Journal of Comparative Physiology A

, Volume 205, Issue 2, pp 253–270 | Cite as

Identification of the origin of force-feedback signals influencing motor neurons of the thoraco-coxal joint in an insect

  • Anna Haberkorn
  • Matthias Gruhn
  • Sasha N. Zill
  • Ansgar BüschgesEmail author
Original Paper


Force feedback from Campaniform sensilla (CS) on insect limbs helps to adapt motor outputs to environmental conditions, but we are only beginning to reveal the neural control mechanisms that mediate these influences. We studied CS groups that affect control of the thoraco-coxal joint in the stick insect Carausius morosus by applying horizontal and vertical forces to the leg stump. Motor effects of ablation of CS groups were evaluated by recording extracellularly from protractor (ProCx) and retractor (RetCx) nerves. Extracellular recordings showed that the effects of stimulating the sensilla were consistent with their broad ranges of directional sensitivity: for example, RetCx firing in response to posterior bending could be reduced by ablating several groups of trochanteral CS, whereas ablation of tibial and femoral sensilla had little effect. In contrast, ProCx motor neuron activity upon anteriorly directed stimuli was affected mainly by ablating a single CS group (G2). Dye fills of trochanteral, femoral and tibial CS groups with fluorescent dyes revealed a common projection pattern with little group specificity. These findings support the idea that the influences of CS feedback are determined by the activities of pre-motor interneurons, facilitating fast and task-dependent adaptation to changing environmental conditions.


Mechanosensation Motor control Locomotion Load feedback Campaniform sensilla 




C. morosus

Carausius morosus


Campaniform sensilla






Nervus cruris




Protractor coxae


Retractor coxae



We sincerely thank H.-P. Bollhagen for excellent technical assistance at the scanning electron microscope, S. Seyed-Nejadi, S. Seeliger, and M. Dübbert for providing laboratory and technical support, and Ch. Mantziaris for helpful advice and inspiring discussions. We also thank the Imaging Facility of the Cologne Biocenter for support of our study. Finally, we thank the two anonymous reviewers for their constructive criticism that helped us to improve the manuscript. We confirm that all animals were kept and handled according to the pertinent guidelines. This study was supported by DFG Bu 857/14.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

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Supplementary material 1 (DOCX 26 KB)
359_2019_1334_MOESM2_ESM.tif (64.6 mb)
Supplementary material 2 (TIFF 66195 KB)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Anna Haberkorn
    • 1
  • Matthias Gruhn
    • 1
  • Sasha N. Zill
    • 1
    • 2
  • Ansgar Büschges
    • 1
    Email author
  1. 1.Department for Animal Physiology, Institute for Zoology, Biocenter CologneUniversity of CologneCologneGermany
  2. 2.Department of Biomedical Sciences, Joan C. Edwards School of MedicineMarshall UniversityHuntingtonUSA

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