Gamma-aminobutiric acid immunostaining in trigeminal, nodose and spinal ganglia of the cat.
Gamma-aminobutyric acid (GABA) is a principal inhibitory neurotransmitter in the vertebrate nervous system. It is found mainly in local circuit neurons, but it has also been described in sensory organs and dorsal root ganglia (DRG). The present study describes the presence of GABA in primary afferent neurons of feline sensory ganglia: trigeminal ganglia (TrG), nodose ganglia (NG), and DRG. Quantitative analysis revealed that approximately 20% of the cells in the TrG, NG and DRG are GABAergic. GABA-expressing neurons varied in size. GABA-containing neuronal fibres were also observed in the neuropil. Some of these were in close apposition to both GABA-positive and GABA-negative ganglionic neuronal perikarya. The localization of GABA in small primary afferent neurons, which are considered to be nociceptors, suggests that the amino acid may function as a pain transmitter or modulator, whereas processing of other sensory modalities, such as somatosensory and proprioceptive, may also be affected by GABA.
Stoyanova
Irina I
II
Department of Anatomy, Histology and Embryology, Faculty of Medicine, Thracian University, P.O. Box 1025, Stara Zagora BG-6010, Bulgaria. ir_stoyanova@hotmail.com
D000818:Animals; D002415:Cats; D002452:Cell Count; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009620:Nodose Ganglion / Q000166:cytology / Q000378:metabolism*; D012668:Trigeminal Ganglion / Q000166:cytology / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000032:analysis / Q000378:metabolism*
D005680:gamma-Aminobutyric Acid