Effect of picrotoxin on the tympanic organ of a noctuoid moth

1986 ◽  
Vol 73 (8) ◽  
pp. 501-502 ◽  
Author(s):  
M. P�rez ◽  
F. Coro
Keyword(s):  
Tympanic Organ

Central Mechanism of Hearing in Insects

1961 ◽  
Vol 38 (3) ◽  
pp. 545-558 ◽  
Author(s):  
NOBUO SUGA ◽  
YASUJI KATSUKI
Keyword(s):  
Sound Source ◽  
Threshold Curve ◽  
Inhibitory Interaction ◽  
Response Range ◽  
Metathoracic Ganglion ◽  
Hair Sensilla ◽  
Prothoracic Ganglion ◽  
Tympanic Organ ◽  
Large Fibre ◽  
The Brain

1. The impulses from the tympanic organ are transmitted at the prothoracic ganglion to a central neuron, the auditory T large fibre, which lies in the cord between the brain and the metathoracic ganglion. The impulses in the T large fibre are conducted rostrally and caudally with the same discharge pattern. Information is sent up to the brain, and down to the metathoracic ganglion, after a delay of about 12 msec. 2. The impulses from the cercal hair sensilla are transmitted to two similar auditory C large fibres which lie in the cord between the metathoracic and last (6th) abdominal ganglia and are then sent up to the mesothoracic ganglia by other auditory large fibres. 3. Central inhibitory interaction between the impulses from the tympanic nerves of the two sides are shown by a marked increase of impulses in the T large fibre following section of one of the tympanic nerves. No inhibitory interaction is found between the impulses from the two cercal nerves. 4. The auditory T large fibre receives not only the excitatory effect from the ipsilateral tympanic nerve at the prothoracic ganglion, but also the inhibitory and weak excitatory effects from the contralateral one. 5. The response range of the T large fibre is narrower than the threshold curve of the tympanic nerve and corresponds with one type of response range in the tympanic neurons. The response ranges of the C large fibres correspond closely with the threshold curve of the cercal nerve. 6. A large difference in threshold between the two T large fibres is found in the response to sound incident from the side. The number of impulses in the T large fibre nearer to the sound source is greater than in that farther from the source. 7. The difference in the number of impulses between the two T large fibres is most marked in the response to sound of the frequency which is dominant in stridulation. This difference is due to the mutual inhibitory interaction of neurons which modifies the number of impulses without changing the threshold of the tympanic large fibre. 8. It is suggested that the central inhibitory interaction increases the information about a sound source and plays an important role in the mechanism of the directional sense. 9. The stridulation of the group activates the tympanic nerve and evokes synchronized discharge in the T large fibre, but scarcely at all in the primary C large fibre. The tympanic organ and its neural network seem well adapted to reception of stridulation. 10. It is concluded that though neither of the two sound receptive organs--the tympanic organ and the cercal hair sensilla--can perform frequency analysis, the insect may be able to do so by making use of both organs, since they have different frequency ranges and are served by different auditory large-fibre tracts.

Ultrasonic reception by the tympanic organ of noctuid moths

1957 ◽  
Vol 134 (1) ◽  
pp. 127-157 ◽  
Author(s):  
Kenneth D. Roeder ◽  
Asher E. Treat
Keyword(s):  
Tympanic Organ

Peripheral interaction in the tympanic organ of a moth

1983 ◽  
Vol 70 (2) ◽  
pp. 99-100 ◽  
Author(s):  
F. Coro ◽  
M. P�rez
Keyword(s):  
Peripheral Interaction ◽  
Tympanic Organ

Acoustic responsiveness of Scoliopteryx libatrix L. (Lepidoptera: Noctuidae), a moth that shares hibernacula with some insectivorous bats

1973 ◽  
Vol 51 (7) ◽  
pp. 681-685 ◽  
Author(s):  
K. D. Roeder ◽  
M. B. Fenton
Keyword(s):  
Avoidance Response ◽  
Behavioral Response ◽  
Room Temperature ◽  
Insectivorous Bats ◽  
Auditory Detection ◽  
Tympanic Organ ◽  
Lepidoptera Noctuidae

