Gaba as an afferent neurotransmitter in the vestibular sensory periphery of vertebrates.

The main criteria asked to a GABAergic synapse, have been fulfilled by GABA at the recepto-neural junction of the sensory periphery of vestibular organs in vertebrates. These criteria include the demonstration of its precursor, its synthesizing and degrading (inactivating) mechanisms and their localization with the right polarity of a GABAergic synapse. A novel GABA depolarizing action with particular pharmacological characteristics and expression of subunits of GABA receptors of the synaptic type (GABAA, GABAB or a putative mixed GABAA-GABAC) that could account for these properties are discussed.