Abstract
Histological and electrophysiological studies of identified long hair sensilla (LHS) have provided information on primary afferent fibre pathways in the ventral nerve cord of the Indian black scorpion, Heterometrus fulvipes.
Cobalt-filling of single LHS on the metasoma showed that sensory axons enter the respective segmental ganglion, ascend ipsilaterally through the next anterior ganglia and terminate in a 4th ganglion. In each ganglion, these plurisegmental fibres give off collateral branches that terminate in the ganglionic neuropil. Fibres entering heterolateral connectives were not found.
Recordings from peripheral nerves after deflections of a hair showed single or multiple spike discharges. A single spike could be recorded from ipsilateral anterior connectives of the ventral nerve cord, indicating a through-conductance of the sensory pathways. Strong deflections of a single hair activated several ipsilateral and fewer contralateral ascending interneurons and some segmentai motor neurons. Behavioral studies demonstrate the mechanoreceptive function of the LHS.
The present study provides evidence in support of the notion that sensory afferents of the postabdomen in the scorpion bring about rapid, co-ordinated intersegmental movements of the multisegmented tail of the scorpion.
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Abbreviations
- CNS:
-
central nervous system
- LHS:
-
long hair sensillum
- TR:
-
trichobothria
References
Alexandrowicz JS (1951) Muscle receptor organs in the abdomen of Homarus vulgaris and Palinurus vulgaris. Q J Micr Sci 92:163–199
Altman JS, Tyrer NM (1974) Insect flight as a system for the study of the development of neuronal connections. In: Barton Browne L (ed) The experimental analysis of insect behavior. Springer, Berlin Heidelberg New York, pp 159–179
Anton S, Barth FG (1989) Central projections of spider trichobothria. In: Elsner N, Singer W (eds) Dynamics and plasticity in neuronal systems. Proc 17th Göttingen Neurobiol Conf, p 140
Anton S, Barth FG (1993) Central nervous projection patterns of trichobothria and other cuticular sensilla in the wandering spider Cupiennius salei (Arachnida, Araneae). Zoomorphology 113:21–32
Babu KS (1965) Anatomy of the central nervous system of arachnids. Zool Jb Anat 82:1–154
Babu KS, Barth FG (1989) Central nervous projections of a lyriform organ in the spider, Cupiennius salei Keys. Cell Tissue Res 258:69–82
Babu KS, Sanjeeva Reddy P (1967) Unit hair receptor activity from the telson of the scorpion Heterometrus fulvipes. Curr Sci 36:599–600
Babu KS, Kasaiah A, Jacobdoss P (1991) Cuticular receptors in the scorpion Heterometrus fulvipes. J Zool Soc India 42:1–16
Babu KS, Jacobdoss P, Rao RB, Sekhar V (1993) Central projections of primary fibres from a single hair sensillum in the scorpion Heterometrus fulvipes. Ind J Exp Biol 31:231–234
Bacon JP, Altman JS (1977) A silver intensification method for cobalt-filled neurons in wholemount preparations. Brain Res 138:359–363
Bacon JP, Tyrer M (1979) The innervation of the wind sensitive head hairs of the locust Schistocerca gregaria. Physiol Entomol 4:301–309
Barth FG (1985) Neuroethology of the spider vibration sense. In: Barth FG (ed) Neurobiology of arachnids. Springer, Berlin Heidelberg New York Tokyo, pp 203–229
Bräunig P, Hustert R (1980) Proprioceptors with central cell bodies in insects. Nature 283:768–770
Bräunig P, Hustert R, Pflüger HJ (1981) Distribution and specific central projections of mechanoreceptors in the thorax and proximal leg joints of locusts. 1. Morphology, location and innervation of internal proprioceptors of pro- and metathorax and their central projections. Cell Tissue Res 216:57–77
Brownell P, Farley RD (1979a) Detection of vibrations in sand by tarsal sense organs of the nocturnal scorpion Paruroctonus mesaensis. J Comp Physiol 131:23–30
Brownell P, Farley RD (1979b) Orientations to vibrations in sand by the nocturnal scorpion Paruroctonus mesaensis: mechanism of target localization. J Comp Physiol 131:31–38
Eckweiler W, Seyfarth EA (1988) Tactile hairs and the adjustment of body height in wandering spiders: behavior, leg reflexes, and afferent projections in the leg ganglia. J Comp Physiol A 162:611–621
Fields HL, Kennedy D (1965) Functional role of muscle receptor organs in crayfish. Nature 206:1232–1237
