Memory retention of vestibuloocular reflex motor learning in squirrel monkeys.

The vestibuloocular reflex (VOR) motor learning can be induced chronically by wearing lenses for several weeks to months, or acutely by visual-vestibular mismatch for several hours. Cerebellar long term depression (LTD) has been proposed as a causal mechanism for acute learning. We demonstrate differences in retention of acutely and chronically acquired VOR gains in squirrel monkeys and discuss neuronal correlates and possible roles of cerebellar LTD. Our data is compatible with the idea that cerebellar LTD might be a mechanism responsible for acute VOR adaptation.