BDNF and NT-4, but not NT-3, promote development of inhibitory synapses in the absence of neuronal activity.

Development of the full complement of inhibitory synapses in cerebellar cultures requires the presence of neuronal activity. The neurotrophins, BDNF, NT-3 and NT-4, were applied to cerebellar explants during activity blockade. Control numbers of inhibitory Purkinje cell axosomatic synapses developed in the presence of the TrkB receptor ligands, BDNF and NT-4, but not the TrkC receptor ligand, NT-3. The results suggest that BDNF and NT-4 have a role in the promotion of activity-dependent inhibitory synaptogenesis.