Ultrastructural characterization of gerbil olivocochlear neurons based on differential uptake of /sup 3/H-D-aspartic acid and a wheatgerm agglutinin-horseradish peroxidase conjugate from the cochlea

Journal Article · Thu Sep 01 00:00:00 EDT 1988 · J. Neurosci.; (United States)

OSTI ID:6558677

Helfert, R H; Schwartz, I R; Ryan, A F

Two populations of olivocochlear (OC) neurons have been identified in the gerbil brain stem on the basis of differential labeling patterns of 3H-D-aspartic acid (D-ASP) and wheatgerm agglutinin-horseradish peroxidase conjugate (WGA/HRP) from the cochlear perilymph. While both populations are capable of uptake and retrograde uptake of WGA/HRP, one population accumulates and retrogradely transports D-ASP (D-ASP OC neurons) and the other does not (non-D-ASP OC neurons). D-ASP OC neurons are found in or near the lateral superior olive, are small in size, and receive very few synaptic contacts. The vast majority of these synapses contain small, mildly pleomorphic vesicles with scattered dense core vesicles. Synapses with distinctly larger pleomorphic vesicles have also been observed. These neurons possess all of the features common to neurons of the lateral olivocochlear system. Non-D-ASP OC neurons are found primarily in the ventral nucleus of the trapezoid body, as well as in the area between the medial superior olive and the medial nucleus of the trapezoid body. These neurons are larger and receive greater numbers and types of synaptic contacts than those found on D-ASP OC neurons. The 2 most common synapses found on non-D-ASP OC neurons are axosomatic ones containing small, mildly pleomorphic vesicles and scattered dense core vesicles similar to those seen on the D-ASP OC neurons, and axodendritic synapses containing large, round vesicles. Much less frequently observed are synapses containing small, round vesicles or ones containing predominantly flat vesicles. The ultrastructural features of the non-D-ASP OC neurons correspond to those described for neurons of the medial olivocochlear system.

• OSTI ID: 6558677
• Journal Information: J. Neurosci.; (United States), Vol. 8:9
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
AUDITORY ORGANS
PHYSIOLOGY
NERVE CELLS
CHEMICAL COMPOSITION
PEROXIDASES
UPTAKE
ASPARTIC ACID
GERBILS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
AMINO ACIDS
ANIMAL CELLS
ANIMALS
BODY
CARBOXYLIC ACIDS
ENZYMES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
OXIDOREDUCTASES
RODENTS
SENSE ORGANS
SOMATIC CELLS
VERTEBRATES
551001* - Physiological Systems- Tracer Techniques