Redirected oral behavior in rats induced by tail-pinch and electrical stimulation of the tail

Two seemingly non-specific stimuli, tail-pinch and electrical stimulation of the tail (EST), produce different responses to food in rats: tail-pinch induces eating whereas EST elicits licking of food pellets. However, even if administered several months earlier, prior tail-pinch changes the response to pellets during EST from licking to eating. If their tail is within reach, naive rats lick it rather than food pellets. However, they rarely pursue the tail after their initial attempts to reach it are prevented; instead, they eat or lick food. In fact, if they have prior tail-pinch experience, they first eat during EST even with the tail in sight and reach. Thus the response to tail stimulation is directed specifically at the tail and is redirected towards food when the tail is not available. Different oral responses during tail-pinch and EST suggest that the two stimuli induce different sensations; however, the redirected response is modifiable by learning.