5nd National Congress of Neuroscience (V.Ulusal Sinirbilimleri Kongresi, Neuroanatomy Abstract Book, vol.5, pp.24, 2006 (Scopus)
Light and electron microscopic examinations in the hippocampus of the
rat brain following epileptic seizures
Yardimoglu M  , Ilbay G , Kokturk S , Durmaz Onar F , Sahin D
, Alkan F , Dalcik H .
Kocaeli University, Medical Faculty, Department of Histology &
Embryology , Department of Physiology  , Kocaeli; Istanbul University,
Cerrahpasa Medical Faculty, Department of Histology& Embryology ,
Istanbul, Istanbul University, Istanbul Medical Faculty, Department of
Histology & Embryology , Istanbul, Turkey.
The epilepsy worldwide affects more than 50 million people. Epileptic seizures
begin simultaneously and several histopathological changes occur in both
cerebral hemispheres. The changes leads to abnormally increased excitability
and synchronization, and eventually to the occurrence of spontaneous
seizures. Our understanding of the cellular mechanisms underlying epilepsy
remains incomplete. Therefore, we aimmed to evaluate hippocampal neurons
in the rat brain after pentyleneterazol (PTZ)-induced generalized seizures at
microscopically. Male Wistar albino rats were divided into three groups: 1-
acute PTZ group; 2-chronic PTZ group; 3-control group. After experimental
protocols all rats were sacrified and removed brains and processed. Paraffin
sections (5μm) were stained with Toluidin blue and Cresyl fast violet and
examined by light microscopy. For electron microscopy (EM), tissues were
embedded in Vestopal and sections sections were stained with uranyl acetate.
The number of cells was quantified in 765x102 μm2 fields of hippocampal
regions in the X40 objective using a grid for determination of the sampling
volume via Cavalieri method and analyzed using the SPSS statistical software
package and compared using an ANOVA (p<0.05). Ischemic neurons were
observed in the PTZ groups, especially in the chronic epileptic animals.
Histological changes were perikaryal swelling, chromatolysis and decreasing
of Nissl. In EM, necrotic and apoptotic hippocampal neurons were observed
in the PTZ groups. EM revealed that a few dying neurons at the CA1 showed
an apoptotic morphology as described by Portera-Cailliau et al.(1997). These
findings demonstrated a significant decrease in the number of hippocampal
neurons (neuronal loss) in the PTZ-induced epileptic rat groups.
Key words: Epileptic seizures, pentylenetetrazol (PTZ), Nissl, electron
microscopy, rat brain.