Light and electron microscopic examinations in the hippocampus of the rat brain following epileptic seizures


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Yardımoğlu Yılmaz M., İlbay G., Köktürk S., Durmaz Onar F., Şahin D., Alkan F., ...More

5nd National Congress of Neuroscience (V.Ulusal Sinirbilimleri Kongresi, Neuroanatomy Abstract Book, vol.5, pp.24, 2006 (Scopus)

Abstract

P26

Light and electron microscopic examinations in the hippocampus of the

rat brain following epileptic seizures

Yardimoglu M [1] , Ilbay G [2], Kokturk S [3], Durmaz Onar F [4], Sahin D

[2], Alkan F [3], Dalcik H [1].

Kocaeli University, Medical Faculty, Department of Histology &

Embryology [1], Department of Physiology [2] , Kocaeli; Istanbul University,

Cerrahpasa Medical Faculty, Department of Histology& Embryology [3],

Istanbul, Istanbul University, Istanbul Medical Faculty, Department of

Histology & Embryology [4], Istanbul, Turkey.

docdrmelda@yahoo.com

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.