TY - JOUR T1 - Development of the auditory tympana in the cricket Teleogryllus commodus (Walker): Experiments on regeneration and transplantation JF - Experientia Y1 - 1979 A1 - Eldon E. Ball AB -

Grafting and regeneration experiments on prothoracic legs of the cricketTeleogryllus commodus (Walker) demonstrate: a) that the legs retain their identity, as indicated by formation of tympanal cuticle in the adult, when transplanted to the site of a mesothoracic leg in immature animals, and b) that the presence of tympanal cuticle on a regenerate leg depends on the instar of amputation.

VL - 35 UR - http://link.springer.com/10.1007/BF01964328 IS - 3 JO - Experientia ER - TY - JOUR T1 - Functional development of the auditory system of the cricket,Teleogryllus commodus JF - Journal of Comparative Physiology ? A Y1 - 1978 A1 - Eldon E. Ball A1 - Hill, K. G. AB -

1. In Teleogryllus commodus and T . oceanicus, vibration of the tibia of the prothoracic leg at audio-frequencies stimulates auditory receptors in the tympanal organ, despite immobilization of the large tympanum by vaseline.

2.Responses of characteristic auditory interneurons in the adult cervical connective are similar whether stimulation is by sound or by vibration of the tibia (Figs. 3–5).

3.Interneurons in second-last (A-2) and last (A-1) immature instars are stimulated by sound and by vibration of the tibia and we conclude that these interneurons are the same as those recorded in adults (Figs. 6, 7). Peripheral receptors and some interneurons in the immature auditory system are, therefore, physiologically competent.

4.At the imaginai moult, auditory threshold at the optimum frequency decreases dramatically (Fig. 8 A). This increase in sensitivity to sound is attributed mainly to the appearance of the auditory tympanum in the adult. There is a much smaller increase in sensitivity to vibration of the tibia at audio frequencies between last instar nymphs and adults (Fig. 8 B).

5.From the A-2 to adult stages of T. commodus, auditory receptors stimulated by sound show a peak sensitivity at 3.8 to 4.0 kHz (Fig. 8 A). Such tuning must be independent of vibration characteristics of the tympanum and of acoustic resonance characteristics depending on the dimensions of the leg trachea.

VL - 127 UR - http://link.springer.com/10.1007/BF01352297 IS - 2 JO - J. Comp. Physiol. ER - TY - JOUR T1 - Structure and development of the auditory system in the prothoracic leg of the cricket Teleogryllus commodus (Walker) II. Postembryonic development JF - Zeitschrift für Zellforschung und mikroskopische Anatomie Y1 - 1974 A1 - Eldon E. Ball A1 - Young, David AB -

The anatomical development of the tympanal organ, the tracheal system and the tympana of Teleogryllus commodus is described. The tympanal organ is undifferentiated until instar 3 when the first scolopales appear. The organ develops in a proximo-distal direction but the more distal groups begin to form before the proximal groups are complete. All groups of scolopidia are represented in instar 7 but numbers of scolopidia continue to increase until the adult stage. Scolopales and scolopale cells are first formed at less than adult size and increase in size during subsequent instars. The subgenual organ is present in instar 1 and is complete in instar 4. The posterior and anterior tympanal trachease develop respectively from the tracheal trunk and tracheal branch, which are present from instar 2. These remain as simple, unconnected tubes until instar 7 and begin to show the adult form during instars 8 and 9, finally enlarging in conjunction with the tympana at the last two moults. The tympana first appear as hairless areas of cuticle in the larval stages: the posterior tympanum in instar 8 and anterior tympanum in instar 10, but the translucent appearance of the adult tympana is not present before the final moult.

VL - 147 UR - http://link.springer.com/10.1007/BF00307467 IS - 3 JO - Z.Zellforsch ER - TY - JOUR T1 - Structure and development of the auditory system in the prothoracic leg of the cricket Teleogryllus commodus (Walker) I. Adult structure JF - Zeitschrift für Zellforschung und mikroskopische Anatomie Y1 - 1974 A1 - Young, David A1 - Eldon E. Ball AB -

The microanatomy of the adult auditory system of the cricket, Teleogryllus commodus, is described with special attention to the number and arrangement of the groups of scolopidia forming the tympanal organ.

In the proximal part of the prothoracic tibia, there is a large posterior tympanum and a smaller anterior tympanum, which are associated internally with two expanded chambers of the tracheal system. The tympanal organ, which is identical in both sexes, is situated on the dorsal surface of the anterior tympanal trachea. It contains about 70 scolopidia, divided into two main groups: the proximal group, whose attachment cells insert on large accessory cells dorsally within the tympanal organ, and the distal group, whose attachment cells insert on modified dorsal hypodermal cells. These groups can be further divided into five main types, each containing a relatively constant number of scolopidia: 1. proximal group A; 2. proximal main group with proximal neurons; 3. proximal main group with distal neurons; 4. proximal part of distal group; 5. distal part of distal group. These types differ consistently in the following features: location of sensory neuron, orientation of dendrite and scolopale cell, structure of scolopale cell, shape and orientation of attachment cell and its connection to the secondary attachment cell.

