Structure of the pecten neuropil pathway and its innervation by bimodal peg afferents in two scorpion species
Fig 10
Innervation of the posterior pecten neuropil (PPN) of Heterometrus. petersii by distal (A-C) and proximal (D-F) peg afferents. Maximum projections of horizontal cLSM stacks. Synapsin-immunoreactivity (grey (not shown in B, C and E, F)) and anterograde tracing (green). (A) Tract from the pecten nerve enters the synganglion from posterior and proceeds laterally along the margin of the posterior pecten neuropil (PPN). PPN1 and 2 are innervated laterally. Furthermore, the entire anterior area of the anterior pecten neuropil (APN) is innervated by afferents. The innervation pattern reveals conspicuous glomerular-like structures (dotted outlines). (B) Higher magnification of APN from (A). Longitudinal tract splits into distinct branches (white arrowheads), each innervating a glomerular-like structure of APN. (C) Higher magnification of the PPN from (A). The labelled tract is thicker at the posterior end and finer at the anterior end. (D) Projection pattern of proximal peg afferents within the pecten neuropil. Longitudinal tract connects PPN and APN, the former being medially innervated by afferent fibres. (E) Higher magnification of APN from (D). The longitudinal axons terminate in two ellipsoid subcompartments in APN. (F) Higher magnification of the PPN from (D). The main projection area is located laterally and branches into the PPN1 and 2. Abbreviations: a: anterior; APN: anterior pecten neuropil; PPN1,2: posterior pecten neuropil 1, 2; p: posterior.