A multi-channel whisker stimulator for producing spatiotemporally complex tactile stimuli

A system is described that delivers complex, biologically realistic, tactil e stimuli to the rat's facial whisker pad by independently stimulating up t o 16 individual facial whiskers in a flexible yet highly controlled and rep eatable manner. The system is technically simple and inexpensive to constru ct. The system consists of an array of 16 miniature-solenoid driven actuato rs that are attached to 16 individual facial whiskers via very small (130 m um dia.) Teflon-coated stainless steel wires. When individual solenoids are energized, the wire is rapidly retracted, resulting in a deflection of ind ividual whiskers. The rise time of deflection is approx. 1 mm/ms. Repeatabl e stimulation of individual whiskers can be achieved without touching adjac ent whiskers, thereby allowing a very high density of stimulators to be att ached within the spatially restricted region of the facial whisker pad. Com plex patterns of whisker stimulation (designed to mimic biologically realis tic stimuli) are delivered to the whisker pad by activating individual sole noid actuators in precisely controlled temporal patterns. These stimulation s can be combined with multi-electrode single-unit ensemble recordings at m ultiple sites within the rat trigeminal somatosensory system. Analysis of n euronal population responses to these complex stimuli is intended to examin e how the trigeminal somatosensory system encodes and processes spatiotempo rally complex stimuli. (C) 2001 Elsevier Science B.V. All rights reserved.