Gy. Bing et al., LONG-TERM EXPRESSION OF FOS-RELATED ANTIGEN AND TRANSIENT EXPRESSION OF DELTA-FOSB ASSOCIATED WITH SEIZURES IN THE RAT HIPPOCAMPUS AND STRIATUM, Journal of neurochemistry, 68(1), 1997, pp. 272-279
Systemic administration of kainic acid (KA), an analogue of glutamic a
cid, causes limbic seizures and pathophysiological changes in adult ra
ts that are very similar to human temporal lobe epilepsy. One of the e
arliest changes in gene expression after treatment with KA is the indu
ction of immediate-early genes. The fos and jun families are frequentl
y studied immediate-early genes that are induced by KA. Several groups
, including ours, have recently reported that a 35-kDa Fos-related ant
igen (FRA) is induced for a protracted time by various stimuli. It has
been suggested that this FRA is Delta FosB, which has a molecular mas
s of similar to 35 kDa, The present study characterizes the long-term
expression of FRA and Delta FosB after systemic treatment with KA. Imm
unocytochemistry and western blot analysis using an antibody that cros
s-reacts with all known FRAs showed that a 35-kDa FRA was induced at h
igh levels in both the hippocampus and striatum for up to 1 month by K
A, A semiquantitative PCR analysis showed that Delta FosB was induced
by KA, but its expression lasted for only 6 h. This result was also ve
rified by northern blot analysis, These results suggested that the 35-
kDa FRA with long-term elevated levels seen with western blot analysis
and immunocytochemistry is a new species of the FRA and not Delta Fos
B. The long-term expression of FRA in both the hippocampus and striatu
m may be associated with the pathophysiological changes after KA admin
istration.