Administration of caspase 3 inhibitor during and after status epilepticus in rat: effect on neuronal damage and epileptogenesis

S Narkilahti, J Nissinen, A Pitkänen - Neuropharmacology, 2003 - Elsevier
S Narkilahti, J Nissinen, A Pitkänen
Neuropharmacology, 2003Elsevier
Symptomatic temporal lobe epilepsy typically develops in three phases: brain damage→
epileptogenesis→ spontaneous seizures (epilepsy). The challenge is to prevent
epileptogenesis after injury. We hypothesized that alleviation of damage by caspase
inhibitors will reduce epileptogenesis or at least have disease-modifying effects (less severe
epilepsy, milder cognitive decline). Epileptogenesis was triggered by amygdala stimulation-
induced status epilepticus (SE) in rats and spontaneous seizures were monitored with video …
Symptomatic temporal lobe epilepsy typically develops in three phases: brain damage → epileptogenesis → spontaneous seizures (epilepsy). The challenge is to prevent epileptogenesis after injury. We hypothesized that alleviation of damage by caspase inhibitors will reduce epileptogenesis or at least have disease-modifying effects (less severe epilepsy, milder cognitive decline). Epileptogenesis was triggered by amygdala stimulation-induced status epilepticus (SE) in rats and spontaneous seizures were monitored with video-electroencephalography (EEG). First, we tested the neuroprotective effect of a 1-week treatment with caspase 1, 3 or 9 inhibitors (3 μg/d/i.c.v., started 3 h after the beginning of SE). The least damage to the hippocampus was observed in animals treated with the caspase 3 inhibitor (z-DEVD-fmk) which reduced the enzyme activity to 6% of that in the vehicle group. Thus, z-DEVD-fmk was chosen for long-term studies, in which the treatment regime remained the same except the dose was doubled (6 μg/d/i.c.v.). Video-EEG monitoring was performed for 3 to 4 weeks, starting either 8 or 14 weeks after SE. One group of animals was tested in water-maze and fear-conditioning tests, and all animals were perfused for histological analysis. Treatment with the caspase 3 inhibitor neither prevented the development of epilepsy, nor had any disease-modifying effects. Mossy fibre sprouting, however, was reduced. The present data indicate that administration of z-DEVD-fmk monotherapy was not antiepileptogenic despite its short-term neuroprotective effects. These findings challenge the idea that prevention of cell death is the primary target for the development of antiepileptogenic compounds.
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