Sensory Inflow from Whiskers Modulates Development of Absence Epilepsy in WAG/Rij Rats

Whisker sensory system plays crucial role in development of brain functions in rats. In WAG/Rij rats with genetic predisposition to absence epilepsy, the area of whiskers’ projection in the somatosensory cortex (barrelfield) is known to contain hyperexcitable neurons which form epileptic focus. Neonatal period of development (PN1–8) is critical for development of whisker sensory system. Whisker deafferentaion during this period causes irreversible plastic changes that considerably impact brain functions in adulthood. Bilateral trimming of all whiskers in WAG/Rij rats during PN1–8 affected seizure activity between 5 and 9 months of age. First, it prevented age-related increase in the number of seizures, suggesting consistency of epileptic activity in the cortical focal zone; second, it prevented age-related increase in seizure duration, suggesting consistency of thalamo-cortical synchronization. Unilateral whisker trimming on PN1–8 increased excitability of pyramidal cells in the intact barrelfild mediated by HCN-related processes.