Journal of Neuroscience, Vol 7, 1843-1856, Copyright © 1987 by Society for Neuroscience
Calcium binding protein-like immunoreactivity labels the terminal field of nucleus laminaris of the barn owl
TT Takahashi, CE Carr, N Brecha and M Konishi
Nucleus laminaris (NL) is the site at which the timing of sounds arriving
in the 2 ears is compared in the auditory system of the barn owl. Earlier
studies have reported vitamin D-dependent calcium binding protein
(CaBP)-like immunoreactivity in the somata of NL. We report here that
CaBP-like immunoreactivity stains the terminal field of NL. The specific
CaBP immunoreactivity is localized to a dense plexus of fibers that have
bouton-like swellings, usually around unstained somata. This type of
immunoreactivity is found in a restricted portion of the central nucleus of
the inferior colliculus (ICc), in the anterior division of the ventral
lateral lemniscal complex (VLVA), and in the superior olivary nucleus (SO),
all of which have been shown by anterograde transport of 3H-proline to be
innervated by NL. The immunoreactivity is absent from the posterior
division of ventral lateral lemniscal complex and from the region that
surrounds the portion of ICc innervated by NL. A restricted lesion in NL
results in a localized deficit in immunoreactivity in those regions of ICc
and VLVA that are known to be innervated by the lesioned area of NL. In
adjacent sections processed by the Fink-Heimer method, degenerating axons
are present in the region of the deficit in immunoreactivity.