Immunocytochemical evidence for the GABAergic innervation of the stretch receptor neurons in crayfish

Neuroscience. 1987 Sep;22(3):1111-22. doi: 10.1016/0306-4522(87)92986-1.


The GABAergic innervation of the stretch receptor neurons of the crayfish Orconectes limosus has been investigated by means of light- and electron microscope immunocytochemistry using an antibody to GABA. Both whole-mount preparations and post-embedding semithin sections revealed a massive GABAergic innervation of both the slowly and the fast adapting receptor neurons. The stretch receptor organ is supplied by one principle GABA-immunoreactive axon, which gives off several branches that innervate the receptor neurons. Cell body, initial axon segment and dendritic region of the sensory neurons are covered by numerous GABA-immunoreactive varicose fibers. Electron microscopy revealed that the GABA-immunoreactive varicosities establish specialized synaptic contacts with the sensory neurons. The functional significance of the occurrence of GABA-immunoreactive varicosities on the different parts of the sensory neurons is discussed. The results support the physiological and pharmacological evidence that GABA is a transmitter substance of the efferent inhibitory neurons which innervate the crayfish stretch receptor neurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astacoidea / physiology*
  • Immunohistochemistry
  • Mechanoreceptors / analysis*
  • Mechanoreceptors / ultrastructure
  • Microscopy, Electron
  • Neurons / analysis
  • Neurons / classification
  • Neurons / ultrastructure
  • gamma-Aminobutyric Acid / analysis*


  • gamma-Aminobutyric Acid