Peripheral neurons innervating semicircular canals can respond to constant linear accelerations. Evidence is presented that, in our preparation, the response is artifactual and arises from thermal gradients introduced by the surgical exposure. Otolith neurons do not respond to even intense angular accelerations. Canal plugging abolishes the response of the corresponding afferents to angular acceleration, without obviously affecting resting activity. The procedure does not prevent the canals from responding to linear accelerations. The latter response, unlike that seen in intact canals, is not due to thermal gradients and may be related to the mechanisms underlying the persistent component of barbecue nystagmus.