Adult Scoliopteryx libatrix L. overwinter in the entrance areas of caves and mines in Ontario, which also harbor hibernating bats. The tympanic organs of S. libatrix taken from hibernation and tested at room temperature were found to be sensitive to ultrasound between 20 and 40 kHz, which overlaps with the frequencies used by the bats with which it shares hibernacula. The sensitivity of the tympanic organ and the connector neurons in the protocerebrum is +5–10 decibels (dB) greater than those of other noctuid moths for which data are available. In spite of the auditory detection of ultrasonic pulses and transmission of the resultant stimuli to the protocerebrum, S. libatrix in stationary flight showed no avoidance response to a source of ultrasonic pulses. This behavior is markedly different from that of some other noctuid moths tested during their activity periods. The significance of the absence of a behavioral response in the moths is discussed in relation to the activity of bats around the caves and mines.

Pitch discrimination in locusts

1961 ◽  
Vol 155 (959) ◽  
pp. 218-231 ◽  
Keyword(s):  
Schistocerca Gregaria ◽  
Locusta Migratoria ◽  
Pitch Discrimination ◽  
High Pitch ◽  
Sound Stimulation ◽  
Sensory Axons ◽  
Metathoracic Ganglion ◽  
Tympanic Organ ◽  
The Brain ◽  
Stimulation Of

Sound stimulation of the tympanic organ of Locusta migratoria and Schistocerca gregaria initiates responses in the tympanic nerve and these in turn stimulate a few interneurones which ascend the ventral cord from the metathoracic ganglion to the brain. Some of the preparations show the following evidence of pitch discrimination. The response of the whole tympanic nerve to a pulsed note of low pitch cannot be made identical to the response to the same pulse at high pitch no matter how the relative inten­sities are adjusted. A continuous note, which presumably adapts some but not all of the primary receptors, modifies the relation between pre- and post-ganglionic responses in a way which depends on the pitch of the continuous note. The relative intensities of a pure tone of high pitch (10 to 15 kc/s) and one of low pitch (0.5 to 2.0 kc/s) can, in a preparation showing only ‘on' responses, be adjusted so that there is a post-ganglionic response to the former but not to the latter, although the latter causes a larger response in the tympanic nerve. Certain large interneurones, identifiable by their spike height, do not have the same curve of threshold to pulses of various pitch as does the summed response from the whole tympanic nerve. The post-ganglionic response is, therefore, towards a selected fraction of the sensory axons. In each of the above tests the effects are small and pitch discrimination cannot be of great significance for the life of the animal.

Directional Sensitivity of the Ears of Noctuid Moths

1966 ◽  
Vol 44 (1) ◽  
pp. 17-31
Author(s):  
R. S. PAYNE ◽  
K. D. ROEDER ◽  
J. WALLMAN
Keyword(s):  
Sound Source ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Sound Intensity ◽  
Contralateral Side ◽  
The Body ◽  
Body Axis ◽  
Directional Sensitivity ◽  
Tympanic Organ ◽  
Three Dimensional Space

1. Noctuid moths of several species were mounted at the tip of a tower of fine tubing in acoustic ‘free space’. Recordings were made of the intensity of a brief pulse of ultrasound necessary to produce a constant tympanic nerve response for any angle of sound presentation relative to the moth's body axis. Such plots of intensity versus angle were made with the wings held in several postures approximating those assumed in normal flight. 2. The data indicate that sound intensity reaching the tympanic organ can vary by as much as 40 db. depending upon: (a) the position of a sound source relative to the moth's body axis, and (b) the position of its wings. 3. With wings above the horizontal plane each ear reports sounds c. 20-40 db. louder on the ipsilateral side than on the contralateral side. With wings below the horizontal, the lateral asymmetries are replaced by a dorsoventral asymmetry in which each ear reports sounds coming from below the body c. 10-25 db. louder than sounds coming from above. 4. Directional sensitivity plots at 60 kcyc./sec. are more complex than plots at 30 kcyc./sec.--as expected. 5. A theory is presented to explain how a moth could determine the direction of a sound source in three-dimensional space by comparing the intensity reports of both tympanic organs during a complete wing cycle.

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