Navigation is a complex process involving sensorimotor computation, where the brain integrates sensory information in allocentric and egocentric coordinates to formulate a motor plan for effective navigation. In low-light conditions, rodents heavily rely on their whiskers for tactile sensing to guide their movements. While prior research has shown that rodents can utilize whisker input for mobility early in postnatal development, the timeline and mechanisms of adaptive sensorimotor control of whisker position remain unclear. This study longitudinally investigated the maturation of sensorimotor control in rats as they searched for a stationary target in darkness. The findings reveal that juvenile rats initially control their body, not whisker position, based on the anticipated target location. Adaptive, closed-loop control of whisker position develops only after the third postnatal week. Computational modeling indicates that the emergence of closed-loop control and reactive retraction (ensuring constant tactile sampling duration) contributes to the maturation of sensorimotor exploration strategies during active sensing. These results suggest a sequential development of adaptive motor control for the body and whiskers, with sensorimotor control of whisker position emerging later in postnatal development upon the maturation of intracortical sensorimotor circuits.
Development of adaptive motor control for tactile navigation
Alireza Azarfar,