Structure of the pecten neuropil pathway and its innervation by bimodal peg afferents in two scorpion species
Fig 7
Innervation of the pecten neuropils by sensory axons in Mesobuthus eupeus and Heterometrus petersii.
Maximum projections of horizontal cLSM stacks. Tubulin-immunoreactivity (blue) and anterograde tracing of afferents (green). (A) The entire pecten neuropil exhibits innervation by pecten afferents. Afferent bundles (AB) of the pecten nerve project into the posterior pectines neuropil 1 (PPN1) (white outlined arrow). Adjacent accessory pecten neuropils 1 and 2 (AN1,2) (white arrows), the ascending (AT) and the longitudinal tract (LtT) (white arrowhead) exhibit Neurobiotin labelling. (B) Ventral section of anterior pecten neuropil (APN) and adjacent neuropils. Anterior to PPN3, the ascending tract (arrowhead) proceeds parallel to the APN and innervates the AN1. (C) The longitudinal tract connects the AN1 and AN2 (white arrowhead) dorsally. (D) Anterograde tracing of the entire pecten nerve results in labelling in PPN, APN and AN of Heterometrus petersii. Ascending tract emerges anterior to the walking leg neuromere 4 (WLN4) and innervates the accessory neuropil. Proceeding tract leaves the AN anteriorly. Abbreviations: a: anterior; AB: afferent bundles; AN1,2: accessory neuropil 1, 2; APN: anterior pecten neuropil; AT: ascending tract; LtT: longitudinal tract; p: posterior, PPN1-3: posterior pecten neuropil 1–3; PT: proceeding tract; WLN3-4: walking leg neuromere 3–4.