Foelix RF, Schabronath J (1983) The fine structure of scorpion sensory organs. I. Tarsal sensilla. Bull Br Arachnol Soc 6:53–67
Hanström B (1921) Über die Histologie und vergleichende Anatomie der Sehganglien und Globuli der Araneen. Kgl Svenska Vet Akad Handl 61:1–39
Hanström B (1928) Vergleichende Anatomie des Nervensystems der wirbellosen Tiere. Springer, Berlin
Hoffmann C (1967) Bau und Funktion der Trichobothrien von Euscorpius carpathicus L. Z Vergl Physiol 51:290–352
Ignat'yev AM, Ivanov VP, Balashov YS (1976) The fine structure and function of the trichobothria in the scorpion Buthus eupeus Koch (Scorpiones, Buthidae). Entomol Rev 55:12–18
Jacobdoss P (1990) Cuticular receptors in the scorpion Heterometrus fulvipes: Distribution, structure and post-natal development. M. Phil Dissertation. Sri Venkateswara University, Tirupati, Andhra Pradesh, India
Jacobdoss P (1993) Long hair sensilla in the scorpion, Heterometrus fulvipes: Central projections, physiology and behavior. Doctoral Dissertation, Sri Venkateswara University, Tirupati, Andhra Pradesh, India
Kasaiah A (1989) Neuroethology of the scorpion, Heterometrus fulvipes: Habitat, cuticular receptors and behavior. Doctoral Dissertation, Sri Venkateswara University, Tirupati, Andhra Pradesh, India
Kasaiah A, Sekhar V, Rajarami Reddy G, Sasira Babu K (1989) Distribution and innervation of cuticular sense organs in the scorpion, Heterometrus fulvipes. In: Singh RN, Strausfeld NJ (eds) Neurobiology of sensory systems. Plenum Press, New York, pp 581–591
Levine RB, Pak C, Linn D (1985) The structure, function and metamorphic reorganization of somatically projecting sensory neurons in Manduca sexta larvae. J Comp Physiol A 157:1–13
Linsenmair KE (1968) Anemotaktische Orientierung bei Skorpionen (Chelicerata, Scorpiones). Z Vergl Physiol 60:445–449
Padmanabha Naidu B (1967) A new perfusion fluid for the scorpion, Heterometrus fulvipes. Nature 213:410
Palka J, Babu KS (1967) Towards the physiological analysis of defensive responses of scorpions. Z Vergl Physiol 55:286–298
Pflüger HJ (1980) Central nervous projections of sternal trichoid sensilla in locusts. Naturwissenschaften 67:316
Pflüger HJ, Bräunig P, Hustert R (1988) The organization of mechanosensory neuropiles in locust thoracic ganglia. Phil Trans R Soc Lond B 321:1–26
Rao RB (1992) Neural organization in ventral nerve cord of the scorpion, Heterometrus fulvipes. M Phil Dissertation Sri Venkateswara University, Tirupati, Andhra Pradesh, India
Reissland A, Görner P (1985) Trichobothria. In: Barth FG (ed) Neurobiology of arachnids. Springer, Berlin Heidelberg New York Tokyo, pp 138–161
Root TM (1990) Neurobiology. In: Polis GA (ed) The biology of scorpions. Stanford Univ Press, Stanford, pp 341–413
Sanjeeva Reddy P (1969) Studies on the input from a hair sensillum into the central nervous system of the scorpion, Heterometrus fulvipes. Doctoral Dissertation, Sri Venkateswara University, Tirupati, Andhra Pradesh, India
Sanjeeva Reddy P (1971) Function of the supernumerary sense cells and the relationship between modality of adequate stimulus and innervation pattern of the scorpion hair sensillum. J Exp Biol 54:233–238
Tyrer NM, Altman JS (1974) Motor and sensory flight neurons in a locust demonstrated using cobalt chloride. J Comp Neurol 157:117–139
Tyrer NM, Bacon JP, Davies CA (1979) Sensory projections from the wind-sensitive head hairs of the locust Schistocerca gregaria. Cell Tissue Res 203:79–92
Venkateswara Rao P (1963) Studies on the peripheral nervous system of the scorpion, Heterometrus fulvipes. Doctoral Dissertation, Sri Venkateswara University, Tirupati, Andhra Pradesh, India
Wiersma CAG, Hughes GM (1961) On the functional anatomy of neuronal units in the abdominal cord of the crayfish, Procambarus clarkii (Girard). J Comp Physiol 116:209–228
Yellamma K, Subhashini K, Murali Mohan P, Sasira Babu K (1983) Synaptic transmission in the 7th abdominal ganglion of the scorpion, Heterometrus fulvipes. Ind J Physiol Pharmacol 27:13–18
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Babu, K.S., Jacobdoss, P. Central afferent pathways of long hair sensilla in the ventral nerve cord of the Indian black scorpion, Heterometrus fulvipes Koch. J Comp Physiol A 174, 495–505 (1994). https://doi.org/10.1007/BF00191715
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DOI: https://doi.org/10.1007/BF00191715