Electron Microscopy: the cephalic ganglion was immersed for six hours, at 4 [degrees]C, in a 0.
The cephalic ganglion of Onychophora showed a high level of neurobiological development.
In the cephalic ganglion of the Onychophora, the presence of subsynaptic cisterns formed by membranes of smooth endoplasmic reticulum was observed beneath the postsynaptic density.
In this study, our main interest was to demonstrate the high level of neurobiological development of the Onychophora, as shown by the presence of cephalic ganglion, well-differentiated neurons characterized by a high production of synaptic vesicles, and having a proportionality of their cytoplasm and nucleus very much similar to that of planarian neurons (Reuter 1981, Biserova et al.
sedgwicki cephalic ganglion is the presence of two principal types of synapses: excitatory and inhibitory, as shown in figures 4 and 5.