Skip to main content


Fig. 2 | BMC Evolutionary Biology

Fig. 2

From: Serotonin-immunoreactivity in the ventral nerve cord of Pycnogonida – support for individually identifiable neurons as ancestral feature of the arthropod nervous system

Fig. 2

Architectural features of pycnogonid walking leg ganglia exemplified by Meridionale sp. a: Optical horizontal sections through walking leg ganglion 1, proceeding from ventral (uppermost) to farther dorsal; tubulin labeling (glow) with Hoechst counterstain (cyan). Note densely packed small nuclei of globuli-like cells (stippled ovals) in the anterior and posterior portions of the cortex. The large arrowhead marks a large cell soma in the midline region of the ganglion. Small arrowheads indicate different longitudinal neurite bundles passing through the neuropilar core. White arrows highlight chiasm-like transverse tracts, black arrow an antero-dorsal commissural tract. Note the slightly set off postero-ventral commissural tract (pvc). b: Transverse histological sections through walking leg ganglion 2, proceeding from anterior (uppermost) to farther posterior; midline region at the right side. Selected elongate and ovoid glomerulus-like neuropils are marked in the ventral ganglion half (stars and asterisks, respectively). Arrowheads indicate large cell somata in the midline region. Black arrows indicate commissural tracts

Back to article page