title: Maximal electroshock-induced seizures are able to induce Homer1a mRNA expression but not pentylenetetrazole-induced seizures.
abstract: OBJECTIVE
  Homer1a is a protein that regulates metabotropic glutamate receptors involved in neural plasticity processes. Recently, we demonstrated that Homer1a mRNA is enhanced after pilocarpine-induced status epilepticus. Here, we investigated whether a single acute seizure triggered by means of pentylenetetrazole (PTZ) injection or maximal electroshock (MES) stimulation (2 different seizure models) would alter Homer1a expression in the hippocampus.
  
  
  METHODS
  Male Wistar rats subjected to the PTZ or MES model were analyzed 2h, 8h, 24h, and 7days after seizure induction. Homer1a, mGluR1, and mGluR5 mRNA expression levels in hippocampal extracts were analyzed by quantitative PCR.
  
  
  RESULTS
  Quantitative PCR revealed Homer1a overexpression at 2h after MES-induced tonic-clonic seizures compared to control, but the overexpression did not remain elevated after 8h. Pentylenetetrazole-induced seizures, in contrast, were not able to change Homer1a mRNA expression. No differences were observed at these time points after seizures for mGluR1 and mGluR5 mRNA expression in any of the models.
  
  
  CONCLUSIONS
  Our data indicate that the levels of Homer1a mRNA were transiently increased only after MES-induced tonic-clonic seizures (and not after PTZ-induced seizures). We suggest that Homer1a expression may be dependent on seizure intensity or on specific brain circuit activation. We suggest that Homer1a may contribute to counteract hyperexcitability processes.
authors: Department of Physiology, Universidade Federal de São Paulo, Pedro de Toledo St, 669, 3rd floor, 04039-032 São Paulo, SP, Brazil.
authors: Clarissa F
authors: CF
authors: Cavarsan
authors: UNONEX, Department of Microbiology, Immunology, and Parasitology, Universidade Federal de São Paulo, Building Prof. Dr. Antonio C. Mattos Paiva, Botucatu St, 862, 8th floor, Vila Clementino, 04023-062 São Paulo, SP, Brazil.
authors: Alisson
authors: A
authors: Matsuo
authors: Department of Physiology, Universidade Federal de São Paulo, Pedro de Toledo St, 669, 3rd floor, 04039-032 São Paulo, SP, Brazil.
authors: Miriam M
authors: MM
authors: Blanco
authors: Department of Physiology, Universidade Federal de São Paulo, Pedro de Toledo St, 669, 3rd floor, 04039-032 São Paulo, SP, Brazil. Electronic address: lemello@unifesp.br.
authors: Luiz E
authors: LE
authors: Mello
mesh_terms: D000818:Animals; D000927:Anticonvulsants / Q000627:therapeutic use; D002352:Carrier Proteins / Q000378:metabolism*; D003292:Convulsants / Q000494:pharmacology*; D004195:Disease Models, Animal; D004597:Electroshock / Q000379:methods*; D000072233:Homer Scaffolding Proteins; D008297:Male; D010433:Pentylenetetrazole / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate; D012640:Seizures / Q000139:chemically induced / Q000209:etiology / Q000378:metabolism*
chemical_list: D000927:Anticonvulsants; D002352:Carrier Proteins; D003292:Convulsants; D000072233:Homer Scaffolding Proteins; D012333:RNA, Messenger; D018094:Receptors, Metabotropic Glutamate; C104077:metabotropic glutamate receptor type 1; D010433:Pentylenetetrazole
keywords: Homer1a; Immediate early gene; Maximal electroshock; Pentylenetetrazole; Rats; Seizure