VL - 147 UR - http://link.springer.com/10.1007/BF00307466 IS - 3 JO - Z.Zellforsch ER - TY - JOUR T1 - Structure of the auditory system of the weta Hemideina crassidens (Blanchard, 1851). (Orthoptera, Ensifera, Gryllacridoidea, Stenopelmatidae). 2. Ultrastructure of the auditory sensilla. JF - Cell Tissue Res Y1 - 1981 A1 - Eldon E. Ball KW - Animals KW - Auditory Pathways KW - electron microscopy KW - female KW - hearing KW - male KW - mechanoreceptors KW - Orthoptera AB -

This study of the ultrastructure of the auditory sensilla of the New Zealand weta, Hemideina crassidens, is the first such study on a member of the orthopteran Superfamily Gryllacridoidea. Ultrastructure of the auditory sensilla is similar in all of the tibial mechanosensory organs, here called subgenual organ, intermediate organ and crista acoustica by analogy with comparable structures in Tettigoniidae. Distal to each sensory soma is a dendrite containing multiple ciliary rootlets that fuse into a single ciliary root. This splits into nine root processes that pass around the outside of the proximal basal body and then rejoin at the level of the distal basal body, distal to which the dendrite has a modified ciliary structure with a circlet of nine peripheral paired tubes and rods as it passes through the proximal extracellular space. It is then enclosed by a zone of scolopale cell cytoplasm before expanding into a dilatation within the distal extracellular space. In some sensilla this space is partially occluded by electron dense material which is part of the scolopale cell. Distal to the dilatation the cilium shrinks and ends surrounded by the scolopale cap. Accessory cells consist of glia enwrapping the sensory neuron in the region of its soma, the scolopale cell surrouinding the ciliary portion of the dendrite, and the attachment cell surrounding the scolopale cell and scolopale cap and connected to them by desmosomes. The attachment cells are filled with microtubules in differing densities and orientations. Lamellae are present in the acellular matrix surrounding the attachment cells. Banded fibres, presumably of collagen, are also present in the matrix.

VL - 217 IS - 2 ER - TY - JOUR T1 - Structure of the auditory system of the weta Hemideina crassidens (blanchard, 1851) (Orthoptera, Ensifera, Gryllacridoidea, Stenopelmatidae). 1. Morphology and histology. JF - Cell Tissue Res Y1 - 1981 A1 - Eldon E. Ball A1 - Field, L H KW - Animals KW - female KW - hearing KW - male KW - Orthoptera KW - species specificity KW - vestibulocochlear nerve AB -

The morphology and histology of the tibial auditory system of the New Zealand weta, Hemideina crassidens, are described. The groups of acoustic sensilla conform closely to the subgenual organ, intermediate organ and crista acoustica of the Tettigoniidae. Each prothoracic tibia bears two thick (40-100 micrometers) tympana of approximately equal size divided into two distinct zones. The tracheae of the prothoracic legs are connected across the midline by a transverse commissure and by a chiasma between the ventral longitudinal trunks. No expanded vesicle ("vesicula acoustica") is associated with the spiracle. The anterior and posterior tracheae are divided into three distinct regions within the tibia: (1) a bulbous proximal posterior inflated chamber, (2) the tympanal vesicles to which the tympana attach, and (3) an elongate distal posterior inflated chamber. The pattern of innervation in the tympanal region is similar to that of gryllids as is the central projection of the tympanal nerve. The subgenual organ, which contains ca. 50 sensilla, forms an acute angle with the wall of the leg. The intermediate organ contains ca. 19 sensilla forming an arc against the anterior wall of the leg. The crista acoustica contains ca. 50 sensilla aligned in a gelatinous matrix along the dorsal surface of the anterior tympanal vesicle. Each dendrite projects distally, then is reflected proximally and dorsally to end in a scolopale embedded in an attachment cell. The attachment cells are stellate in the proximal portion of the crista, but distally they occur as parallel lamellae. The weta ear is compared with those of other Orthoptera.

VL - 217 IS - 2 ER - TY - JOUR T1 - Ultrastructural study of the development of the auditory tympana in the cricket Teleogryllus commodus (Walker). JF - J Embryol Exp Morphol Y1 - 1978 A1 - Eldon E. Ball A1 - Cowan, A N KW - Animals KW - epidermis KW - microvilli KW - middle ear KW - Orthoptera AB -

The cuticle in the tympanal area of immature crickets, Teleogryllus commodus (Walker), is ultrastructurally indistinguishable from that elsewhere on the prothoracic leg. It is only in the pharate adult that changes associated with development of the tympana first appear. In pharate adults and adults the external layer of the tympana consists of a layer of electron-dense material overlying a layer where the electron-dense material is interspersed with cuticle in which the bundles of microfibrils are coarser and more loosely arranged than elsewhere in the leg. The innermost portion of the tympana consists of this same type of cuticle without the electron-dense material. Associated with the appearance of the electron-dense material in the tympana of the pharate adult is a change in the toluidine blue staining properties from blue to deep purple. The reaction of the tympana in acid and base is consistent with their being composed of chitin. There are no major deposits of resilin in the tympana. In the first few days following the imaginal ecdysis the posterior tympanum and underlying trachea come into tight apposition due to the withdrawal of the epidermal cells. The epidermal cells do not withdraw from beneath the anterior tympanum. The surrounding non-tympanal cuticle continues to thicken for several weeks with the result that in the mature adult the posterior tympanum serves as an acoustic window in the thick cuticle of the leg. The functional significance of the anterior tympanum has not been established.

VL - 46 ER -