Distribution and fine structure of neuronal elements containing glutamate decarboxylase in the rat cochlear nucleus

Distribution and fine structure of gamma-aminobutyric acid (GABA)-containing structures were examined in the rat cochlear nuclear complex by means of immunohistochemistry using glutamate decarboxylase (GAD) as a marker. GAD-like immunoreactive (GADI) terminals were diffusely distributed in the dorsal cochlear nucleus, while in the ventral cochlear nucleus numerous immunoreactive fibers were situated around the cell bodies. These light-microscopic observations were confirmed by electron microscopy. Evidence suggesting that many of GADI boutons in the cochlear nucleus are of intrinsic origin was also shown.