J. Rodrigo et al., SUBCELLULAR-LOCALIZATION OF THE INOSITOL 1,4,5-TRISPHOSPHATE RECEPTOR, P400, IN THE VESTIBULAR COMPLEX AND DORSAL COCHLEAR NUCLEUS OF THE RAT, Brain research, 634(2), 1994, pp. 191-202
The subcellular localization of the inositol 1,4,5-trisphosphate recep
tor protein, P-400, was studied in the vestibular complex, an area to
which Purkinje cells project, as well as in neurons of the dorsal coch
lear nucleus and in ectopic Purkinje cells of adult rat brain. The rec
eptor was demonstrated by electron microscopical immunocytochemistry u
sing the avidin-biotin peroxidase complex procedure, with the monoclon
al antibody 4C11 raised against mouse cerebellar inositol 1,4,5-trisph
osphate receptor protein. Immunoreactivity was found in preterminal fi
bres and terminal boutons in the nuclei of the vestibular complex, gen
erally associated with the subsurface systems and stacks or fragments
of smooth endoplasmic reticulum. Ectopic Purkinje cells and cartwheel
cells of the dorsal cochlear nucleus also displayed immunoreactivity,
but this was much less intense in the latter. The results of the prese
nt study suggest that this receptor protein, involved in the release o
f Ca2+, is located in sites that enable it to influence the synthesis,
transport and release of neurotransmitters.