title: Survival of mossy cells of the hippocampal dentate gyrus in humans with mesial temporal lobe epilepsy.
abstract: OBJECTIVE
  Hippocampal sclerosis can be identified in most patients with mesial temporal lobe epilepsy (TLE). Surgical removal of the sclerotic hippocampus is widely performed to treat patients with drug-resistant mesial TLE. In general, both epilepsy-prone and epilepsy-resistant neurons are believed to be in the hippocampal formation. The hilar mossy cells of the hippocampal dentate gyrus are usually considered one of the most vulnerable types of neurons. The aim of this study was to clarify the fate of mossy cells in the hippocampus in epileptic humans.
  
  
  METHODS
  Of the 19 patients included in this study, 15 underwent temporal lobe resection because of drug-resistant TLE. Four patients were used as controls because they harbored tumors that had not invaded the hippocampus and they had experienced no seizures. Histological evaluation of resected hippocampal tissues was performed using immunohistochemistry.
  
  
  RESULTS
  Mossy cells were identified in the control as well as the epileptic hippocampi by using cocaine- and amphetamine-regulated transcript peptide immunohistochemistry. In most cases the number of mossy cells was reduced and thorny excrescences were smaller in the epileptic hippocampi than in controls; however, there was a significant loss of pyramidal cells and a partial loss of granule cells in the same epileptic hippocampi in which mossy cell loss was apparent. The loss of mossy cells could be correlated with the extent of hippocampal sclerosis, patient age at seizure onset, duration of epilepsy, and frequency of seizures.
  
  
  CONCLUSIONS
  In many cases large numbers of mossy cells were present in the hilus of the dentate gyrus when most pyramidal neurons of the CA1 and CA3 areas of the Ammon's horn were lost, suggesting that mossy cells may not be more vulnerable to epileptic seizures than the hippocampal pyramidal neurons.
authors.affiliation: Central Electron Microscopic Laboratory University of Pécs, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Seress
authors.forename: Hajnalka
authors.initials: H
authors.lastname: Abrahám
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Horváth
authors.forename: Tamás
authors.initials: T
authors.lastname: Dóczi
authors.forename: József
authors.initials: J
authors.lastname: Janszky
authors.forename: Joyce
authors.initials: J
authors.lastname: Klemm
authors.forename: Richard
authors.initials: R
authors.lastname: Byrne
authors.forename: Roy A E
authors.initials: RA
authors.lastname: Bakay
mesh_terms: D000293:Adolescent; D000328:Adult; D038481:Anterior Temporal Lobectomy; D001932:Brain Neoplasms / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D056547:CA1 Region, Hippocampal / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D056654:CA3 Region, Hippocampal / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D002452:Cell Count; D002470:Cell Survival; D018891:Dentate Gyrus / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D004833:Epilepsy, Temporal Lobe / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000473:pathology / Q000502:physiology*; D017966:Pyramidal Cells / Q000473:pathology / Q000502:physiology / Q000601:surgery; D055815:Young Adult; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein
chemical_list: D009419:Nerve Tissue Proteins; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein