SERIAL
OBSERVATION ON THE PATTERNS OF SELECTIVE NEURON INJURY AFTER PROLONGED
SEIZURES IN PREMATURE AND MATURE BRAIN
JIANG L, CAI FC, ZHANG XP
Children’s hospital, Chongqing University of Medical Sciences,
Chongqing, China
Objective: To explore the difference of the patterns on
selective neuron injury after prolonged seizures or convulsive status
epilepticus (SE) in premature and mature brain.
Methods: Adult rats (ARs) experienced 15-20min’s seizures, and
baby rats (BRs) experienced 21-75min’s seizures were sacrificed at 6 time
points during the period of 4-168 hours after seizure stopped. The necrotic
and apoptotic neurons was counted microscopically. The incidence of
apoptosis was also comparatively studied by FACS, TUNEAL and electron
microscopy.
Results: (1) The process of
neurons’ death was shown even at 4 h after sever seizures. The peak of
necrosis process reached at 24-48 h after seizure in ARs (180±38
cells), it was 2 times higher than BRs (90±5.9
cells); (2) In ARs, apoptotic neurons had been shown from the early stage
after Seizure, and the peak level of apoptosis (28±3.3%)was
reached at 24-72 h after prolonged seizure, which was 5-8 or 5-6 times
higher than control, and 4-7 or 3-4 times higher than BRs measured by FACS
or TUNEAL. (3) However there was only a mild increase of apoptotic neuron
in BRs at early stage, but decreasing, even lower than that of control in
24 h.
Conclusion: (1) Selective neuron death induced by
prolonged seizure and SE was resulted from necrosis and apoptosis. (2) Significant
processes of necrosis and apoptosis of neurons could be well presented from
early stage, and apoptosis could be getting dominant with time since 12
hours after seizure in ARs. (3) The severity of neuron death in BRs was
much lower than ARs, especially in the process of apoptosis although which
experienced sever SE. It would be indicated that there could be an internal
response physiologically in premature brain after SE to protect neuron
dying, or even to inhibit the process, particularly the process of
apoptosis.