Address JR Trimarchi, Cornell Univ, Neurobiol & Behav Sect, Seeley G Mudd Hall, Ithaca, NY 14853 USA
ISBN/ISSN 0021-9967
Publisher Wiley-Liss, Div John Wiley & Sons Inc, 605 Third Ave, New York, NY 10158-0012
Abstract The anatomy of the motor neurons innervating six direct flight muscles in Drosophila melanogaster has been investigated by using a horseradish peroxidase backfilling technique. The somata of these motor neurons are arranged in two distinct clusters ipsilateral to the muscle they innervate. One cluster of cell bodies is located in the ventrolateral region between the prothoracic neuromere and the mesothoracic leg-related neuropil and the other is situated dorsally and posteriorly to the mesothoracic leg-related neuropil. Axons from somata in the ventrolateral cluster run in the anterior dorsal mesothoracic nerve, while axons from somata in the other cluster run in the mesothoracic accessory nerve. This distribution of somata and axons is discussed in the light of the morphological similarity and proximity of these functionally related muscles.
On the basis of the branching patterns of their neurites, direct flight muscle motor neurons can be classified as stubbly, fibrous or tufted. The terminal arborizations of the motor neurons over the direct flight muscles are also morphologically specialized. Both the central and the peripheral morphological specializations of the direct flight muscle motor neurons correlate with the activity patterns exhibited by their associated muscles during flight and courtship song. (C) 1994 Wiley-Liss, Inc.
Author(s) P Steullet, PM Guerin
Title Identification of Vertebrate Volatiles Stimulating Olfactory Receptors on Tarsus I of the Tick Amblyomma Variegatum Fabricius (Ixodidae) .1. Receptors Within the Hallers Organ Capsule
Source Journal of Comparative Physiology A - Sensory Neural and Behavioral Physiology 174: 1 (JAN 1994)
Publisher Springer Verlag, 175 Fifth Ave, New York, NY 10010
Abstract Gas chromatography-coupled electrophysiological recordings (GC-EL) from olfactory sensilla within the capsule of Haller's organ of the tick Amblyomma variegatum indicate the presence of a number of stimulants in rabbit and bovine odours, and in steer skin wash. Some of these stimulants were fully identified by gas chromatography-mass spectrometry analysis and by matching electrophysiological activity of synthetic analogues as: 1) hexanal, 2-heptenal, nonanal, furfural, benzaldehyde, and 2-hydroxybenzaldehyde (in all extracts); 2) heptanal, 2-, 3-, and 4-methylbenzaldehyde, and gamma-valerolactone (only in bovine and rabbit odour). Careful examination of the electrophysiological responses permit characterization of 6 receptor types: 1) a benzaldehyde receptor, 2) a 2-hydroxybenzaldehyde receptor, 3) three types of receptors responding differently to aliphatic aldehydes, and 4) a lactone receptor.
Author(s) P Steullet, PM Guerin
Title Identification of Vertebrate Volatiles Stimulating Olfactory Receptors on Tarsus I of the Tick Amblyomma Variegatum Fabricius (Ixodidae) .2. Receptors Outside the Hallers Organ Capsule
Source Journal of Comparative Physiology A - Sensory Neural and Behavioral Physiology 174: 1 (JAN 1994)
Publisher Springer Verlag, 175 Fifth Ave, New York, NY 10010
Abstract Bovine odour excites olfactory receptor(s) in a wall-pore olfactory sensillum on the anterior pit of Haller's organ in Amblyomma variegatum. Gas chromatography-coupled electrophysiology recordings from this sensillum reveal the presence of 4 active compounds in bovine odour. The two strongest stimulants were identified as 2-nitrophenol and 4-methyl-2-nitrophenol by gas chromatography-coupled mass spectrometry, and by matching electrophysiological activity of synthetic analogues. Synthetic analogues of known vertebrate-associated volatiles also stimulate other olfactory receptors in sensilla on the surface of tarsus I: a lactone receptor responding to gamma-valerolactone and 6-caprolactone; different fatty acid receptor types responding best to either pentanoic acid, 2-methylpropanoic acid or to butanoic acid; three receptors responding to NH3; and one receptor responding to 3-pentanone. Gas chromatography-coupled mass spectrometry analysis of vertebrate volatiles revealed presence of a number of these olfactory stimulants in concentrates of rabbit and steer odour, i.e. 2-methylpropanoic acid, butanoic acid, 3-methylbutanoic acid, pentanoic acid, and gamma-valerolactone.
