GABAergic terminals in nucleus magnocellularis and laminaris originate from the superior olivary nucleus

J Comp Neurol. 1994 Oct 15;348(3):403-18. doi: 10.1002/cne.903480307.


The auditory brainstem nuclei, angularis (NA), magnocellularis (NM), and laminaris (NL) of the chicken, Gallus, contain terminals that stain for antibodies against the inhibitory neurotransmitter, gamma-aminobutyric acid (GABA). Some of these terminals originate from cells surrounding nucleus magnocellularis. Results from this study indicate that the majority of the GABAergic terminals found in NA, NM and NL originate from the superior olivary nucleus (SON). Injections of cholera toxin and horseradish peroxidase show that superior olivary nucleus (SON) neurons, which respond to pure tones, project bilaterally to NA, NM, and NL. NA and NL are reciprocally connected with the SON. More NA cells project to the SON than NL cells. While SON neurons project to NM, NM neurons do not project axons back to the SON. The configuration of SON terminals in NA, NM and NL matches the pattern of GABA-immunoreactive puncta seen in these three nuclei: they surround individual NM cells, congregate in the dendritic neuropil of NL, and blanket the NA. The data indicate that NA, NM and NL may be affected by two different inhibitory cell types: local interneurons and SON neurons. Patterns of connectivity described in this report suggest that the activity of NA cells could influence NM and NL cell physiology. Specifically, increases in NA cell activity could augment the effects of GABAergic SON neurons on NM and NL. Hence, binaural perception in the chicken may be more dependent upon changes in intensity cues than previously believed.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acoustic Stimulation
  • Animals
  • Auditory Pathways / cytology
  • Auditory Pathways / physiology
  • Auditory Pathways / ultrastructure
  • Basal Ganglia / cytology*
  • Basal Ganglia / physiology
  • Basal Ganglia / ultrastructure
  • Brain Stem / physiology
  • Brain Stem / ultrastructure
  • Cell Size
  • Chickens / anatomy & histology*
  • Cholera Toxin
  • Horseradish Peroxidase
  • Immunohistochemistry
  • Nerve Endings / physiology*
  • Nerve Endings / ultrastructure
  • Neurons / physiology
  • Neurons / ultrastructure
  • Olivary Nucleus / cytology*
  • Olivary Nucleus / physiology
  • Olivary Nucleus / ultrastructure
  • Tissue Fixation
  • gamma-Aminobutyric Acid / physiology*


  • gamma-Aminobutyric Acid
  • Cholera Toxin
  • Horseradish Peroxidase