The distribution of GABA and glycine immunostaining in the cochlear nucleus of the mustached bat (Pteronotus parnellii).
The distribution of neuronal elements immunoreactive for gamma-aminobutyric acid (GABA) and glycine in the cochlear nucleus of the mustached bat Pteronotus parnellii has been studied by means of the postembedding technique on serial semithin sections. Our goal has been to identify similarities and differences in the organization of putatively inhibitory circuits between a highly specialized echolocating bat and previously studied non-echolocating mammals. The results reveal a basically conserved pattern of putatively GABAergic and glycinergic elements in the bat cochlear nucleus, and subtle but distinct modifications in certain inhibitory circuits. As in other mammals, immunoreactive cells possibly representing local interneurons are most abundant in the dorsal cochlear nucleus. These include single-GABA-immunoreactive cells and double-labeled cells in the superficial layers and single-glycine-labeled cells in the deep layers. Coincident with the phylogenetic trend toward a reduced lamination of the dorsal cochlear nucleus in bats, there is a clear reduction in the numbers of local interneurons of the superficial layer. In contrast, the tuberculoventral system of the deep layer appears hypertrophied. As in other mammals, the ventral cochlear nucleus contains a few large single-glycine-immunoreactive cells and scattered double-labeled cells. Immunoreactive puncta are abundant throughout the cochlear nucleus complex with no trends indicating a differential strength of inhibitory inputs to regions representing the various harmonics of the echolocating signal.
Kemmer
M
M
Institut für Zoologie, Universität Regensburg, Universitätsstrasse 31, D-93040 Regensburg, Germany.
Vater
M
M
D000818:Animals; D000918:Antibody Specificity; D001306:Auditory Pathways; D048429:Cell Size / Q000502:physiology; D002685:Chiroptera; D017626:Cochlear Nucleus / Q000737:chemistry* / Q000166:cytology; D005998:Glycine / Q000032:analysis* / Q000276:immunology; D007150:Immunohistochemistry; D009433:Neural Inhibition / Q000502:physiology; D009434:Neural Pathways; D009474:Neurons / Q000166:cytology / Q000648:ultrastructure; D005680:gamma-Aminobutyric Acid / Q000032:analysis* / Q000276:immunology
D005680:gamma-Aminobutyric Acid; D005998:Glycine