Continuous, multidimensional coding of 3D complex tactile stimuli by primary sensory neurons of the vibrissal system

Significance An animal’s primary sensory neurons (PSNs) translate information about the environment into neural signals that allow perception and action. While much is known about visual and auditory PSN responses to complex stimuli, somatosensory neurons have been characterized with simplified and repeatable stimuli. Thus, knowledge of somatosensory PSN representational capacity remains incomplete. We used the rodent whisker system to examine how tactile mechanical information is represented in PSNs of the trigeminal ganglion (Vg) when the whiskers receive complex three-dimensional stimulation. In contrast to proposed codes in which subpopulations of Vg neurons encode select stimulus features, our results show that individual Vg neurons represent multiple stimulus features in a tiled and continuous manner, thus encoding large regions of a complex sensory space.