Abstract
Our previous studies on spider tactile hairs concentrated on the mechanical behavior of the hair shaft and the electrophysiological properties of the sensory cells. Here we focus on the structure and mechanical properties of the coupling of the hair shaft and the sensory terminals. 1. The functional “design” of the coupling provides for a combination of high sensitivity and protection against mechanical damage and overstimulation. The dendritic sheath is not directly coupled to the hair shaft. Rather, there is “terminal connecting material” between the dendrites and the hair shaft. 2. The hair shaft forms a first-order lever. Its acentric axis of rotation is located ca.3.5 μm from its inner end. Displacement of the hair tip is scaled down by a factor of ca.750:1, not even considering the outer hair shaft’s bending. 3. At threshold the dendrite sheath displacement is ca. 0.05 μm by forces in the order of 0.4–4×10−6 N. 4. The hair shaft bends within the socket even before contacting it. The elasticities representing its suspension and bending in the socket can be described quantitatively by measuring the hair’s restoring moments (range: 10−9 Nm) and bending at different degrees of deflection.
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References
Albert JT, Friedrich OC, Dechant H-E, Barth FG (2001) Arthropod touch reception: spider hair sensilla as rapid touch detectors. J Comp Physiol A 187:303–312
Barth FG (2000) How to catch the wind: spider hairs specialized for sensing the movement of air. Naturwissenschaften 87:51–58
Barth FG (2002a) Spider senses—technical perfection and biology. Karl von Frisch-Lecture. Zoology 105:271–285
Barth FG (2002b) A spider’s world: senses and behavior. Springer, Berlin Heidelberg New York
Barth FG, Dechant H-E (2003) Arthropod cuticular hairs: tactile sensors and the refinement of stimulus transformation. In: Barth FG, Humphrey JAC, Secomb TW (eds) Sensors and sensing in biology and engineering. Springer, Berlin Heidelberg New York, pp 159–171
Dechant H-E (2001) Mechanical properties and finite element simulation of spider tactile hairs. Thesis, University of Vienna
Dechant H-E, Rammerstorfer FG, Barth FG (2001) Arthropod touch reception: stimulus transformation and finite element model of spider tactile hairs. J Comp Physiol A 187:313–322; see also Erratum p 851
Foelix RF (1970) Structure and function of tarsal sensilla in the spider Araneus diadematus. J Exp Zool 175:99–124
Foelix RF (1985) Mechano- and chemoreceptive sensilla. In: Barth FG (ed) Neurobiology of arachnids. Spinger, Berlin Heidelberg New York, pp 118–138
Foelix RF (1992) Biologie der Spinnen. Thieme, Stuttgart
Foelix RF, Chu-Wang I-W (1973) The morphology of spider sensilla. I. Mechanoreceptors. Tissue Cell 5:451–460
Friedrich OC (2001) Zum Berührungssinn von Spinnen. Thesis, University of Vienna
Gaffal KP, Tichy H, Theiß J, Seelinger G (1975) Structural polarities in mechanosensitive sensilla and their influence on stimulus transmission (Arthropoda). Zoomorphology 82:79–103
Gnatzy W, Tautz J (1980) Ultrastructure and mechanical properties of an insect mechanoreceptor: stimulus-transmitting structures and sensory apparatus of the cercal filiform hairs of Gryllus. Cell Tissue Res 213:441–463
Harris DJ, Mill PJ (1977) Observations on the leg receptors of Ciniflo (Araneidae: Dictynidae). I. External mechanoreceptors. J Comp Physiol 119:37–54
Humphrey JAC, Barth FG, Reed M, Spak A (2003) The physics of arthropod medium-flow sensitive hairs: biological models for artificial sensors. In: Barth FG, Humphrey JAC, Secomb TW (eds) Sensors and sensing in biology and engineering. Springer, Berlin Heidelberg New York, pp 129–144
Keil TA (1997) Functional morphology of insect mechanoreceptors. Microsc Res Tech 39:506–531
Maier L, Root TM, Seyfarth E-A (1987) Heterogeneity of spider leg muscle: histochemistry and electrophysiology of identified fibres in the claw levator. J Comp Physiol B 157:285–294
Shimozawa T, Murakami J, Kumagai T (2003) Cricket wind receptors: thermal noise for the highest sensitivity known. In: Barth FG, Humphrey JAC, Secomb TW (eds) Sensors and sensing in biology and engineering. Springer, Berlin Heidelberg New York, pp 145–157
Theiß J (1979) Mechanoreceptive bristles on the head of the blowfly: mechanics and electrophysiology of the macrochaetae. J Comp Physiol 132:55–68
Thurm U (1982) Mechano-elektrische Transduktion. In: Hoppe W, Lohmann W, Markl H, Ziegler H (eds) Biophysik. Springer, Berlin Heidelberg New York, pp 390–396
Ullrich N (2000) Feinstruktur und zentrale Projektion von Tasthaaren bei Cupiennius salei Keys. (Ctenidae). Diploma thesis, University of Vienna
Wiese K (1976) Mechanoreceptors for near-field water displacement in crayfish. J Neurophysiol 39:816–833
Acknowledgements
Supported by a grant of the Austrian Science Foundation (FWF, P12192-BIO) to F.G.B. We are very grateful to Margit Kainerstorfer for help with the preparation of the figures.
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Barth, F.G., Németh, S.S. & Friedrich, O.C. Arthropod touch reception: structure and mechanics of the basal part of a spider tactile hair. J Comp Physiol A 190, 523–530 (2004). https://doi.org/10.1007/s00359-004-0497-4
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DOI: https://doi.org/10.1007/s00359-004-0497-4