title: Systemic administration of polyaminergic agents modulate fear conditioning in rats.
abstract: BACKGROUND
  The polyamines putrescine, spermine, and spermidine are a group of aliphatic amines that physiologically modulate the N-methyl-D-aspartate (NMDA) receptor, a glutamate receptor implicated in memory formation.
  
  
  OBJECTIVE
  Given the potential application of these drugs in the treatment of memory disorders, we investigated whether agonists and/or antagonists of the NMDA receptor polyamine binding site alters the memory of fear conditioning and determined the time window in which fear conditioning is modulated by polyaminergic agents given by the systemic route.
  
  
  RESULTS
  Post-training intraperitoneal administration of spermidine (10-100 mg/kg) immediately after training increased, whereas arcaine (10 mg/kg) and MK-801 (0.01-0.1 mg/kg) decreased contextual and auditory fear conditioning. Arcaine and MK-801, at doses that had no effect per se, reversed the facilitatory effect of spermidine. Memory of fear conditioning was impaired by polyaminergic blockade up to 180 min but not at 360 min after training.
  
  
  CONCLUSIONS
  These results provide evidence that systemic administration of polyamine binding site ligands modulate early consolidation of fear conditioning.
authors.affiliation: Laboratório de Neurotoxicidade e Psicofarmacologia, Centro de Ciências Naturais e Exatas, Departamento de Química, Universidade Federal de Santa Maria, Santa Maria, 97105-900 RS, Brazil.
authors.forename: Keli
authors.initials: K
authors.lastname: Camera
authors.forename: Carlos Fernando
authors.initials: CF
authors.lastname: Mello
authors.forename: Ana Paula Chiapinotto
authors.initials: AP
authors.lastname: Ceretta
authors.forename: Maribel Antonello
authors.initials: MA
authors.lastname: Rubin
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001645:Biguanides / Q000008:administration & dosage / Q000494:pharmacology*; D003214:Conditioning, Classical / Q000187:drug effects*; D016291:Dizocilpine Maleate / Q000008:administration & dosage / Q000494:pharmacology*; D005239:Fear / Q000187:drug effects* / Q000502:physiology; D007274:Injections, Intraperitoneal; D008297:Male; D008568:Memory / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000819:agonists / Q000037:antagonists & inhibitors; D013095:Spermidine / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D001645:Biguanides; D016194:Receptors, N-Methyl-D-Aspartate; C006624:arcaine; D016291:Dizocilpine Maleate; D013095:Spermidine