title: Characterization of human auditory brainstem circuits by calcium-binding protein immunohistochemistry.
abstract: The cochlear nucleus (CN) and superior olivary complex are auditory brainstem centers with essential roles in encoding temporal features of vocalizations, localization of sound sources and descending modulation of the cochlea. Numerous neuronal populations, across a multitude of laboratory mammals, have been characterized within these brainstem centers based on cell body morphology, dendritic architecture, afferent/efferent connections and neurochemistry. However, scant details are available for these neuronal populations in humans. The objective of this study is to further characterize human auditory hindbrain nuclei and examine the axonal connections between these structures. To this end, we have used immunohistochemistry and morphometric techniques to characterize neuronal populations and axonal projections in the human brainstem. Herein, we provide evidence for calretinin immunoreactive neurons and synaptic boutons in the ventral CN, axons in the trapezoid body, peridendritic boutons in the medial superior olive and calyceal endings in the medial nucleus of the trapezoid body (MNTB). Further, we demonstrate that the majority of neurons in the human MNTB are calbindin and Kv3.1b immunoreactive and that perisomatic profiles in this nucleus are vesicular glutamate transporter and Rab3a positive, suggesting that such profiles are in fact synaptic terminals.
authors.affiliation: Auditory Research Center, Lake Erie College of Osteopathic Medicine, Erie, PA, United States. Electronic address: rkulesza@lecom.edu.
authors.forename: R J
authors.initials: RJ
authors.lastname: Kulesza
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001306:Auditory Pathways / Q000378:metabolism; D001369:Axons / Q000378:metabolism*; D001933:Brain Stem / Q000378:metabolism*; D064032:Calbindin 2 / Q000378:metabolism; D064026:Calbindins / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D017626:Cochlear Nucleus / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D009847:Olivary Nucleus / Q000378:metabolism; D017729:Presynaptic Terminals / Q000378:metabolism; D051637:Shaker Superfamily of Potassium Channels; D051670:Shaw Potassium Channels / Q000378:metabolism; D050496:Vesicular Glutamate Transport Proteins / Q000378:metabolism; D020826:rab3A GTP-Binding Protein / Q000378:metabolism
chemical_list: C576764:CALB2 protein, human; D064032:Calbindin 2; D064026:Calbindins; D002135:Calcium-Binding Proteins; C116766:KCNAB3 protein, human; D009419:Nerve Tissue Proteins; D051637:Shaker Superfamily of Potassium Channels; D051670:Shaw Potassium Channels; D050496:Vesicular Glutamate Transport Proteins; D020826:rab3A GTP-Binding Protein
keywords: AN; CB; CB+; CBP; CN; CR; CR+; GBC; LNTB; LSO; MNTB; MSO; NDS; PB; PV; SBC; SOC; SPON; VCN; VGLUT; auditory nerve; calbindin; calbindin immunopositive; calcium-binding proteins; calretinin; calretinin immunopositive; calyx of held; cochlear nucleus; globular bushy cell; lateral nucleus of the trapezoid body; lateral superior olive; medial nucleus of the trapezoid body; medial superior olive; normal donkey serum; parvalbumin; phosphate buffer; spherical bushy cell; superior olivary complex; superior olive; superior paraolivary nucleus; trapezoid body; tz; ventral cochlear nucleus; vesicular glutamate transporter