Author(s) W Gronenberg, J Tautz
Title The Sensory Basis for the Trap-Jaw Mechanism in the Ant Odontomachus Bauri
Source Journal of Comparative Physiology A - Sensory Neural and Behavioral Physiology 174: 1 (JAN 1994)
KeyWords+ HONEY BEE; FORMICIDAE; PONERINAE; BEHAVIOR; NEURONS; SYSTEM
TGA No. MT795
Discipline Physiology
Document Article
Language English
Address W Gronenberg, Univ Wurzburg, Theodor Boveri Inst, Lehrstuhl Verhaltensphysiol & Soziobiol, Hubland, D-97074 Wurzburg, Germany
ISBN/ISSN 0340-7594
Publisher Springer Verlag, 175 Fifth Ave, New York, NY 10010
Abstract Ants of the ponerine genus Odontomachus have evolved a mechanism that allows them to instantaneously close their long mandibles to catch prey or defend themselves. This trap-jaw action is triggered by contact of trigger hairs with a potential prey item. Two of these long mechanosensory hair sensilla reside proximally on each mandible and are supplied by giant sensory cells.
Extracellular recordings demonstrate that the sensory cells respond to tactile stimulation. Their phasic responses encode amplitude and velocity of hair-deflection away from the midline, but not hair position. The discharge of action potentials follows stimulus frequencies of more than 300 Hz. During sinusoidal stimulation, the cells adapt very little, sustain discharge rates of more than 200 Hz for more than 20 s, and reach peak spike rates of about 450 Hz.
The afferent axons of these sensory cells give rise to huge axon terminals within the suboesophageal ganglion. One of the afferents has a prominent contralateral branch, the other is confined to ipsilateral neuropil. Anatomical data indicate that the 4 afferents may be coupled and may serve as the substrate for a very fast reflex.
Author(s) B Hedwig, J Meyer
Title Auditory Information Processing in Stridulating Grasshoppers - Tympanic Membrane Vibrations and Neurophysiology
Source Journal of Comparative Physiology A - Sensory Neural and Behavioral Physiology 174: 1 (JAN 1994)
Address B Hedwig, Univ Gottingen, Inst Zool 1, Berliner Str 28, D-37073 Gottingen, Germany
ISBN/ISSN 0340-7594
Publisher Springer Verlag, 175 Fifth Ave, New York, NY 10010
Abstract During stridulation in the gomphocerine grasshopper Omocestus viridulus the leg movements, sound pattern and either summed auditory nerve activity or single interneuron activity were recorded. Simultaneous laser interferometric and vibrometric measurements of the displacement and velocity of the tympanic membrane were performed at the pyriform vesicle (d-receptor group). Slow displacements of the tympanic membrane occur in phase with the ventilatory and stridulatory rhythm and reach 10 mu m(peak-peak) and 1-3 mu m(peak-peak) in amplitude, respectively. Additionally, the tympanic membrane oscillates maximally in the range 5-10 kHz. These high-frequency oscillations are due to sound production and motor activity and correspond in amplitude to oscillations evoked by sound pressures of 90-dB SPL. They activate the auditory receptors during most of the stridulatory cycle even during mute stridulation. Only at the lower reversal point of the leg movement are membrane vibrations and receptor activity at a minimum. As a consequence the response of receptors and interneurons to auditory stimuli are generally impaired and an auditory response of receptors and interneurons can be elicited only during a short period at the lower reversal point. Although in this phase of the stridulatory cycle auditory sensitivity is present, males do not show phonotactic responses towards female songs during ongoing own stridulation.
