant
ly increased signals in the dysplastic large neurons of cortical dysplasia.
Specific distribution with increased immunoreactivity for GAP-43 was not s
hown in the dysplastic cortex. These results suggest that GAP-43 gene expre
ssion is over-expressed in the dysplastic large neurons, reflecting activat
ed synaptic remodeling in the epileptic condition of cortical dysplasia, al
though the precise site of accelerated synaptic rearrangement remains unkno
wn. NeuroReport 11:1815-1819 (C) 2000 Lippincott Williams & Wilkins.