The question of whether error signals carried by climbing fibers are the trigger for learning has been controversial, since the evidence from different studies has been inconsistent.
The error signals carried by climbing fibers during VOR-increase and VOR-decrease training should trigger reductions in Purkinje cell output during ipsiversive and contraversive vestibular stimuli, respectively.
These results raised the possibility that the efficacy of the error signals carried by climbing fibers to induce plasticity is reduced during VOR-decrease training.
Our results provide some of the strongest evidence to date that error signals carried by the climbing fibers drive VOR-increase learning.
However, the equally robust error signals carried by the climbing fibers during VOR-decrease training seem to make little or no contribution to the induction of learning.
The results of our trial-by-trial analysis suggest that error signals carried by climbing fibers contribute to the induction of plasticity during VOR-increase but not during VOR-decrease training.
However, to date, there has been no evidence about whether the ability of the error signals carried by climbing fibers to induce learning is also regulated in awake, behaving animals.
Left, to mimic error signals carried by climbing fibers during visual-vestibular VOR-increase or VOR-decrease training (see Figure 2A F ), we optogenetically activated floccular climbing fibers during the ipsiversive phase (CF stim + Ipsi Vestibular, red) or contraversive phase (CF stim + Contra Vestibular, blue) of a 1 Hz sinusoidal vestibular stimulus (black).
Thus, there should be cerebellar synapses coactive with the climbing fibers during both training paradigms, and therefore some other aspect of the state of the cerebellar circuit is more likely to be regulating the ability of the error signals carried by climbing fibers to induce plasticity.
In contrast, a community survey about medical errors carried out by the European Commission showed that 23% of the patients or their family member had encountered a medical error [ 36].
