Understanding what are the mechanisms that strengthen, stabilize and restrict synaptic innervation is a relevant topic in glutamate receptor delta 2 (GluRdelta2)-related research. It also involves targeting and selection of afferent input during formation of the neuronal circuitry in the cerebellar cortex and its functioning. This review will focus on the role of GluRdelta2, one of the main players in this field. Special emphasis will be placed on the processes that regulate the rapid translocation from climbing fibres to parallel fibres of GluRdelta2 and the role of GluRdelta2 in the reduction of supernumerary climbing fibre contacts on a single Purkinje cell. Furthermore, GluRdelta2 knockout mice show ataxia and impaired motor coordination, suggesting that the presence of GluRdelta2 plays an important role in controlling cerebellar functioning.