Helically twisted filaments in giant neurons of a whip spider.

In giant neurons of whip spider legs several filament types are detectable: filaments of 5 to 6 nm thickness as dense masses within the soma of the neuron, an intermediate-sized filament type limited to the dendritic processes forming irregularly wound bundles and finally twisted double filaments in the soma as well as in peripheral regions. The latter are usually aggregated in paracristalloid lattices of different length and diameter.