A Custom Microcontrolled and Wireless-Operated Chamber for Auditory Fear Conditioning

Abstract

Animal behavioral paradigms, such as classical conditioning and operant conditioning, are an important tool to study the neural basis of cognition and behavior. These paradigms involve manipulating sensory stimuli in a way that learning processes are induced under controlled experimental conditions. However, the majority of the commercially available equipment did not offer flexibility to manipulate stimuli. Therefore, the development of most versatile devices would allow the study of more complex cognitive functions. The purpose of this work is to present a low-cost, customized and wireless-operated chamber for animal behavior conditioning, based on the joint operation of two microcontroller modules: Arduino Due and ESP8266-12E. Our results showed that the auditory stimulation system allows setting the carrier frequency in the range of 1 Hz up to more than 100 kHz and the sound stimulus can be modulated in amplitude, also over a wide range of frequencies. Likewise, foot-shock could be precisely manipulated regarding its amplitude (from ∼200 μA to ∼1500 μA) and frequency (up to 20 pulses per second). Finally, adult rats exposed to a protocol of cued fear conditioning in our device showed consistent behavioral response and electrophysiological evoked responses in the midbrain auditory pathway. Furthermore, the device developed in the current study represents an open source alternative to develop customized protocols to study fear memory under conditions of varied sensory stimuli.

A Fully Adapted Headstage With Custom Electrode Arrays Designed for Electrophysiological Experiments

“…A 12-bit digital-to-analog converter at Arduino Due was used to generate the auditory stimuli ( Picton et al, 2003 ; Amaral-Júnior et al, 2019 ). The algorithm behind the tone generation is openly available.…”

“…Via a linear interpolation, these time values were used to obtain an instantaneous phase time series, which in turn was used to reconstruct the signal. This allowed the time-frequency analysis to remain engaged to the auditory stimulation ( Amaral-Júnior et al, 2019 ).…”

Analysis of Main World Trends in Objectivization of Protocols for Behavioral Testing of Laboratory Animals with Brain Pathology

“…Примером удачного дополнения стандартных протоколов нейроповеденческого тестирования современными технологическими решениями является разработка беспроводной системы анализа движений головы животного при проведении контекстного теста на условно-рефлекторный страх: зафиксированная на голове животного система позволяет анализировать время замирания, которое характеризует наличие ассоциативной памяти, регистрируемой в этом тесте, что повышает пространственное разрешение в контексте детекции freezing time [33]. Не менее интересным является решение, связанное с разработкой усовершенствованной камеры для проведения контекстного теста на условно-рефлекторный страх с прецизионной установкой параметров электрического шока, звука и света, что повышает воспроизводимость результатов тестирования животных [1].…”

Extracting electromyographic signals from multi-channel local-field-potentials using independent component analysis without direct muscular recording

“…The LFPs and EMGs of the ten animals were recorded while exploring in the open field chamber (70 cm × 38 cm) for 0.5 to 2 hours. Subsequently, five out of the ten animals were recorded under tone fear conditioning task using a custom-made fear conditioning box [38]. The box consists of a 30 cm × 25 cm × 25 cm transparent acrylic box surrounded by white plastic boards, and 3 mm diameter stainless steel bars with a 6.66 mm pitch on the floor.…”