Whisker-Mediated Texture Discrimination Learning in Freely Moving Mice

摘要

Texture is often used as a convenient stimulus dimension to study aspects of discrimination learning in rodents. However, the basis of texture discrimination learning is often left untested: Although learning could involve the whisker system, it could also be based on other senses (e.g., olfactory or visual). Here, we investigated whether mice use their whisker system to learn texture discriminations. Mice were placed in an apparatus illuminated with a dim red light, and the mice had to learn which of 2 sawdust-filled bowls contained a buried reward. The outer surfaces of the bowls were 3-D printed with different textures (grooved or smooth). Within a 60-min session, mice learned to dig in 1 bowl (e.g., grooved) rather than the other (e.g., smooth) to gain the reward. This texture discrimination and an equivalent odor discrimination were retained overnight (Experiments 1 and 2); and whisker trimming disrupted learning based on the texture of the bowls but not learning based on the odor of the sawdust in the bowls (Experiments 3 and 4). These results provide a secure basis upon which to investigate the behavioral and brain basis of texture learning in rodents.