GABA and glutamate-like immunoreactivity at synapses on depressor motorneurones of the leg of the crayfish, Procambarus clarkii.
To investigate their synaptic relationships, depressor motorneurones of the crayfish leg were impaled with microelectrodes, intracellularly injected with horseradish peroxidase, and prepared for electron microscopy. Post-embedding immunogold labelling with antibodies against gamma-aminobutyric acid (GABA) or glutamate was carried out either alone or together on the same section and allowed the identification of three classes of input synapses: 51% were immunoreactive for glutamate and contained round agranular vesicles, 31% were immunoreactive for GABA and contained pleomorphic agranular vesicles, and the remainder were immunoreactive for neither and also predominantly contained pleomorphic agranular vesicles. Output synapses were abundant in some of the motorneurones but were not seen in others, suggesting that members of the motor pool differ in their connectivity.
Watson
A H
AH
School of Biosciences, University of Wales Cardiff, Cardiff, CF10 3US, United Kingdom.
Bevengut
M
M
Pearlstein
E
E
Cattaert
D
D
D000818:Animals; D003400:Astacoidea / Q000737:chemistry* / Q000648:ultrastructure; D005260:Female; D018698:Glutamic Acid / Q000032:analysis*; D006614:Hindlimb / Q000737:chemistry / Q000294:innervation; D008297:Male; D009046:Motor Neurons / Q000737:chemistry* / Q000648:ultrastructure; D013569:Synapses / Q000737:chemistry* / Q000648:ultrastructure; D005680:gamma-Aminobutyric Acid / Q000032:analysis*
D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid