A somatotopic map of vibrissa motion direction within a barrel column.
Most mammals possess high-resolution visual perception, with primary visual cortices containing fine-scale, inter-related feature representations (for example, orientation and ocular dominance). Rats lack precise vision, but their vibrissa sensory system provides a precise tactile modality, including vibrissa-related 'barrel' columns in primary somatosensory cortex. Here, we examined the subcolumnar organization of direction preference and somatotopy using a new omni-directional, multi-vibrissa stimulator. We discovered a direction map that was systematically linked to somatotopy, such that neurons were tuned for motion toward their preferred surround vibrissa. This sub-barrel column direction map demonstrated an emergent refinement from layer IV to layer II/III. These data suggest that joint processing of multiple sensory features is a common property of high-resolution sensory systems.
Harvard Program in Biophysics, Medical School Campus, Building C-2 Room 122, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
Mark L
ML
Andermann
Christopher I
CI
Moore
D000818:Animals; D001931:Brain Mapping; D004558:Electric Stimulation; D008297:Male; D008953:Models, Anatomic; D009039:Motion Perception / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013003:Somatosensory Cortex / Q000033:anatomy & histology / Q000502:physiology; D014738:Vibrissae / Q000378:metabolism*