title: A new device for step-down inhibitory avoidance task--effects of low and high frequency in a novel device for passive inhibitory avoidance task that avoids bioimpedance variations.
abstract: BACKGROUND
  Step-down inhibitory avoidance task has been widely used to evaluate aversive memory, but crucial parameters inherent to traditional devices that may influence the behavior analysis (as stimulus frequency, animal's bioimpedance) are frequently neglected.
  
  
  METHODS
  We developed a new device for step-down inhibitory avoidance task by modifying the shape and distribution of the stainless steel bars in the box floor where the stimuli are applied. The bars are 2 mm wide, with rectangular shape, arranged in pairs at intervals of 1cm from the next pairs. Each pair makes an electrical dipole where the polarity inverts after each pulse. This device also presents a component that acquires and records the exact current received by the animal foot and precisely controls the frequency of stimulus applied during the entire experiment.
  
  
  RESULTS
  Different from conventional devices, this new apparatus increases the contact surface with bars and animal's paws, allowing the electric current pass through the animal's paws only, drastically reducing the influence of animal's bioimpedance. The analysis of recorded data showed that the current received by the animal was practically the same as applied, independent of the animal's body composition. Importantly, the aversive memory was observed at specific stimuli intensity and frequency (0.35 or 0.5 mA at 62 and 125 Hz but not at 0.20 mA or 20 Hz). Moreover, with this device it was possible to observe the well-known step-down inhibitory avoidance task memory impairment induced by guanosine.
  
  
  CONCLUSIONS
  This new device offers a substantial improvement for behavioral analysis in step-down inhibitory avoidance task and allows us to precisely compare data from different animals with distinct body composition.
authors.affiliation: Programa de Pós-Graduação em Educação em Ciências, ICBS-Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.
authors.forename: Gilvan Luiz
authors.initials: GL
authors.lastname: Borba Filho
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas-Bioquímica, ICBS-Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.
authors.forename: Kamila Cagliari
authors.initials: KC
authors.lastname: Zenki
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas-Bioquímica, ICBS-Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil; Programa de Pós-Graduação em Ciências Fisiológicas-Universidade Federal de Sergipe, São Cristóvão, Sergipe, Brasil.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Kalinine
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas-Bioquímica, ICBS-Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.
authors.forename: Suelen
authors.initials: S
authors.lastname: Baggio
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas-Bioquímica, ICBS-Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.
authors.forename: Letícia
authors.initials: L
authors.lastname: Pettenuzzo
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas-Bioquímica, ICBS-Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.
authors.forename: Eduardo Rigon
authors.initials: ER
authors.lastname: Zimmer
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas-Bioquímica, ICBS-Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.
authors.forename: Simone Nardin
authors.initials: SN
authors.lastname: Weis
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas-Bioquímica, ICBS-Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil; Departamento de Bioquímica, ICBS-Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.
authors.forename: Maria Elisa
authors.initials: ME
authors.lastname: Calcagnotto
authors.affiliation: Programa de Pós-Graduação em Educação em Ciências, ICBS-Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil; Programa de Pós-Graduação em Ciências Biológicas-Bioquímica, ICBS-Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil; Departamento de Bioquímica, ICBS-Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.
authors.forename: Diogo
authors.initials: D
authors.lastname: Onofre de Souza
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D001522:Behavior, Animal / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D017097:Electric Impedance; D004597:Electroshock; D008568:Memory / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar