Patterns of calcium-binding proteins in human inferior colliculus: identification of subdivisions and evidence for putative parallel systems

• Published in: Neuroscience 2003-01, Vol.116 (4), p.1111-1121
• Main Authors: Tardif, E, Chiry, O, Probst, A, Magistretti, P.J, Clarke, S
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; auditory pathways; Biological and medical sciences; calbindin; Calcium-Binding Proteins - analysis; Calcium-Binding Proteins - biosynthesis; calretinin; Ear and associated structures. Auditory pathways and centers. Hearing. Vocal organ. Phonation. Sound production. Echolocation; Female; Fundamental and applied biological sciences. Psychology; Humans; Inferior Colliculi - chemistry; Inferior Colliculi - cytology; Inferior Colliculi - metabolism; Male; mid-brain; Neurons - chemistry; Neurons - cytology; Neurons - metabolism; parvalbumin; tectum; Vertebrates: nervous system and sense organs
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/S0306-4522(02)00774-1

The subdivisions of human inferior colliculus are currently based on Golgi and Nissl-stained preparations. We have investigated the distribution of calcium-binding protein immunoreactivity in the human inferior colliculus and found complementary or mutually exclusive localisations of parvalbumin versus calbindin D-28k and calretinin staining. The central nucleus of the inferior colliculus but not the surrounding regions contained parvalbumin-positive neuronal somata and fibres. Calbindin-positive neurons and fibres were concentrated in the dorsal aspect of the central nucleus and in structures surrounding it: the dorsal cortex, the lateral lemniscus, the ventrolateral nucleus, and the intercollicular region. In the dorsal cortex, labelling of calbindin and calretinin revealed four distinct layers. Thus, calcium-binding protein reactivity reveals in the human inferior colliculus distinct neuronal populations that are anatomically segregated. The different calcium-binding protein-defined subdivisions may belong to parallel auditory pathways that were previously demonstrated in non-human primates, and they may constitute a first indication of parallel processing in human subcortical auditory structures.