Neurons associated with the dorsal longitudinal flight muscles ofDrosophila melanogaster

Abstract

The anatomy of the neurons associated with the six fibers formingthe dorsal longitudinal flight muscle (DLM) of Drosophila melanogaster has been investigated using a horseradish peroxidase label. The two dorsal-most fibers are innervated by the same neuron whose cell body is in the dorsal, contralateral, mesothoracic region of the thoracic ganglion. The ventral-most fourfibers are innervated by four neurons whose cell bodies are clusteredin the ventral, ipsilateral, prothoracic region. The processes ofallfive of these cells ramify extensively in the dorsal part of theipsilateral and contralateral mesothoracic neuromeres. A large interneuron has been discovered which is associated with the DLM and whose cell body is located contralaterally. Several neurons with small cell bodies on the ventral midline of the mesothoracic neuromere are also consistently labeled. A single fiber projects dorsally from a midline cell body, forms a Y-branch near the top of the ganglion and apparently sends an axon into each posterior dorsal mesothoracic nerve (PDMN) subsequently innervating the DLM.