New ultrastructural features in the vestibular labyrinth of the toadfish, Opsanus tau.

Electron microscopy of the toadfish vestibular labyrinth demonstrated the usual cytoarchitectural efferent-hair cell organization with type II hair cells having efferent synaptic terminals directly onto the hair cell bodies. Additional, unexpected findings were: direct efferent-afferent synapses; and two types of synaptic vesicles either found both in the same efferent terminals or in two separate classes of efferent terminals.