Structure of the pecten neuropil pathway and its innervation by bimodal peg afferents in two scorpion species
Wissenschaftlicher Artikel
Authors
Drozd, Denise
Wolf, Harald
Stemme, Torben
Faculties
Fakultät für NaturwissenschaftenInstitutions
Institut für NeurobiologiePublished in
PLoS ONE ; 15 (2020), 12. - Art.-Nr. e0243753. - eISSN 1932-6203
Link to original publication
https://dx.doi.org/10.1371/journal.pone.0243753Peer review
ja
Document version
publishedVersion
Abstract
The pectines of scorpions are comb-like structures, located ventrally behind the fourth walking
legs and consisting of variable numbers of teeth, or pegs, which contain thousands of
bimodal peg sensillae. The associated neuropils are situated ventrally in the synganglion,
extending between the second and fourth walking leg neuromeres. While the general morphology
is consistent among scorpions, taxon-specific differences in pecten and neuropil
structure remain elusive but are crucial for a better understanding of chemosensory processing.
We analysed two scorpion species (Mesobuthus eupeus and Heterometrus petersii)
regarding their pecten neuropil anatomy and the respective peg afferent innervation with
anterograde and lipophilic tracing experiments, combined with immunohistochemistry and
confocal laser-scanning microscopy. The pecten neuropils consisted of three subcompartments:
a posterior pecten neuropil, an anterior pecten neuropil and a hitherto unknown
accessory pecten neuropil. These subregions exhibited taxon-specific variations with regard
to compartmentalisation and structure. Most notable were structural differences in the anterior
pecten neuropils that ranged from ovoid shape and strong fragmentation in Heterometrus
petersii to elongated shape with little compartmentalisation in Mesobuthus eupeus.
Labelling the afferents of distinct pegs revealed a topographic organisation of the bimodal
projections along a medio-lateral axis. At the same time, all subregions along the posterioranterior
axis were innervated by a single peg’s afferents. The somatotopic projection pattern
of bimodal sensillae appears to be common among arachnids, including scorpions. This
includes the structure and organisation of the respective neuropils and the somatotopic projection
patterns of chemosensory afferents. Nonetheless, the scorpion pecten pathway exhibits unique features, e.g. glomerular compartmentalisation superimposed on somatotopy,
that are assumed to allow high resolution of substrate-borne chemical gradients.
Funding information
DFG [STE2826-1-1]
Subject Headings
Neuropil [GND]Skorpione [GND]
Axon [GND]
Neuropilins [LCSH]
Scorpions [LCSH]
Walking [LCSH]
Axons [LCSH]
Central nervous system [LCSH]
Sensory neurons [LCSH]
Keywords
Sensory perception; Nerve fibers; Ganglia; Somatosensory system; SPIDER CUPIENNIUS-SALEI; ELAPHUS POCOCK ARACHNIDA; CENTRAL PROJECTIONS; OLFACTORY SYSTEMS; FORELEGS WHIPS; ANTENNAL LOBE; MECHANOSENSORY NEURONS; CONTACT CHEMORECEPTIONDewey Decimal Group
DDC 570 / Life sciencesDDC 590 / Animals (Zoology)
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Drozd, Denise; Wolf, Harald; Stemme, Torben (2021): Structure of the pecten neuropil pathway and its innervation by bimodal peg afferents in two scorpion species. Open Access Repositorium der Universität Ulm. http://dx.doi.org/10.18725/OPARU-34362