Through the cerebellum neck information adapts vestibulospinal reflexes to body position. Since the cerebellum controls the reticular formation (RF), we investigated whether neck rotation tunes the labyrinthine responses of the medullary RF neurons. In anesthetized rats, units activity was recorded from the medullary RF during vestibular stimulation (5°, 0.165 Hz) at different body-to-head positions. In a proportion of neurons located in the gigantocellular and magnocellular tegmental RF fields, the response gain increased to 457% of the control value following a 20° rotation of the body towards the recording side, while it decreased to 15% following a 20° contralateral rotation. In a second population of cells the response gain decreased to 69% of the control value following a 20° ipsilateral body rotation, while it increased to 182% following a 20° contralateral rotation. Other neurons showed a bilateral decrease in gain for both directions of rotation. In general, gain changes could not be completely explained by modifications in the unit basal activity. Finally the latter neurons showed also changes in their response direction, much larger then the amplitude of body-to-head rotation. The present results show that within the RF neck afferents modulate the weight of the individual neurons contributions to the coding process of labyrinthine signals and may also induce large changes in the directions of head tilt giving rise to the maximal response of individual neurons.