LOCALIZATION OF PRIMARY SENSORY AFFERENTS IN PROTHORACIC GANGLION OF WOOD ANT (FORMICA LUGUBRIS ZETT) - A COMBINED LIGHT AND ELECTRON MICROSCOPIC STUDY OF SECONDARY DEGENERATION

Secondary degeneration of foreleg afferents was traced in the prothoracic ganglion of the common wood ant (Formica lugubris Zett) with the aid of phase contrast and electron microscopy. The legs were amputated at the coxal level in 43 workers; 1–35 days were allowed for degeneration. Localization of degenerated sensory nerves in the entering nerve root and within the neuropil of the ganglion was opumal after 4‐10 days. Afferent fibers were found predominantly in the ipsilateral half of the ganglion. However, a few fibers seemed to cross the midline and to end in the medial portion of the contralateral side. No degenerations could be located within the cranial and caudal connectives. The significance of the findings with respect to the problem of functional localization pattern in the neuropil of an insect ganglion is discussed. Copyright © 1969 The Wistar Institute Press