Plasticity and repair of the vestibulo-ocular reflex

It is self-evident, once one thinks about it, that the vestibulo-ocular reflex must have caretaker systems that keep it operating correctly over the span of a lifetime. When a movement is not correct (e.g., in position, speed, direction) it is said to be dysmetric. For the vestibulo-ocular reflex (VOR), if eye velocity is not equal and opposite to head velocity within reasonable limits, one has vestibulo-ocular dysmetria. Consequently, the function of the caretaker systems is to eliminate vestibulo-ocular dysmetria. These systems are first required to act just after birth when the gain of the reflex is usually not normal, and must be initially calibrated; and then maintained as the animal grows older; and then in adult life an important function of the caretaker systems is the compensation required after damage. The mechanisms of this caretaker system and ensuring motor learning is the focus of this chapter.