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Morphology and physiology of auditory interneurons in the metathoracic ganglion of the locust

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Summary

  1. 1.

    Auditory interneurons in the metathoracic ganglion of the locust were characterized by their intracellularly recorded responses to sound stimuli, and by their morphology as revealed in sectioned preparations of single neurons injected with Lucifer Yellow. Accordingly, nine interneurons were identified as either local, bisegmental, ascending or T-neurons (Figs. 2–6).

  2. 2.

    All cells possess arborizations within one or both sides of a prominent area of fine neuropil (frontal auditory neuropil), but the degree of overlap with the endings of tympanic afferents is different. For 2 ascending units (AN2, AN3) there is no overlap at all, indicating that they are interneurons of higher order.

  3. 3.

    Two neurons, SN1 and TN1, were found with only excitatory input to low frequency sound, and their tuning reflected that one of low frequency receptor fibres. In contrast, the response of all other neurons to low frequency stimuli was more complex, consisting of excitatory and inhibitory synaptic potentials. The neuronal circuitry which might underlie such physiological behaviour is discussed.

  4. 4.

    Recordings made from different parts of individual neurons enabled the sites of synaptic input and output to be localized. The postsynaptic dendrites of the interneurons appear to correspond to smooth endings in contrast to the beaded appearance of the presumptive presynaptic terminals (Fig. 8).

  5. 5.

    The results include descriptions of auditory ‘sister-neurons’ (Fig. 6) which have a similar morphology and of ‘twin-neurons’ (Fig. 7), which, using our present physiological and morphological criteria, cannot reliably be distinguished one from another. The problem that arises from such doubling of cells for the concept of identified units is discussed.

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References

  • Adam LJ (1969) Neurophysiologie des Hörens und Bioakustik einer Feldheuschrecke (Locusta migratoria). Z Vergl Physiol 63:227–289

    Google Scholar 

  • Altman JS, Kien J (1984) The anatomical basis for intersegmental and bilateral co-ordination in locusts. SEB Seminar Series (in press)

  • Boyan GS (1984) Neural mechanisms of auditory information processing by identified interneurons in Orthoptera. J Insect Physiol 30:27–41

    Google Scholar 

  • Čokl A, Kalmring K, Wittig H (1977) The response of auditory ventral-cord neurons ofLocusta migratoria to vibration stimuli. J Comp Physiol 120:161–172

    Google Scholar 

  • Dörrscheidt GJ, Rheinlaender J (1980) Computer generation of sound models for behavioural and neurophysiological experiments in insects. J Insect Physiol 26:717–727

    Google Scholar 

  • Eibl E, Huber F (1979) Central projections of tibial sensory fibres within the three thoracic ganglia of crickets (Gryllus campestris L.,Gryllus bimaculatus De Geer). Zoomorphologie 92:l-17

    Google Scholar 

  • Goodman CS (1974) Anatomy of locust ocellar interneurons: constancy and variability. J Comp Physiol 95:185–201

    Google Scholar 

  • Goodman CS (1976a) Constancy and uniqueness in a large population of small interneurons. Science 193:502–504

    Google Scholar 

  • Goodman CS, Pearson KG, Heitler WJ (1979) Variability of identified neurons in grasshoppers. Comp Biochem Physiol 64:455–462

    Google Scholar 

  • Kalmring K (1975) The afferent auditory pathway in the ventral cord ofLocusta migratoria (Acrididae). I. Synaptic connectivity and information processing among the auditory neurons in the ventral cord. J Comp Physiol 104:103–141

    Google Scholar 

  • Kalmring K, Rheinlaender J, Rehbein HG (1972a) Akustische Neuronen im Bauchmark der WanderheuschreckeLocusta migratoria. Z Vergl Physiol 76:314–332

    Google Scholar 

  • Kalmring K, Rheinlaender J, Römer H (1972b) Akustische Neuronen im Bauchmark vonLocusta migratoria. J Comp Physiol 80:325–352

    Google Scholar 

  • McIlwain JT, Creutzfeld OD (1967) Microelectrode study of synaptic excitation and inhibition in the lateral geniculate nucleus of the cat. J Neurophysiol 30:1–21

    Google Scholar 

  • Michelsen A (1971) The physiology of the locust ear. III. Acoustical properties of the intact ear. Z Vergl Physiol 71:102–128

    Google Scholar 

  • Moiseff A, Hoy R (1983) Sensitivity to ultrasound in an identified auditory interneuron in the cricket: a possible neuronal link to phonotactic behavior. J Comp Physiol 152:155–167

    Google Scholar 

  • Rehbein HG (1973) Experimentell-anatomische Untersuchungen über den Verlauf der Tympanalnervenfasern im Bauchmark von Feldheuschrecken, Laubheuschrecken und Grillen. Verh Dtsch Zool Ges 66:184–189

    Google Scholar 

  • Rehbein HG (1976) Auditory neurons in the ventral cord of the locust: morphological and functional properties. J Comp Physiol 110:233–250

    Google Scholar 

  • Rehbein HG, Kalmring K, Römer H (1974) Structure and function of acoustic neurons in the thoracic ventral cord ofLocusta migratoria. J Comp Physiol 95:263–280

    Google Scholar 

  • Rheinlaender J (1984) Das akustische Orientierungsverhalten von Heuschrecken, Grillen und Fröschen: Eine vergleichende neuro- und verhaltensphysiologische Untersuchung. Habilitationsschrift, Bochum

  • Rheinlaender J, Römer H (1980) Bilateral coding of sound direction in the CNS of the bushcricketTettigonia viridissima L. (Orthoptera, Tettigoniidae). J Comp Physiol 140:101–111

    Google Scholar 

  • Richardson KC, Jarett L, Finke EH (1960) Embedding in epoxy resins for ultrathin sectioning in electron microscopy. Stain Technol 35:313–323

    Google Scholar 

  • Robertson RM, Pearson KG (1983) Interneurons in the flight system of the locust: distribution, connections, and resetting properties. J Comp Neurol 215:33–50

    Google Scholar 

  • Römer H (1976) Die Informationsverarbeitung tympanaler Rezeptorelemente vonLocusta migratoria (Acrididae, Orthoptera). J Comp Physiol 109:102–122

    Google Scholar 

  • Römer H, Dronse R (1982) Synaptic mechanisms of monaural and binaural processing in the locust. J Insect Physiol 28:365–370

    Google Scholar 

  • Römer H, Rheinlaender J (1983) Electrical stimulation of the tympanal nerve as a tool for analysing the responses of auditory interneurons in the locust. J Comp Physiol 152:289–296

    Google Scholar 

  • Römer H, Rheinlaender J, Dronse R (1981) Intracellular studies on auditory processing in the metathoracic ganglion of the locust. J Comp Physiol 144:305–312

    Google Scholar 

  • Spurr AR (1969) A low-viscosity epoxy resin embedding medium for electron microscopy. J Ultrastruct Res 26:31–43

    Google Scholar 

  • Steeves JD, Pearson KD (1983) Variability in the structure of an identified interneuron in isogenic clones of locusts. J Exp Biol 103:47–54

    Google Scholar 

  • Stewart WW (1978) Functional connections between cells as revealed by dye-coupling with a highly fluorescent naphthalimide tracer. Cell 14:741–759

    Google Scholar 

  • Tyrer NM, Gregory GE (1982) A guide to the neuroanatomy of locust suboesophageal and thoracic ganglia. Phil Trans R Soc Lond 297:91–123

    Google Scholar 

  • Tyrer NM, Shaw MK, Altman JS (1980) Intensification of cobalt-filled neurons in sections (light and electron microscopy). In: Strausfeld NJ, Miller TA (eds) Neuroanatomical techniques, Springer, Berlin Heidelberg New York, pp 431–444

    Google Scholar 

  • Wohlers DW, Huber F (1978) Intracellular recording and staining of cricket auditory interneurons (Gryllus campestris L.,Gryllus bimaculatus De Geer). J Comp Physiol 127:11–28

    Google Scholar 

  • Wohlers DW, Huber F (1982) Processing of sound signals by six types of neurons in the prothoracic ganglion of the cricket,Gryllus campestris L. J Comp Physiol 146:161–173

    Google Scholar 

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Römer, H., Marquart, V. Morphology and physiology of auditory interneurons in the metathoracic ganglion of the locust. J. Comp. Physiol. 155, 249–262 (1984). https://doi.org/10.1007/BF00612642

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