title: Ultrastructural changes to rat hippocampus in pentylenetetrazol- and kainic acid-induced status epilepticus: A study using electron microscopy.
abstract: A pentylenetetrazol (PTZ)-induced status epilepticus model in rats was used in the study. The brains were studied one month after treatment. Ultrastructural observations using electron microscopy performed on the neurons, glial cells, and synapses, in the hippocampal CA1 region of epileptic brains, demonstrated the following major changes over normal control brain tissue. (i) There is ultrastructural alterations in some neurons, glial cells and synapses in the hippocampal CA1 region. (ii) The destruction of cellular organelles and peripheral, partial or even total chromatolysis in some pyramidal cells and in interneurons are observed. Several astrocytes are proliferated or activated. Presynaptic terminals with granular vesicles and degenerated presynaptic profiles are rarely observed. (iii) The alterations observed are found to be dependent on the frequency of seizure activities following the PTZ treatment. It was observed that if seizure episodes are frequent and severe, the ultrastructure of hippocampal area is significantly changed. Interestingly, the ultrastructure of CA1 area is found to be only moderately altered if seizure episodes following the status epilepticus are rare and more superficial; (iv) alterations in mitochondria and dendrites are among the most common ultrastructural changes seen, suggesting cell stress and changes to cellular metabolism. These morphological changes, observed in brain neurons in status epilepticus, are a reflection of epileptic pathophysiology. Further studies at the chemical and molecular level of neurotransmitter release, such as at the level of porosomes (secretory portals) at the presynaptic membrane, will further reveal molecular details of these changes.
authors.affiliation: Institute of Chemical Biology, Ilia State University, 3/5 K. Cholokhashvili Avenue, 0162 Tbilisi, Georgia; Department of Brain Ultrastructure and Nanoarchitecture, I. Beriitashvili Center of Experimental BioMedicine, 14, Gotua Street, 0160 Tbilisi, Georgia. Electronic address: mzia_zhvania@iliauni.edu.ge.
authors.forename: Mzia G
authors.initials: MG
authors.lastname: Zhvania
authors.affiliation: Institute of Chemical Biology, Ilia State University, 3/5 K. Cholokhashvili Avenue, 0162 Tbilisi, Georgia. Electronic address: mari.qsovreli@yahoo.com.
authors.forename: Mariam
authors.initials: M
authors.lastname: Ksovreli
authors.affiliation: Department of Brain Ultrastructure and Nanoarchitecture, I. Beriitashvili Center of Experimental BioMedicine, 14, Gotua Street, 0160 Tbilisi, Georgia; New Vision University, 1A Evgeni Mikeladze Street, 0158 Tbilisi, Georgia. Electronic address: japaridze.nadia@gmail.com.
authors.forename: Nadezhda J
authors.initials: NJ
authors.lastname: Japaridze
authors.affiliation: Institute of Chemical Biology, Ilia State University, 3/5 K. Cholokhashvili Avenue, 0162 Tbilisi, Georgia; Department of Brain Ultrastructure and Nanoarchitecture, I. Beriitashvili Center of Experimental BioMedicine, 14, Gotua Street, 0160 Tbilisi, Georgia. Electronic address: tamar_lortkipanidze@iliauni.edu.ge.
authors.forename: Tamar G
authors.initials: TG
authors.lastname: Lordkipanidze
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000648:ultrastructure; D003712:Dendrites / Q000648:ultrastructure; D006624:Hippocampus / Q000187:drug effects* / Q000503:physiopathology / Q000648:ultrastructure*; D007608:Kainic Acid; D008297:Male; D008854:Microscopy, Electron / Q000379:methods*; D008928:Mitochondria / Q000648:ultrastructure; D009457:Neuroglia / Q000648:ultrastructure; D009474:Neurons / Q000648:ultrastructure; D010433:Pentylenetetrazole; D017729:Presynaptic Terminals / Q000187:drug effects / Q000648:ultrastructure; D051381:Rats; D013226:Status Epilepticus / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology; D013569:Synapses / Q000648:ultrastructure; D009435:Synaptic Transmission
chemical_list: D007608:Kainic Acid; D010433:Pentylenetetrazole
keywords: Hippocampal CA1 area; Pentylenetetrazol-induced status epilepticus; Rat; Ultrastructure of neurons, synapses and glial cells