K. Kashihara et al., TEMPORAL PATTERN OF AP-1 DNA-BINDING ACTIVITY IN THE RAT HIPPOCAMPUS FOLLOWING A KINDLED SEIZURE, Neuroscience, 80(3), 1997, pp. 753-761
DNA binding by transcripton factor AP-1 was enhanced remarkably follow
ing kindling stimulation in rat amygdala. Maximum increase occurred 2h
after stimulation with return to baseline within 24 h. Supershift and
western analyses revealed that 38,000 mol. wt Fos-related antigen and
JunD were the main components of the evoked AP-1 complexes at the tim
e their induction reached maximum. AP-1 induction 2h after the last ki
ndling stimulation was more prominent in samples from previously kindl
ed rats than in those from non-kindled rats. This study sought to esta
blish the role of AP-1 in plastic changes of the hippocampus associate
d with kindling. Male Sprague-Dawley rats were kindled from the left a
mygdala until they exhibited Racine(15) class 5 generalized seizures.
Nuclear proteins were extracted from dorsal hippocampi obtained From 0
to 24 h after final stimulations. From these, we evaluated the tempor
al pattern of DNA binding by AP-1 using a gel mobility-shift assay wit
h a P-32-labelled AP-1 probe. Supershift and western analyses were add
ed to investigate components of the seizure-evoked AP-1 complexes. Our
results suggest that the basal level of AP-1 complexes is not associa
ted with the seizure susceptibility in kindling. However, development
of kindling appears to facilitate stimulus-evoked AP-1 induction, prob
ably via plastic changes in the central nervous system. AP-1 may media
te such changes by regulating expression of certain genes. (C) 1997 IB
RO. Published by Elsevier Science Ltd.