Research overview: trigeminal innervation of the whisker system

Whisker signals travel to the brain through the trigeminal nerve, and the cat has served as a model for studying this tactile pathway. This overview surveys how densely the whisker follicles are innervated and how their signals are relayed through trigeminal nuclei to the thalamus and somatosensory cortex. The heavy innervation underlies the high sensitivity and resolution of the whisker sense. The survey relates the pathway to the cortical representation of the whiskers, where the orderly facial array is mapped onto the brain. It discusses how this organization allows the cat to localize and interpret contacts on specific whiskers. Understanding trigeminal innervation links the peripheral follicle-sinus complexes to central processing, completing the circuit from whisker deflection to perception. It shows that the whisker sense is supported by a substantial neural investment, reflecting its importance for navigation and hunting in the cat's life.