[Ultrastructural organization of the gastric ganglion in the crayfish]

Anatomy of the gastric ganglion in the stomatogastric region of the vegetative nerve system has been studied in Astacus astacus at light optic and ultrastructural levels. Topography, neuroglial and interneuronal relationships of its elements have been described. Various types of synapses of the ganglionic neuropil have been described. The role of the ganglionic structural elements in receiving and treating sensory information and in regulation of gastric movements is discussed.