Purpose: Proton magnetic resonance spectroscopy (MRS) was used to iden
tify specific in situ metabolic markers for seizures and seizure-induc
ed neuronal damage. Kainic acid (KA)-induced seizures lead to histopat
hologic changes in rat brain. The protective effect of cycloheximide t
reatment against neuronal damage caused by KA-induced seizures was stu
died, using in Situ proton MRS imaging technique. Methods: Rats were p
retreated with placebo or cycloheximide 1 h before KA injection. Rat b
rains (n = 25) were scanned at the level of the hippocampus before, du
ring, and 24 h after seizures. Spectra were recorded and the relative
ratios of N-acetylaspartate (NAA), choline (cho), and lactate (Lac) to
creatine (Cr) were calculated and compared between groups. Results: A
significant increase in Lac ratios was observed in KA-treated rats du
ring and 24 h after seizure onset and this increase was prevented by c
ycloheximide pretreatment. NAA ratios were significantly higher during
the ictal phase following KA treatment and this effect was not affect
ed by cycloheximide pretreatment. Nissl staining confirmed previously
reported prevention of KA-induced neuronal loss in CA3 and CA1 areas o
f the hippocampus by cycloheximide pretreatment. Conclusions: Our resu
lts suggest that in situ Lac increase is a marker of seizure-induced n
euronal damage, whereas N-acetylaspartate (NAA) changes during and aft
er status epilepticus may be a reflection of neuronal activity and dam
age, respectively.