Sensory projections of identified coxal hair sensilla of the scorpionHeterometrus fulvipes (Scorpionidae)

1993 ◽  
Vol 18 (2) ◽  
pp. 247-259 ◽  
Author(s):  
K. Sasira Babu ◽  
K. Sreenivasulu ◽  
V. Sekhar
1966 ◽  
Vol 4 (1) ◽  
pp. 93-94 ◽  
Author(s):  
Richard F. Thompson ◽  
Duane Denny ◽  
Hilton E. Smith

1961 ◽  
Vol 38 (3) ◽  
pp. 545-558 ◽  
Author(s):  
NOBUO SUGA ◽  
YASUJI KATSUKI

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.


2001 ◽  
Vol 204 (24) ◽  
pp. 4301-4309 ◽  
Author(s):  
J. Okada ◽  
Y. Toh

SUMMARY Arthropods have hair plates that are clusters of mechanosensitive hairs, usually positioned close to joints, which function as proprioceptors for joint movement. We investigated how angular movements of the antenna of the cockroach (Periplaneta americana) are coded by antennal hair plates. A particular hair plate on the basal segment of the antenna, the scapal hair plate, can be divided into three subgroups: dorsal, lateral and medial. The dorsal group is adapted to encode the vertical component of antennal direction, while the lateral and medial groups are specialized for encoding the horizontal component. Of the three subgroups of hair sensilla, those of the lateral scapal hair plate may provide the most reliable information about the horizontal position of the antenna, irrespective of its vertical position. Extracellular recordings from representative sensilla of each scapal hair plate subgroup revealed the form of the single-unit impulses in response to hair deflection. The mechanoreceptors were characterized as typically phasic-tonic. The tonic discharge was sustained indefinitely (>20 min) as long as the hair was kept deflected. The spike frequency in the transient (dynamic) phase was both velocity- and displacement-dependent, while that in the sustained (steady) phase was displacement-dependent.


1992 ◽  
Vol 164 (1) ◽  
pp. 205-226 ◽  
Author(s):  
AKIRA CHIBA ◽  
GÜNTER KÄMPER ◽  
R. K. MURPHEY

During postembryonic development of the cricket, the total number of filiform hair sensilla in the cereal sensory system increases approximately 40-fold. In addition, individual receptor hairs grow in size, changing the transducer properties of the sensilla and, thereby, the information transmitted to the central nervous system (CNS) by the sensory neurons. Interneurons MGI and 10–3 receive monosynaptic inputs from these sensory neurons and send outputs to anterior ganglia. We show that, in spite of the changes in the periphery, the response properties of these interneurons are relatively constant during development. The two interneurons differ in their frequency response, intensity response and rate of response decrement. Their respective response properties are conserved during the postembryonic period. The results suggest that systematic rearrangement of the sensory neuron-to-interneuron synapses plays an important role in maintaining a constant output of this sensory system to higher centers of the CNS during maturation of the cricket.


Development ◽  
1994 ◽  
Vol 120 (5) ◽  
pp. 1315-1323 ◽  
Author(s):  
K. Sharma ◽  
Z. Korade ◽  
E. Frank

Development of sensory projections was studied in cultured spinal segments with attached dorsal root ganglia. In spinal segments from stage 30 (E6.5) and older chicken embryos, prelabeled muscle and cutaneous afferents established appropriate projections. Cutaneous afferents terminated solely within the dorsolateral laminae, whereas some muscle afferents (presumably Ia afferents) projected ventrally towards motoneurons. Development of appropriate projections suggests that sufficient cues are preserved in spinal segments to support the formation of modality-specific sensory projections. Further, because these projections developed in the absence of muscle or skin, these results show that the continued presence of peripheral targets is not required for the formation of specific central projections after stage 29 (E6.0). Development of the dorsal horn in cultured spinal segments was assessed using the dorsal midline as a marker. In ovo, this midline structure appears at stage 29. Lack of midline formation in stage 28 and 29 cultured spinal segments suggests that the development of the dorsal horn is arrested in this preparation. This is consistent with earlier reports suggesting that dorsal horn development may be dependent on factors outside the spinal cord. Because dorsal horn development is blocked in cultured spinal segments, this preparation makes it possible to study the consequences of premature ingrowth of sensory axons into the spinal cord. In chicken embryos sensory afferents reach the spinal cord at stage 25 (E4.5) but do not arborize within the gray matter until stage 30. During this period dorsal horn cells are still being generated. In spinal segments, only those segments that have developed a midline at the time of culture support the formation of midline at the time of culture support the formation of specific sensory projections.(ABSTRACT TRUNCATED AT 250 WORDS)


2013 ◽  
Vol 353 (3) ◽  
pp. 399-408 ◽  
Author(s):  
Xin-Cheng Zhao ◽  
Qing-Bo Tang ◽  
Bente G. Berg ◽  
Yang Liu ◽  
Yan-Ru Wang ◽  
...  

Neuron ◽  
1995 ◽  
Vol 14 (5) ◽  
pp. 949-959 ◽  
Author(s):  
Elizabeth K Messersmith ◽  
E.David Leonardo ◽  
Carla J Shatz ◽  
Marc Tessier-Lavigne ◽  
Corey S Goodman ◽  
...  

1980 ◽  
Vol 35 (11-12) ◽  
pp. 990-994 ◽  
Author(s):  
Ernst Priesner

Electrophysiological analysis of olfactory hair sensilla in male P. pisi has revealed four different types of presumed pheromone receptor cells, maximally responsive to (Z)-11-tetradecenyl acetate (Z11-14:Ac), (Z)-9-tetradecenyl acetate (Z9-14:Ac), (Z)-11-hexadecenyl acetate (Z11-14:Ac) and (Z)-7-dodecenyl acetate (Z7-12: Ac), respectively. These four compounds were tested, singly and in various combinations, for efficacy in attracting P. pisi males in the field. High trap catches were obtained with mixtures of Z11-14: Ac/Z9-14: Ac in the ratio 100/100, whereas the 100/30 and 30/100 mixtures of the two compounds were only slightly attractive. No male P. pisi were captured by single chemicals or binary combinations of Z11-14: Ac/Z11-16: Ac, Z11-14:Ac/Z7-12:Ac, Z9-14:Ac/Z11-16:Ac, Z9-14:Ac/Z7-12:Ac, or Z11-16:Ac/Z7-12:Ac. Various compounds, including Z11-16: Ac and Z7-12:Ac, were tried as third chemicals in addi­tion to 100 μg Z11-14: Ac + 100 μg Z9-14: Ac but none increased trap catches over the basic lure.


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