Abstract:
Understanding the joint encoding of multiple tactile stimulus features (e.g., spatial position, amplitude, and frequency of vibration) is a major goal of somatosensory neuroscience, and the development of experimental set-ups to probe joint encoding is important. We describe in detail a microcontroller-based, piezoelectric bender device for tactile experiments. The device comprises an Arduino Due microcontroller board with a 32-bit ARM Cortex-M3 RISC processor, and two 12-bit digital-to-analog converters, enabling precise, independent stimulation of adjacent epithelial points. Using laser doppler vibrometry, we developed a model of the benders' structural mechanics, which we implemented on the device. We used the device to delivered precise, reliable somatosensory stimulation in an experimental setting, recording electrophysiological responses in the peripheral nervous system of the Gisborne cockroach (Drymaplaneta semivitta) to sinusoidal vibration of tibial spines. We plotted tuning curves and derived bandwidths of multi-unit populations. We also stimulated rat facial vibrissae ex vivo. This microcontroller-based, low-cost, open-source system leverages a large developer community associated with Arduino, and may help speed advances in systems neuroscience.
