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
Authors: Suelen Baggio
Kamila Cagliari Zenki
Diogo Onofre de Souza
Gilvan Luiz Borba Filho
Maria Elisa Calcagnotto
Simone Nardin Weis
Eduardo Rigon Zimmer
Eduardo Kalinine
Letícia Pettenuzzo
Journal: PloS one (2015)
Discipline: Multidisciplinary
Keywords: Step-down inhibitory avoidance task; aversive memory; device modification; stainless steel bars; electrical dipole
Affiliations: 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., 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., 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., 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.

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. New method: 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. Result: 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. Conclusion: 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. 

Retracted: No

PubPeer comments:
 PLOS does not permit references to u201cdata not shown.u201d Authors should deposit relevant data in a public data repository or provide the data in the manuscript. https: journals.plos.org plosone s data-availability#:~:text=PLOS%20does%20not%20permit%20references,the%20data%20in%20the%20manuscript. text=Additional%20information%20on%20blot%20and%20gel%20reporting%20requirements%20can%20be%20found%20here. Authors mention u201cdata not shownu201d twice in the article u201cFig 8. Effect of guanosine on the step-down inhibitory avoidance task. (A) Effect of guanosine (i.p.- 7.5mg kg) on the step-down inhibitory avoidance task using 0.35 mA stimuli with different frequencies (62 Hz and 125 Hz). All groups displayed similar escape latency **(data not shown)**.u201d u201cThe learning was observed in the second protocol but not in the first protocol (applied the stimulus for 3s), using 0.35mA 62Hz.However, using current of 0.8mA 62Hz for 3s the animal behavior reflects the classic experiments **(data not show)**. u201c ,