Disruption in Patterning in the Whisker-to-Barrel Cortex Pathway Alters Behavior

Mice use their whiskers to convey sensory information, navigate and explore their environment. We investigated the behavioral impact of the disruption of somatotopic patterning along the whisker-to-barrel pathway utilizing two mouse models: Barrelless (BRL) mice, an adenylyl cyclase 1 variation, in which somatotopic patterning is absent in the barrel cortex and Prrxl1-/- mice, a genetic knockout in which patterning is disrupted along the entire lemniscal pathway. A textured novel object recognition test was conducted to investigate whisker-dependent discriminatory behavior, an open field test was conducted to investigate exploratory behavior. Results were compared to an outbred strain (CD-1) and demonstrated that BRL mice were able to discriminate, whereas Prrxl1-/- mice were unable to discriminate between textures, and that both strains exhibited increased anxiety. Exploratory and locomotor behavior increased in BRL mice but decreased in Prrxl1-/- mice. Together, the results suggest that somatotopy may be related to behavioral phenotype.