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W Kutsch

Publications and source records attributed to W Kutsch.

8 recordsLinked to original sources
PubMed1990

Structural homology of identified motoneurones in larval and adult stages of hemi- and holometabolous insects.

The set of neurones innervating the dorsal longitudinal muscles was studied with cobalt and nickel backfills in: (1) larval and adult locusts (Schistocerca gregaria and Locusta migratoria), (2) the larval and adult beetle (Zophobas morio), and (3) various segments of these insect species. In all specimens 11 neurones were encountered, which can be subdivided into a group of 7 motoneurones that stem from the next anterior ganglion and 4 neurones located in the ganglion of the segment containing the muscles. The latter group comprises 2 contralateral and 2 medial somata, of which one is a dorsal unpaired median neurone. The results were analysed under different aspects. This neural set and the basic structure of the dendritic fields is similar in: (1) different segments (serial homology), (2) the larval stage and imago of the same species with or without a pronounced metamorphosis (ontogeny), and (3) the studied hemi- and holometabolous insects (phylogeny). Our results support the notion that the structure of these neurones is conserved irrespectively of changes in the periphery and strategy of postembryonic development.

Animals↗
PubMed1987

Histological characterization of neurones innervating functionally different muscles of Locusta.

The innervation of four functionally different muscles (subalar, remotor 1, remotor 2, pleuroalar), all served by the same nerve branch, was studied in both winged segments of the locust, Locusta migratoria. Several anatomical techniques were applied: With the cobalt backfill and silver intensification technique four cell types (motoneurone, dorsal unpaired median neurone, common inhibitory neurone, and small median neurone) were demonstrated. Serial sections enabled the morphology of the motoneurones to be described in more detail and in respect to a possible functional organization of the arborizations. A differential staining technique allowed us to stain various neurones in different colours in the same preparation. With this technique the anatomy of both the "rostral" and the "caudal" subalar motoneurones could be described in parallel, thus avoiding errors in comparison due to possible individual variations from preparation to preparation. Axon counts in the peripheral nerve branch enabled us to compile a list of the total innervation for each muscle. Results from other orthopterans are integrated and whether differences in the dendritic fields might be of functional significance is discussed.

Animals↗
PubMed1987

Programmed death of peripheral pioneer neurons in the grasshopper embryo.

The Ti1 pioneer neurons arise at the distal tip of the metathoracic leg in the grasshopper embryo, and are the first neurons in the limb bud to extend axons to the central nervous system (C. M. Bate (1976) Nature (London) 260, 54-56; H. Keshishian (1980) Dev. Biol. 80, 388-397). By providing a neural pathway along which growth cones of later arising neurons migrate, these pioneer axons establish the route of one of the major nerve trunks in the leg (Keshishian, 1980; R. K. Ho and C. S. Goodman (1982) Nature (London) 297, 404-406; D. Bentley and H. Keshishian (1982) Science 218, 1082-1088). Here, we demonstrate that at the 55-59% stage of development, the two Ti1 pioneer neurons undergo programmed death. The role which these pioneers serve in establishing a nerve route appears to be their only function, and may be important for the normal development of the peripheral nervous system. The Ti1 pioneers provide an example of a previously hypothesized class (J. W. Truman (1984) Annu. Rev. Neurosci. 7, 171-188) of programmed neuron death: obsolete neurons whose function was developmental rather than behavioral.

Animals↗
PubMed1981

Dipteran flight motor pattern: invariabilities and changes during postlarval development.

For Calliphora the wingbeat frequency and the underlying motoneuronal activity were recorded during adult life. Wingbeat frequency increases during the ten days following last molt. The activity of motoneurons serving four selected flight muscles (nonfibrillar and fibrillar ones) also increases with age. The motoneuronal activity of young and old flies was analyzed statistically (serial and cross-correlograms, latency and phase histograms). In addition, several wing manipulations were carried out to evaluate the significance of sensory feedback on pattern generation during maturation. These ontogenetic studies suggest a centrally generated motor pattern that (1) is essentially complete with the molt to adulthood, (2) shows a progressive increase in intrinsic activity, and (3) is modulated by sensory feedback from the wing region by the same amount irrespective of age. Similarities in the postlarval development of the flight pattern of neurogenic and myogenic flyers are discussed.

Action Potentials↗
PubMed1980

Light- and electron-microscopic analysis of a complex sensory organ: the tegula of Locusta migratoria.

Structure and organization of the tegula, a cupola-shaped structure located at the anterior base of the wings of locusts, is described using various morphological methods. Based on histological and cytological criteria, two different sensory systems are distinguished: (1) a field of mechanoreceptive hairs, and (2) a chordotonal organ. The total number of sensory cells corresponds to the number of axons within the nerve supporting the tegula. The hairs are situated at the posterior region of the tegula, and each hair is innervated by only one sensory cell. The complex architecture of the chordotonal organ is analyzed and the attachment of the scolopidia to the cuticle is described. A single scolopidium makes contact with several epidermal cells. The attachment cells run in parallel and are oriented longitudinally within the tegula, being connected to each other and to the epidermal cells by desmosomes. A function in relation to wing movements during flight is suggested for the two sensory systems within the "mixed" sense organ, tegula.

Animals↗