Neuronal dynamics of cerebellum and medial prefrontal cortex in adaptive motor timing

Precise temporal control of sensorimotor coordination and adaptation is a fundamental basis of animal behavior. How different brain regions are involved in regulating the flexible temporal adaptation remains elusive. Here we investigated the neuronal dynamics of cerebellar interposed nucleus (IpN) and medial prefrontal cortex (mPFC) neurons during temporal adaptation between delay eyeblink conditioning (DEC) and trace eyeblink conditioning (TEC). When mice trained for either DEC or TEC and subsequently subjected to a new paradigm, their conditioned responses (CRs) adapted virtually instantaneously. Changes in the activity of the IpN neurons to CR timing were prominent during DEC-to-TEC adaptation, but less so during TEC-to-DEC adaptation. In contrast, mPFC neurons could rapidly alter their modulation patterns during both adaptation paradigms. Accordingly, silencing of mPFC blocked the adaptation of CR timing. These results illuminate how cerebral and cerebellar mechanisms may play differential roles during adaptive control of associative motor timing.